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Sample records for live vaccine vector

  1. Skin vaccination with live virus vectored microneedle arrays induce long lived CD8(+) T cell memory.

    Science.gov (United States)

    Becker, Pablo D; Hervouet, Catherine; Mason, Gavin M; Kwon, Sung-Yun; Klavinskis, Linda S

    2015-09-08

    A simple dissolvable microneedle array (MA) platform has emerged as a promising technology for vaccine delivery, due to needle-free injection with a formulation that preserves the immunogenicity of live viral vectored vaccines dried in the MA matrix. While recent studies have focused largely on design parameters optimized to induce primary CD8(+) T cell responses, the hallmark of a vaccine is synonymous with engendering long-lasting memory. Here, we address the capacity of dried MA vaccination to programme phenotypic markers indicative of effector/memory CD8(+) T cell subsets and also responsiveness to recall antigen benchmarked against conventional intradermal (ID) injection. We show that despite a slightly lower frequency of dividing T cell receptor transgenic CD8(+) T cells in secondary lymphoid tissue at an early time point, the absolute number of CD8(+) T cells expressing an effector memory (CD62L(-)CD127(+)) and central memory (CD62L(+)CD127(+)) phenotype during peak expansion were comparable after MA and ID vaccination with a recombinant human adenovirus type 5 vector (AdHu5) encoding HIV-1 gag. Similarly, both vaccination routes generated CD8(+) memory T cell subsets detected in draining LNs for at least two years post-vaccination capable of responding to secondary antigen. These data suggest that CD8(+) T cell effector/memory generation and long-term memory is largely unaffected by physical differences in vaccine delivery to the skin via dried MA or ID suspension. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Lactobacilli as live vaccine delivery vectors: Progress and prospects

    NARCIS (Netherlands)

    Seegers, J.F.M.L.

    2002-01-01

    Evidence is accumulating that lactobacilli influence the immune response in a strain-dependent manner. This immunomodulatory capacity is important for the development of the immune response, and also identifies Lactobacillus as a potent oral vaccine carrier. Most of our current knowledge of the use

  3. Live-Attenuated Bacterial Vectors: Tools for Vaccine and Therapeutic Agent Delivery

    Directory of Open Access Journals (Sweden)

    Ivan Y. C. Lin

    2015-11-01

    Full Text Available Genetically attenuated microorganisms, including pathogenic and commensal bacteria, can be engineered to carry and deliver heterologous antigens to elicit host immunity against both the vector as well as the pathogen from which the donor gene is derived. These live attenuated bacterial vectors have been given much attention due to their capacity to induce a broad range of immune responses including localized mucosal, as well as systemic humoral and/or cell-mediated immunity. In addition, the unique tumor-homing characteristics of these bacterial vectors has also been exploited for alternative anti-tumor vaccines and therapies. In such approach, tumor-associated antigen, immunostimulatory molecules, anti-tumor drugs, or nucleotides (DNA or RNA are delivered. Different potential vectors are appropriate for specific applications, depending on their pathogenic routes. In this review, we survey and summarize the main features of the different types of live bacterial vectors and discussed the clinical applications in the field of vaccinology. In addition, different approaches for using live attenuated bacterial vectors for anti-cancer therapy is discussed, and some promising pre-clinical and clinical studies in this field are outlined.

  4. Serologic responses after vaccination of fennec foxes (Vulpes zerda) and meerkats (Suricata suricatta) with a live, canarypox-vectored canine distemper virus vaccine.

    Science.gov (United States)

    Coke, Rob L; Backues, Kay A; Hoover, John P; Saliki, Jeremiah T; Ritchey, Jerry W; West, Gary D

    2005-06-01

    Fennec foxes (Vulpes zerda) and meerkats (Suricata suricatta) are considered to be susceptible to canine distemper virus (CDV) infection. Although no definitive clinical cases of natural CDV infections have been reported, mortalities due to CDV have been suspected and are reported in other closely related species. A commercially available monovalent, live, canarypox-vectored CDV vaccine induced neutralizing antibody titers that were maintained for at least a year in both fennec foxes and meerkats.

  5. Transfected Babesia bovis Expressing a Tick GST as a Live Vector Vaccine

    Science.gov (United States)

    Oldiges, Daiane P.; Laughery, Jacob M.; Tagliari, Nelson Junior; Leite Filho, Ronaldo Viana; Davis, William C.; da Silva Vaz, Itabajara; Termignoni, Carlos; Knowles, Donald P.; Suarez, Carlos E.

    2016-01-01

    The Rhipicephalus microplus tick is a notorious blood-feeding ectoparasite of livestock, especially cattle, responsible for massive losses in animal production. It is the main vector for transmission of pathogenic bacteria and parasites, including Babesia bovis, an intraerythrocytic apicomplexan protozoan parasite responsible for bovine Babesiosis. This study describes the development and testing of a live B. bovis vaccine expressing the protective tick antigen glutathione-S-transferase from Haemaphysalis longicornis (HlGST). The B. bovis S74-T3B parasites were electroporated with a plasmid containing the bidirectional Ef-1α (elongation factor 1 alpha) promoter of B. bovis controlling expression of two independent genes, the selectable marker GFP-BSD (green fluorescent protein–blasticidin deaminase), and HlGST fused to the MSA-1 (merozoite surface antigen 1) signal peptide from B. bovis. Electroporation followed by blasticidin selection resulted in the emergence of a mixed B. bovis transfected line (termed HlGST) in in vitro cultures, containing parasites with distinct patterns of insertion of both exogenous genes, either in or outside the Ef-1α locus. A B. bovis clonal line termed HlGST-Cln expressing intracellular GFP and HlGST in the surface of merozoites was then derived from the mixed parasite line HlGST using a fluorescent activated cell sorter. Two independent calf immunization trials were performed via intravenous inoculation of the HlGST-Cln and a previously described control consisting of an irrelevant transfected clonal line of B. bovis designated GFP-Cln. The control GFP-Cln line contains a copy of the GFP-BSD gene inserted into the Ef-1α locus of B. bovis in an identical fashion as the HIGST-Cln parasites. All animals inoculated with the HlGST-Cln and GFP-Cln transfected parasites developed mild babesiosis. Tick egg fertility and fully engorged female tick weight was reduced significantly in R. microplus feeding on HlGST-Cln-immunized calves

  6. Transfected Babesia bovis Expressing a Tick GST as a Live Vector Vaccine.

    Directory of Open Access Journals (Sweden)

    Daiane P Oldiges

    2016-12-01

    Full Text Available The Rhipicephalus microplus tick is a notorious blood-feeding ectoparasite of livestock, especially cattle, responsible for massive losses in animal production. It is the main vector for transmission of pathogenic bacteria and parasites, including Babesia bovis, an intraerythrocytic apicomplexan protozoan parasite responsible for bovine Babesiosis. This study describes the development and testing of a live B. bovis vaccine expressing the protective tick antigen glutathione-S-transferase from Haemaphysalis longicornis (HlGST. The B. bovis S74-T3B parasites were electroporated with a plasmid containing the bidirectional Ef-1α (elongation factor 1 alpha promoter of B. bovis controlling expression of two independent genes, the selectable marker GFP-BSD (green fluorescent protein-blasticidin deaminase, and HlGST fused to the MSA-1 (merozoite surface antigen 1 signal peptide from B. bovis. Electroporation followed by blasticidin selection resulted in the emergence of a mixed B. bovis transfected line (termed HlGST in in vitro cultures, containing parasites with distinct patterns of insertion of both exogenous genes, either in or outside the Ef-1α locus. A B. bovis clonal line termed HlGST-Cln expressing intracellular GFP and HlGST in the surface of merozoites was then derived from the mixed parasite line HlGST using a fluorescent activated cell sorter. Two independent calf immunization trials were performed via intravenous inoculation of the HlGST-Cln and a previously described control consisting of an irrelevant transfected clonal line of B. bovis designated GFP-Cln. The control GFP-Cln line contains a copy of the GFP-BSD gene inserted into the Ef-1α locus of B. bovis in an identical fashion as the HIGST-Cln parasites. All animals inoculated with the HlGST-Cln and GFP-Cln transfected parasites developed mild babesiosis. Tick egg fertility and fully engorged female tick weight was reduced significantly in R. microplus feeding on Hl

  7. Viral Vectors for Use in the Development of Biodefense Vaccines

    National Research Council Canada - National Science Library

    Lee, John S; Hadjipanayis, Angela G; Parker, Michael D

    2005-01-01

    .... DNA vectors, live-attenuated viruses and bacteria, recombinant proteins combined with adjuvant, and viral- or bacterial-vectored vaccines have been developed as countermeasures against many potential...

  8. Use of adenoviral vectors as veterinary vaccines.

    Science.gov (United States)

    Ferreira, T B; Alves, P M; Aunins, J G; Carrondo, M J T

    2005-10-01

    Vaccines are the most effective and inexpensive prophylactic tool in veterinary medicine. Ideally, vaccines should induce a lifelong protective immunity against the target pathogen while not causing clinical or pathological signs of diseases in the vaccinated animals. However, such ideal vaccines are rare in the veterinary field. Many vaccines are either of limited effectiveness or have harmful side effects. In addition, there are still severe diseases with no effective vaccines. A very important criterion for an ideal vaccine in veterinary medicine is low cost; this is especially important in developing countries and even more so for poultry vaccination, where vaccines must sell for a few cents a dose. Traditional approaches include inactivated vaccines, attenuated live vaccines and subunit vaccines. Recently, genetic engineering has been applied to design new, improved vaccines. Adenovirus vectors are highly efficient for gene transfer in a broad spectrum of cell types and species. Moreover, adenoviruses often induce humoral, mucosal and cellular immune responses to antigens encoded by the inserted foreign genes. Thus, adenoviruses have become a vector of choice for delivery and expression of foreign proteins for vaccination. Consequently, the market requirements for adenovirus vaccines are increasing, creating a need for production methodologies of concentrated vectors with warranted purity and efficacy. This review summarizes recent developments and approaches of adenovirus production and purification as the application of these vectors, including successes and failures in clinical applications to date.

  9. Vaccine protection of chickens against antigenically diverse H5 highly pathogenic avian influenza isolates with a live HVT vector vaccine expressing the influenza hemagglutinin gene derived from a clade 2.2 avian influenza virus.

    Science.gov (United States)

    Kapczynski, Darrell R; Esaki, Motoyuki; Dorsey, Kristi M; Jiang, Haijun; Jackwood, Mark; Moraes, Mauro; Gardin, Yannick

    2015-02-25

    Vaccination is an important tool in the protection of poultry against avian influenza (AI). For field use, the overwhelming majority of AI vaccines produced are inactivated whole virus formulated into an oil emulsion. However, recombinant vectored vaccines are gaining use for their ability to induce protection against heterologous isolates and ability to overcome maternal antibody interference. In these studies, we compared protection of chickens provided by a turkey herpesvirus (HVT) vector vaccine expressing the hemagglutinin (HA) gene from a clade 2.2 H5N1 strain (A/swan/Hungary/4999/2006) against homologous H5N1 as well as heterologous H5N1 and H5N2 highly pathogenic (HP) AI challenge. The results demonstrated all vaccinated birds were protected from clinical signs of disease and mortality following homologous challenge. In addition, oral and cloacal swabs taken from challenged birds demonstrated that vaccinated birds had lower incidence and titers of viral shedding compared to sham-vaccinated birds. Following heterologous H5N1 or H5N2 HPAI challenge, 80-95% of birds receiving the HVT vector AI vaccine at day of age survived challenge with fewer birds shedding virus after challenge than sham vaccinated birds. In vitro cytotoxicity analysis demonstrated that splenic T lymphocytes from HVT-vector-AI vaccinated chickens recognized MHC-matched target cells infected with H5, as well as H6, H7, or H9 AI virus. Taken together, these studies provide support for the use of HVT vector vaccines expressing HA to protect poultry against multiple lineages of HPAI, and that both humoral and cellular immunity induced by live vaccines likely contributes to protection. Published by Elsevier Ltd.

  10. Induction of CD8(+) T cell responses and protective efficacy following microneedle-mediated delivery of a live adenovirus-vectored malaria vaccine.

    Science.gov (United States)

    Pearson, Frances E; O'Mahony, Conor; Moore, Anne C; Hill, Adrian V S

    2015-06-22

    There is an urgent need for improvements in vaccine delivery technologies. This is particularly pertinent for vaccination programmes within regions of limited resources, such as those required for adequate provision for disposal of used needles. Microneedles are micron-sized structures that penetrate the stratum corneum of the skin, creating temporary conduits for the needle-free delivery of drugs or vaccines. Here, we aimed to investigate immunity induced by the recombinant simian adenovirus-vectored vaccine ChAd63.ME-TRAP; currently undergoing clinical assessment as a candidate malaria vaccine, when delivered percutaneously by silicon microneedle arrays. In mice, we demonstrate that microneedle-mediated delivery of ChAd63.ME-TRAP induced similar numbers of transgene-specific CD8(+) T cells compared to intradermal (ID) administration with needle-and-syringe, following a single immunisation and after a ChAd63/MVA heterologous prime-boost schedule. When mice immunised with ChAd63/MVA were challenged with live Plasmodium berghei sporozoites, microneedle-mediated ChAd63.ME-TRAP priming demonstrated equivalent protective efficacy as did ID immunisation. Furthermore, responses following ChAd63/MVA immunisation correlated with a specific design parameter of the array used ('total array volume'). The level of transgene expression at the immunisation site and skin-draining lymph node (dLN) was also linked to total array volume. These findings have implications for defining silicon microneedle array design for use with live, vectored vaccines. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. The yellow fever 17D vaccine virus as a vector for the expression of foreign proteins: development of new live flavivirus vaccines

    Directory of Open Access Journals (Sweden)

    Myrna C Bonaldo

    2000-01-01

    Full Text Available The Flaviviridae is a family of about 70 mostly arthropod-borne viruses many of which are major public health problems with members being present in most continents. Among the most important are yellow fever (YF, dengue with its four serotypes and Japanese encephalitis virus. A live attenuated virus is used as a cost effective, safe and efficacious vaccine against YF but no other live flavivirus vaccines have been licensed. The rise of recombinant DNA technology and its application to study flavivirus genome structure and expression has opened new possibilities for flavivirus vaccine development. One new approach is the use of cDNAs encopassing the whole viral genome to generate infectious RNA after in vitro transcription. This methodology allows the genetic mapping of specific viral functions and the design of viral mutants with considerable potential as new live attenuated viruses. The use of infectious cDNA as a carrier for heterologous antigens is gaining importance as chimeric viruses are shown to be viable, immunogenic and less virulent as compared to the parental viruses. The use of DNA to overcome mutation rates intrinsic of RNA virus populations in conjunction with vaccine production in cell culture should improve the reliability and lower the cost for production of live attenuated vaccines. The YF virus despite a long period ignored by researchers probably due to the effectiveness of the vaccine has made a come back, both in nature as human populations grow and reach endemic areas as well as in the laboratory being a suitable model to understand the biology of flaviviruses in general and providing new alternatives for vaccine development through the use of the 17D vaccine strain.

  12. A non-pathogenic live vector as an efficient delivery system in vaccine design for the prevention of HPV16 E7-overexpressing cancers.

    Science.gov (United States)

    Hosseinzadeh, Sahar; Bolhassani, Azam; Rafati, Sima; Taheri, Tahereh; Zahedifard, Farnaz; Daemi, Amin; Taslimi, Yasaman; Hashemi, Mehrdad; Memarnejadian, Arash

    2013-01-01

    The attenuated or non-pathogenic live vectors have been evolved specifically to deliver DNA into cells as efficient delivery tools in gene therapy. Recently, a non-pathogenic protozoan, Leishmania tarentolae (L.tar) has attracted a great attention. In current study, we used Leishmania expression system (LEXSY) for stable expression of HPV16 E7 linked to different mini-chaperones [N-/C-terminal of gp96] and compared their immunogenicity and protective effects in C57BL/6 mice against TC-1 challenge. TC-1 murine model is primary C57BL/6 mice lung epithelial cells co-transformed with HPV16 E6, HPV16 E7 and ras oncogenes. Our results showed that subcutaneous administration of mice with both the recombinant L.tar-E7-NT (gp96) and L.tar-E7-CT (gp96) led to enhance the levels of IFN-γ and also IgG2a before and after challenge with TC-1. Furthermore, L.tar-E7-CT (gp96) live vaccine indicated significant protective effects as compared to control groups as well as group vaccinated with L.tar-E7. Indeed, the recombinant live vector is capable of eliciting effective humoral and cellular immune responses in mice, but however, further studies are required to increase their efficacy.

  13. Virus-Vectored Influenza Virus Vaccines

    Science.gov (United States)

    Tripp, Ralph A.; Tompkins, S. Mark

    2014-01-01

    Despite the availability of an inactivated vaccine that has been licensed for >50 years, the influenza virus continues to cause morbidity and mortality worldwide. Constant evolution of circulating influenza virus strains and the emergence of new strains diminishes the effectiveness of annual vaccines that rely on a match with circulating influenza strains. Thus, there is a continued need for new, efficacious vaccines conferring cross-clade protection to avoid the need for biannual reformulation of seasonal influenza vaccines. Recombinant virus-vectored vaccines are an appealing alternative to classical inactivated vaccines because virus vectors enable native expression of influenza antigens, even from virulent influenza viruses, while expressed in the context of the vector that can improve immunogenicity. In addition, a vectored vaccine often enables delivery of the vaccine to sites of inductive immunity such as the respiratory tract enabling protection from influenza virus infection. Moreover, the ability to readily manipulate virus vectors to produce novel influenza vaccines may provide the quickest path toward a universal vaccine protecting against all influenza viruses. This review will discuss experimental virus-vectored vaccines for use in humans, comparing them to licensed vaccines and the hurdles faced for licensure of these next-generation influenza virus vaccines. PMID:25105278

  14. Chimpanzee Adenovirus Vector Ebola Vaccine.

    Science.gov (United States)

    Ledgerwood, Julie E; DeZure, Adam D; Stanley, Daphne A; Coates, Emily E; Novik, Laura; Enama, Mary E; Berkowitz, Nina M; Hu, Zonghui; Joshi, Gyan; Ploquin, Aurélie; Sitar, Sandra; Gordon, Ingelise J; Plummer, Sarah A; Holman, LaSonji A; Hendel, Cynthia S; Yamshchikov, Galina; Roman, Francois; Nicosia, Alfredo; Colloca, Stefano; Cortese, Riccardo; Bailer, Robert T; Schwartz, Richard M; Roederer, Mario; Mascola, John R; Koup, Richard A; Sullivan, Nancy J; Graham, Barney S

    2017-03-09

    The unprecedented 2014 epidemic of Ebola virus disease (EVD) prompted an international response to accelerate the availability of a preventive vaccine. A replication-defective recombinant chimpanzee adenovirus type 3-vectored ebolavirus vaccine (cAd3-EBO), encoding the glycoprotein from Zaire and Sudan species, that offers protection in the nonhuman primate model, was rapidly advanced into phase 1 clinical evaluation. We conducted a phase 1, dose-escalation, open-label trial of cAd3-EBO. Twenty healthy adults, in sequentially enrolled groups of 10 each, received vaccination intramuscularly in doses of 2×10 10 particle units or 2×10 11 particle units. Primary and secondary end points related to safety and immunogenicity were assessed throughout the first 8 weeks after vaccination; in addition, longer-term vaccine durability was assessed at 48 weeks after vaccination. In this small study, no safety concerns were identified; however, transient fever developed within 1 day after vaccination in two participants who had received the 2×10 11 particle-unit dose. Glycoprotein-specific antibodies were induced in all 20 participants; the titers were of greater magnitude in the group that received the 2×10 11 particle-unit dose than in the group that received the 2×10 10 particle-unit dose (geometric mean titer against the Zaire antigen at week 4, 2037 vs. 331; P=0.001). Glycoprotein-specific T-cell responses were more frequent among those who received the 2×10 11 particle-unit dose than among those who received the 2×10 10 particle-unit dose, with a CD4 response in 10 of 10 participants versus 3 of 10 participants (P=0.004) and a CD8 response in 7 of 10 participants versus 2 of 10 participants (P=0.07) at week 4. Assessment of the durability of the antibody response showed that titers remained high at week 48, with the highest titers in those who received the 2×10 11 particle-unit dose. Reactogenicity and immune responses to cAd3-EBO vaccine were dose-dependent. At

  15. Evaluation of vaccine competition using HVT vector vaccines

    Science.gov (United States)

    Turkey herpesvirus (HVT) has been widely used as a vaccine for Marek’s disease (MD) since the 1970s. Because HVT is a safe vaccine that is poorly sensitive to interference from maternally derived antibodies, it has seen rising use as a vector for vaccines developed for protection against other comm...

  16. Prime-boost vaccination with heterologous live vectors encoding SIV gag and multimeric HIV-1 gp160 protein: efficacy against repeated mucosal R5 clade C SHIV challenges.

    Science.gov (United States)

    Lakhashe, Samir K; Velu, Vijayakumar; Sciaranghella, Gaia; Siddappa, Nagadenahalli B; Dipasquale, Janet M; Hemashettar, Girish; Yoon, John K; Rasmussen, Robert A; Yang, Feng; Lee, Sandra J; Montefiori, David C; Novembre, Francis J; Villinger, François; Amara, Rama Rao; Kahn, Maria; Hu, Shiu-Lok; Li, Sufen; Li, Zhongxia; Frankel, Fred R; Robert-Guroff, Marjorie; Johnson, Welkin E; Lieberman, Judy; Ruprecht, Ruth M

    2011-08-05

    We sought to induce primate immunodeficiency virus-specific cellular and neutralizing antibody (nAb) responses in rhesus macaques (RM) through a bimodal vaccine approach. RM were immunized intragastrically (i.g.) with the live-attenuated Listeria monocytogenes (Lm) vector Lmdd-BdopSIVgag encoding SIVmac239 gag. SIV Gag-specific cellular responses were boosted by intranasal and intratracheal administration of replication-competent adenovirus (Ad5hr-SIVgag) encoding the same gag. To broaden antiviral immunity, the RM were immunized with multimeric HIV clade C (HIV-C) gp160 and HIV Tat. SIV Gag-specific cellular immune responses and HIV-1 nAb developed in some RM. The animals were challenged intrarectally with five low doses of R5 SHIV-1157ipEL-p, encoding a heterologous HIV-C Env (22.1% divergent to the Env immunogen). All five controls became viremic. One out of ten vaccinees was completely protected and another had low peak viremia. Sera from the completely and partially protected RM neutralized the challenge virus > 90%; these RM also had strong SIV Gag-specific proliferation of CD8⁺ T cells. Peak and area under the curve of plasma viremia (during acute phase) among vaccinees was lower than for controls, but did not attain significance. The completely protected RM showed persistently low numbers of the α4β7-expressing CD4⁺ T cells; the latter have been implicated as preferential virus targets in vivo. Thus, vaccine-induced immune responses and relatively lower numbers of potential target cells were associated with protection. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Coated microneedle arrays for transcutaneous delivery of live virus vaccines

    OpenAIRE

    Vrdoljak, Anto; McGrath, Marie G.; Carey, John B.; Draper, Simon J.; Hill, Adrian V.S.; O’Mahony, Conor; Crean, Abina M.; Moore, Anne C.

    2011-01-01

    Vaccines are sensitive biologics that require continuous refrigerated storage to maintain their viability. The vast majority of vaccines are also administered using needles and syringes. The need for cold chain storage and the significant logistics surrounding needle-and-syringe vaccination is constraining the success of immunization programs. Recombinant live viral vectors are a promising platform for the development of vaccines against a number of infectious diseases, however these viruses ...

  18. Progress on adenovirus-vectored universal influenza vaccines.

    Science.gov (United States)

    Xiang, Kui; Ying, Guan; Yan, Zhou; Shanshan, Yan; Lei, Zhang; Hongjun, Li; Maosheng, Sun

    2015-01-01

    Influenza virus (IFV) infection causes serious health problems and heavy financial burdens each year worldwide. The classical inactivated influenza virus vaccine (IIVV) and live attenuated influenza vaccine (LAIV) must be updated regularly to match the new strains that evolve due to antigenic drift and antigenic shift. However, with the discovery of broadly neutralizing antibodies that recognize conserved antigens, and the CD8(+) T cell responses targeting viral internal proteins nucleoprotein (NP), matrix protein 1 (M1) and polymerase basic 1 (PB1), it is possible to develop a universal influenza vaccine based on the conserved hemagglutinin (HA) stem, NP, and matrix proteins. Recombinant adenovirus (rAd) is an ideal influenza vaccine vector because it has an ideal stability and safety profile, induces balanced humoral and cell-mediated immune responses due to activation of innate immunity, provides 'self-adjuvanting' activity, can mimic natural IFV infection, and confers seamless protection against mucosal pathogens. Moreover, this vector can be developed as a low-cost, rapid-response vaccine that can be quickly manufactured. Therefore, an adenovirus vector encoding conserved influenza antigens holds promise in the development of a universal influenza vaccine. This review will summarize the progress in adenovirus-vectored universal flu vaccines and discuss future novel approaches.

  19. 76 FR 3075 - Availability of an Environmental Assessment for Field Testing Feline Leukemia Vaccine, Live...

    Science.gov (United States)

    2011-01-19

    ...] Availability of an Environmental Assessment for Field Testing Feline Leukemia Vaccine, Live Canarypox Vector... Feline Leukemia Vaccine, Live Canarypox Vector. The environmental assessment, which is based on a risk... ADDRESSES above for a link to Regulations.gov ). Requester: Merial, Inc. Product: Feline Leukemia Vaccine...

  20. Poxvirus-vectored vaccines for rabies--a review.

    Science.gov (United States)

    Weyer, Jacqueline; Rupprecht, Charles E; Nel, Louis H

    2009-11-27

    Oral rabies vaccination of target reservoir species has proved to be one of the pillars of successful rabies elimination programs. The use of live attenuated rabies virus vaccines has been extensive but several limitations hamper its future use. A recombinant vaccinia-rabies vaccine has also been successfully used for the oral vaccination of several species. Nevertheless, its lack of efficacy in certain important rabies reservoirs and concerns on the use of this potent live virus as vaccine carrier (vector) impair the expansion of its use for new target species and new areas. Several attenuated and host-restricted poxvirus alternatives, which supposedly offer enhanced safety, have been investigated. Once again, efficacy in certain target species and innocuity through the oral route remain major limitations of these vaccines. Alternative recombinant vaccines using adenovirus as an antigen delivery vector have been extensively investigated and may provide an important addition to the currently available oral rabies vaccine repertoire, but are not the primary subject of this review.

  1. Viral vector-based influenza vaccines

    Science.gov (United States)

    de Vries, Rory D.; Rimmelzwaan, Guus F.

    2016-01-01

    ABSTRACT Antigenic drift of seasonal influenza viruses and the occasional introduction of influenza viruses of novel subtypes into the human population complicate the timely production of effective vaccines that antigenically match the virus strains that cause epidemic or pandemic outbreaks. The development of game-changing vaccines that induce broadly protective immunity against a wide variety of influenza viruses is an unmet need, in which recombinant viral vectors may provide. Use of viral vectors allows the delivery of any influenza virus antigen, or derivative thereof, to the immune system, resulting in the optimal induction of virus-specific B- and T-cell responses against this antigen of choice. This systematic review discusses results obtained with vectored influenza virus vaccines and advantages and disadvantages of the currently available viral vectors. PMID:27455345

  2. Tomorrow's vector vaccines for small ruminants.

    Science.gov (United States)

    Kyriakis, C S

    2015-12-14

    Inactivated and attenuated vaccines have contributed to the control or even the eradication of significant animal pathogens. However, these traditional vaccine technologies have limitations and disadvantages. Inactivated vaccines lack efficacy against certain pathogens, while attenuated vaccines are not always as safe. New technology vaccines, namely DNA and recombinant viral vector vaccines, are being developed and tested against pathogens of small ruminants. These vaccines induce both humoral and cellular immune responses, are safe to manufacture and use and can be utilized in strategies for differentiation of infected from vaccinated animals. Although there are more strict regulatory requirements for the safety standards of these vaccines, once a vaccine platform is evaluated and established, effective vaccines can be rapidly produced and deployed in the field to prevent spread of emerging pathogens. The present article offers an introduction to these next generation technologies and examples of vaccines that have been tested against important diseases of sheep and goats. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Adenovirus-vectored Ebola vaccines.

    Science.gov (United States)

    Gilbert, Sarah C

    2015-01-01

    The 2014 outbreak of Ebola virus disease in West Africa has highlighted the need for the availability of effective vaccines against outbreak pathogens that are suitable for use in frontline workers who risk their own health in the course of caring for those with the disease, and also for members of the community in the affected area. Along with effective contact tracing and quarantine, use of a vaccine as soon as an outbreak is identified could greatly facilitate rapid control and prevent the outbreak from spreading. This review describes the progress that has been made in producing and testing adenovirus-based Ebola vaccines in both pre-clinical and clinical studies, and considers the likely future use of these vaccines.

  4. Coated microneedle arrays for transcutaneous delivery of live virus vaccines.

    Science.gov (United States)

    Vrdoljak, Anto; McGrath, Marie G; Carey, John B; Draper, Simon J; Hill, Adrian V S; O'Mahony, Conor; Crean, Abina M; Moore, Anne C

    2012-04-10

    Vaccines are sensitive biologics that require continuous refrigerated storage to maintain their viability. The vast majority of vaccines are also administered using needles and syringes. The need for cold chain storage and the significant logistics surrounding needle-and-syringe vaccination is constraining the success of immunization programs. Recombinant live viral vectors are a promising platform for the development of vaccines against a number of infectious diseases, however these viruses must retain infectivity to be effective. Microneedles offer an effective and painless method for delivery of vaccines directly into skin that in the future could provide solutions to current vaccination issues. Here we investigated methods of coating live recombinant adenovirus and modified vaccinia virus Ankara (MVA) vectors onto solid microneedle arrays. An effective spray-coating method, using conventional pharmaceutical processes, was developed, in tandem with suitable sugar-based formulations, which produces arrays with a unique coating of viable virus in a dry form around the shaft of each microneedle on the array. Administration of live virus-coated microneedle arrays successfully resulted in virus delivery, transcutaneous infection and induced an antibody or CD8(+) T cell response in mice that was comparable to that obtained by needle-and-syringe intradermal immunization. To our knowledge, this is the first report of successful vaccination with recombinant live viral vectored vaccines coated on microneedle delivery devices. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Coated microneedle arrays for transcutaneous delivery of live virus vaccines

    Science.gov (United States)

    Vrdoljak, Anto; McGrath, Marie G.; Carey, John B.; Draper, Simon J.; Hill, Adrian V.S.; O’Mahony, Conor; Crean, Abina M.; Moore, Anne C.

    2016-01-01

    Vaccines are sensitive biologics that require continuous refrigerated storage to maintain their viability. The vast majority of vaccines are also administered using needles and syringes. The need for cold chain storage and the significant logistics surrounding needle-and-syringe vaccination is constraining the success of immunization programs. Recombinant live viral vectors are a promising platform for the development of vaccines against a number of infectious diseases, however these viruses must retain infectivity to be effective. Microneedles offer an effective and painless method for delivery of vaccines directly into skin that in the future could provide solutions to current vaccination issues. Here we investigated methods of coating live recombinant adenovirus and modified vaccinia virus Ankara (MVA) vectors onto solid microneedle arrays. An effective spray-coating method, using conventional pharmaceutical processes, was developed, in tandem with suitable sugar-based formulations, which produces arrays with a unique coating of viable virus in a dry form around the shaft of each microneedle on the array. Administration of live virus-coated microneedle arrays successfully resulted in virus delivery, transcutaneous infection and induced an antibody or CD8+ T cell response in mice that was comparable to that obtained by needle-and-syringe intradermal immunization. To our knowledge, this is the first report of successful vaccination with recombinant live viral vectored vaccines coated on microneedle delivery devices. PMID:22245683

  6. Enhancing poxvirus vectors vaccine immunogenicity.

    Science.gov (United States)

    García-Arriaza, Juan; Esteban, Mariano

    2014-01-01

    Attenuated recombinant poxvirus vectors expressing heterologous antigens from pathogens are currently at various stages in clinical trials with the aim to establish their efficacy. This is because these vectors have shown excellent safety profiles, significant immunogenicity against foreign expressed antigens and are able to induce protective immune responses. In view of the limited efficacy triggered by some poxvirus strains used in clinical trials (i.e, ALVAC in the RV144 phase III clinical trial for HIV), and of the restrictive replication capacity of the highly attenuated vectors like MVA and NYVAC, there is a consensus that further improvements of these vectors should be pursuit. In this review we considered several strategies that are currently being implemented, as well as new approaches, to improve the immunogenicity of the poxvirus vectors. This includes heterologous prime/boost protocols, use of co-stimulatory molecules, deletion of viral immunomodulatory genes still present in the poxvirus genome, enhancing virus promoter strength, enhancing vector replication capacity, optimizing expression of foreign heterologous sequences, and the combined use of adjuvants. An optimized poxvirus vector triggering long-lasting immunity with a high protective efficacy against a selective disease should be sought.

  7. LIVE ATTENUATED VACCINES FOR THE IMMUNOPROPHYLAXIS

    Directory of Open Access Journals (Sweden)

    O. A. Shamsutdinova

    2017-01-01

    Full Text Available The review focuses on the history of the production of live antiviral vaccines and their use for the prevention of infectious diseases. It was noted that before the beginning of the 20th century, only three live vaccines were developed and put into practice — against smallpox, rabies, plague. The discovery of D. Enders, T.H. Weller and F.Ch. Robins of the ability of the polio virus, and then of a number of other viruses, to reproduce in vitro in cell cultures of various types, greatly expanded the studies on the production of attenuated strains of viruses for live vaccines. The historical stages of obtaining and introducing live vaccines for the prevention of smallpox, poliomyelitis, measles, rubella, and mumps are highlighted. Arguments in favor of the use of associated vaccine preparations for the prevention of viral infections are presented. Various variants of the strategy and tactics of using live vaccines, which are used for specific prevention of viral infections in different countries, are described. The review provides information on technological methods for obtaining antiviral vaccines. The publications testifying to the development of specific reactions in immunized vaccine strains of measles, mumps, poliomyelitis and rubella viruses, such as aseptic meningitis (vaccine strains of mumps virus, acute arthritis (vaccine rubella virus strains, temperature reactions, rash (vaccine strains of the virus Measles, vaccine-associated paralytic poliomyelitis (VAPP vaccine vaccine poliovirus. It is particularly noted that the long experience of vaccine prevention both in Russia and abroad convincingly shows that the risk of developing post-vaccination complications is incommensurably lower than the risk of causing harm to health from the corresponding infections. It is concluded that despite introduction of new third and fourth generation vaccines into practice, live attenuated vaccines do not lose their significance and are used in vaccine

  8. Unique Safety Issues Associated with Virus Vectored Vaccines: Potential for and Theoretical Consequences of Recombination with Wild Type Virus Strains

    Science.gov (United States)

    Condit, Richard C.; Williamson, Anna-Lise; Sheets, Rebecca; Seligman, Stephen J.; Monath, Thomas P.; Excler, Jean-Louis; Gurwith, Marc; Bok, Karin; Robertson, James S.; Kim, Denny; Hendry, Michael; Singh, Vidisha; Mac, Lisa M.; Chen, Robert T.

    2016-01-01

    In 2003 and 2013, the World Health Organization convened informal consultations on characterization and quality aspects of vaccines based on live virus vectors. In the resulting reports, one of several issues raised for future study was the potential for recombination of virus-vectored vaccines with wild type pathogenic virus strains. This paper presents an assessment of this issue formulated by the Brighton Collaboration. To provide an appropriate context for understanding the potential for recombination of virus-vectored vaccines, we review briefly the current status of virus vectored vaccines, mechanisms of recombination between viruses, experience with recombination involving live attenuated vaccines in the field, and concerns raised previously in the literature regarding recombination of virus-vectored vaccines with wild type virus strains. We then present a discussion of the major variables that could influence recombination between a virus-vectored vaccine and circulating wild type virus and the consequences of such recombination, including intrinsic recombination properties of the parent virus used as a vector; sequence relatedness of vector and wild virus; virus host range, pathogenesis and transmission; replication competency of vector in target host; mechanism of vector attenuation; additional factors potentially affecting virulence; and circulation of multiple recombinant vectors in the same target population. Finally, we present some guiding principles for vector design and testing intended to anticipate and mitigate the potential for and consequences of recombination of virus-vectored vaccines with wild type pathogenic virus strains. PMID:27346303

  9. Construction and evaluation of novel rhesus monkey adenovirus vaccine vectors.

    Science.gov (United States)

    Abbink, Peter; Maxfield, Lori F; Ng'ang'a, David; Borducchi, Erica N; Iampietro, M Justin; Bricault, Christine A; Teigler, Jeffrey E; Blackmore, Stephen; Parenteau, Lily; Wagh, Kshitij; Handley, Scott A; Zhao, Guoyan; Virgin, Herbert W; Korber, Bette; Barouch, Dan H

    2015-02-01

    Adenovirus vectors are widely used as vaccine candidates for a variety of pathogens, including HIV-1. To date, human and chimpanzee adenoviruses have been explored in detail as vaccine vectors. The phylogeny of human and chimpanzee adenoviruses is overlapping, and preexisting humoral and cellular immunity to both are exhibited in human populations worldwide. More distantly related adenoviruses may therefore offer advantages as vaccine vectors. Here we describe the primary isolation and vectorization of three novel adenoviruses from rhesus monkeys. The seroprevalence of these novel rhesus monkey adenovirus vectors was extremely low in sub-Saharan Africa human populations, and these vectors proved to have immunogenicity comparable to that of human and chimpanzee adenovirus vaccine vectors in mice. These rhesus monkey adenoviruses phylogenetically clustered with the poorly described adenovirus species G and robustly stimulated innate immune responses. These novel adenoviruses represent a new class of candidate vaccine vectors. Although there have been substantial efforts in the development of vaccine vectors from human and chimpanzee adenoviruses, far less is known about rhesus monkey adenoviruses. In this report, we describe the isolation and vectorization of three novel rhesus monkey adenoviruses. These vectors exhibit virologic and immunologic characteristics that make them attractive as potential candidate vaccine vectors for both HIV-1 and other pathogens. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  10. Immunogenicity and efficacy of a chimpanzee adenovirus-vectored Rift Valley fever vaccine in mice.

    OpenAIRE

    Warimwe, GM; Lorenzo, G; Lopez-Gil, E; Reyes-Sandoval, A; Cottingham, MG; Spencer, AJ; Collins, KA; Dicks, MD; Milicic, A; Lall, A; Furze, J; Turner, AV; Hill, AV; Brun, A; Gilbert, SC

    2013-01-01

    BACKGROUND: Rift Valley Fever (RVF) is a viral zoonosis that historically affects livestock production and human health in sub-Saharan Africa, though epizootics have also occurred in the Arabian Peninsula. Whilst an effective live-attenuated vaccine is available for livestock, there is currently no licensed human RVF vaccine. Replication-deficient chimpanzee adenovirus (ChAd) vectors are an ideal platform for development of a human RVF vaccine, given the low prevalence of neutralizing antibod...

  11. Live recombinant BHV/BRSV vaccine

    NARCIS (Netherlands)

    Keil, G.M.; Rijsewijk, F.A.M.

    1998-01-01

    The present invention refers to synthetic Bovine Respiratory Syncytium virus genes. Also the invention relates to live attenuated Bovine Herpesvirus recombinants carrying such synthetic genes. Furthermore, the invention relates to vaccines based on these live attenuated recombinants, for the

  12. Single-cycle adenovirus vectors in the current vaccine landscape.

    Science.gov (United States)

    Barry, Michael

    2018-02-01

    Traditional inactivated and protein vaccines generate strong antibodies, but struggle to generate T cell responses. Attenuated pathogen vaccines generate both, but risk causing the disease they aim to prevent. Newer gene-based vaccines drive both responses and avoid the risk of infection. While these replication-defective (RD) vaccines work well in small animals, they can be weak in humans because they do not replicate antigen genes like more potent replication-competent (RC) vaccines. RC vaccines generate substantially stronger immune responses, but also risk causing their own infections. To circumvent these problems, we developed single-cycle adenovirus (SC-Ad) vectors that amplify vaccine genes, but that avoid the risk of infection. This review will discuss these vectors and their prospects for use as vaccines. Areas covered: This review provides a background of different types of vaccines. The benefits of gene-based vaccines and their ability to replicate antigen genes are described. Adenovirus vectors are discussed and compared to other vaccine types. Replication-defective, single-cycle, and replication-competent Ad vaccines are compared. Expert commentary: The potential utility of these vaccines are discussed when used against infectious diseases and as cancer vaccines. We propose a move away from replication-defective vaccines towards more robust replication-competent or single-cycle vaccines.

  13. Severe acute respiratory syndrome vaccine efficacy in ferrets: whole killed virus and adenovirus-vectored vaccines.

    Science.gov (United States)

    See, Raymond H; Petric, Martin; Lawrence, David J; Mok, Catherine P Y; Rowe, Thomas; Zitzow, Lois A; Karunakaran, Karuna P; Voss, Thomas G; Brunham, Robert C; Gauldie, Jack; Finlay, B Brett; Roper, Rachel L

    2008-09-01

    Although the 2003 severe acute respiratory syndrome (SARS) outbreak was controlled, repeated transmission of SARS coronavirus (CoV) over several years makes the development of a SARS vaccine desirable. We performed a comparative evaluation of two SARS vaccines for their ability to protect against live SARS-CoV intranasal challenge in ferrets. Both the whole killed SARS-CoV vaccine (with and without alum) and adenovirus-based vectors encoding the nucleocapsid (N) and spike (S) protein induced neutralizing antibody responses and reduced viral replication and shedding in the upper respiratory tract and progression of virus to the lower respiratory tract. The vaccines also diminished haemorrhage in the thymus and reduced the severity and extent of pneumonia and damage to lung epithelium. However, despite high neutralizing antibody titres, protection was incomplete for all vaccine preparations and administration routes. Our data suggest that a combination of vaccine strategies may be required for effective protection from this pathogen. The ferret may be a good model for SARS-CoV infection because it is the only model that replicates the fever seen in human patients, as well as replicating other SARS disease features including infection by the respiratory route, clinical signs, viral replication in upper and lower respiratory tract and lung damage.

  14. Vaxvec: The first web-based recombinant vaccine vector database and its data analysis

    Science.gov (United States)

    Deng, Shunzhou; Martin, Carly; Patil, Rasika; Zhu, Felix; Zhao, Bin; Xiang, Zuoshuang; He, Yongqun

    2015-01-01

    A recombinant vector vaccine uses an attenuated virus, bacterium, or parasite as the carrier to express a heterologous antigen(s). Many recombinant vaccine vectors and related vaccines have been developed and extensively investigated. To compare and better understand recombinant vectors and vaccines, we have generated Vaxvec (http://www.violinet.org/vaxvec), the first web-based database that stores various recombinant vaccine vectors and those experimentally verified vaccines that use these vectors. Vaxvec has now included 59 vaccine vectors that have been used in 196 recombinant vector vaccines against 66 pathogens and cancers. These vectors are classified to 41 viral vectors, 15 bacterial vectors, 1 parasitic vector, and 1 fungal vector. The most commonly used viral vaccine vectors are double-stranded DNA viruses, including herpesviruses, adenoviruses, and poxviruses. For example, Vaxvec includes 63 poxvirus-based recombinant vaccines for over 20 pathogens and cancers. Vaxvec collects 30 recombinant vector influenza vaccines that use 17 recombinant vectors and were experimentally tested in 7 animal models. In addition, over 60 protective antigens used in recombinant vector vaccines are annotated and analyzed. User-friendly web-interfaces are available for querying various data in Vaxvec. To support data exchange, the information of vaccine vectors, vaccines, and related information is stored in the Vaccine Ontology (VO). Vaxvec is a timely and vital source of vaccine vector database and facilitates efficient vaccine vector research and development. PMID:26403370

  15. Influenza Vaccination Strategies: Comparing Inactivated and Live Attenuated Influenza Vaccines

    Directory of Open Access Journals (Sweden)

    Saranya Sridhar

    2015-04-01

    Full Text Available Influenza is a major respiratory pathogen causing annual outbreaks and occasional pandemics. Influenza vaccination is the major method of prophylaxis. Currently annual influenza vaccination is recommended for groups at high risk of complications from influenza infection such as pregnant women, young children, people with underlying disease and the elderly, along with occupational groups such a healthcare workers and farm workers. There are two main types of vaccines available: the parenteral inactivated influenza vaccine and the intranasal live attenuated influenza vaccine. The inactivated vaccines are licensed from 6 months of age and have been used for more than 50 years with a good safety profile. Inactivated vaccines are standardized according to the presence of the viral major surface glycoprotein hemagglutinin and protection is mediated by the induction of vaccine strain specific antibody responses. In contrast, the live attenuated vaccines are licensed in Europe for children from 2–17 years of age and provide a multifaceted immune response with local and systemic antibody and T cell responses but with no clear correlate of protection. Here we discuss the immunological immune responses elicited by the two vaccines and discuss future work to better define correlates of protection.

  16. Influenza (Flu) vaccine (Live, Intranasal): What you need to know

    Science.gov (United States)

    ... is taken in its entirety from the CDC Influenza Live, Intranasal Flu Vaccine Information Statement (VIS): www.cdc.gov/vaccines/ ... flulive.html . CDC review information for Live, Intranasal Influenza VIS: Vaccine Information Statement Influenza Page last reviewed: ...

  17. Vaccination strategies for SIR vector-transmitted diseases.

    Science.gov (United States)

    Cruz-Pacheco, Gustavo; Esteva, Lourdes; Vargas, Cristobal

    2014-08-01

    Vector-borne diseases are one of the major public health problems in the world with the fastest spreading rate. Control measures have been focused on vector control, with poor results in most cases. Vaccines should help to reduce the diseases incidence, but vaccination strategies should also be defined. In this work, we propose a vector-transmitted SIR disease model with age-structured population subject to a vaccination program. We find an expression for the age-dependent basic reproductive number R(0), and we show that the disease-free equilibrium is locally stable for R(0) ≤ 1, and a unique endemic equilibrium exists for R(0) > 1. We apply the theoretical results to public data to evaluate vaccination strategies, immunization levels, and optimal age of vaccination for dengue disease.

  18. Vaccination of School Children With Live Mumps Virus Vaccine

    Science.gov (United States)

    Furesz, J.; Nagler, F. P.

    1970-01-01

    Live, attenuated mumps virus vaccine (Mumpsvax) was administered to 146 school children 6 to 9 years of age. One child developed clinical mumps nine days after vaccination; epidemiological and serological data strongly suggest that this child had become infected before vaccination. Apart from this single instance there were no apparent clinical reactions that could be ascribed to the administration of the vaccine. Sixty-three of the 146 children with no clinical history of mumps had an initial serum neutralizing antibody titre of less than 1:2. Specific antibodies to mumps virus were detected in 93.5% of the sera of the susceptible children 28 days after vaccination, and the geometric mean antibody titre of these sera was low (1:6). Of the 80 initially seropositive children 21 (26.2%) showed a significant antibody response to the vaccine and this was influenced by the pre-existing antibody level. These data have further demonstrated the safety and efficacy of the live mumps vaccine in children. PMID:5420994

  19. Vector vaccines for control of avian influenza

    Science.gov (United States)

    Vaccines play a critical role in the poultry industries efforts at disease control and prevention. However, providing safe, efficacious, and cost-effective vaccines remains a constant issue to the industry. In addition, many viruses undergo mutation in the field requiring vaccine adjustments. Recent...

  20. Live recombinant BHV/BRSV vaccine

    OpenAIRE

    Keil, G.M.; Rijsewijk, F.A.M.

    1998-01-01

    The present invention refers to synthetic Bovine Respiratory Syncytium virus genes. Also the invention relates to live attenuated Bovine Herpesvirus recombinants carrying such synthetic genes. Furthermore, the invention relates to vaccines based on these live attenuated recombinants, for the protection of cattle against both Bovine herpesvirus infection and against Bovine Respiratory Syncytium virus infection. Also the invention relates to methods for the preparation of such live attenuated r...

  1. Viral Vectors for Use in the Development of Biodefense Vaccines

    National Research Council Canada - National Science Library

    Lee, John S; Hadjipanayis, Angela G; Parker, Michael D

    2005-01-01

    ... agents of bioterrorism or biowarfare. The use of viruses, for example adenovirus, vaccinia virus, and Venezuelan equine encephalitis virus, as vaccine-vectors has enabled researchers to develop effective means for countering the threat of bioterrorism and biowarfare. An overview of the different viral vectors and the threats they counter will be discussed.

  2. Microneedle-mediated delivery of viral vectored vaccines.

    Science.gov (United States)

    Zaric, Marija; Ibarzo Yus, Bárbara; Kalcheva, Petya Petrova; Klavinskis, Linda Sylvia

    2017-10-01

    Microneedle array platforms are a promising technology for vaccine delivery, due to their ease of administration with no sharp waste generated, small size, possibility of targeted delivery to the specified skin depth and efficacious delivery of different vaccine formulations, including viral vectors. Areas covered: Attributes and challenges of the most promising viral vector candidates that have advanced to the clinic and that have been leveraged for skin delivery by microneedles; The importance of understanding the immunobiology of antigen-presenting cells in the skin, in particular dendritic cells, in order to generate further improved skin vaccination strategies; recent studies where viral vectors expressing various antigens have been coupled with microneedle technology to examine their potential for improved vaccination. Expert opinion: Simple, economic and efficacious vaccine delivery methods are needed to improve health outcomes and manage possible outbreaks of new emerging viruses. Understanding what innate/inflammatory signals are required to induce both immediate and long-term responses remains a major hurdle in the development of the effective vaccines. One approach to meet these needs is microneedle-mediated viral vector vaccination. In order for this technology to fulfil this potential the industry must invest significantly to further develop its design, production, biosafety, delivery and large-scale manufacturing.

  3. Chikungunya Virus Vaccines: Viral Vector-Based Approaches.

    Science.gov (United States)

    Ramsauer, Katrin; Tangy, Frédéric

    2016-12-15

    In 2013, a major chikungunya virus (CHIKV) epidemic reached the Americas. In the past 2 years, >1.7 million people have been infected. In light of the current epidemic, with millions of people in North and South America at risk, efforts to rapidly develop effective vaccines have increased. Here, we focus on CHIKV vaccines that use viral-vector technologies. This group of vaccine candidates shares an ability to potently induce humoral and cellular immune responses by use of highly attenuated and safe vaccine backbones. So far, well-described vectors such as modified vaccinia virus Ankara, complex adenovirus, vesicular stomatitis virus, alphavirus-based chimeras, and measles vaccine Schwarz strain (MV/Schw) have been described as potential vaccines. We summarize here the recent data on these experimental vaccines, with a focus on the preclinical and clinical activities on the MV/Schw-based candidate, which is the first CHIKV-vectored vaccine that has completed a clinical trial. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  4. An Adenoviral Vector Based Vaccine for Rhodococcus equi.

    Directory of Open Access Journals (Sweden)

    Carla Giles

    Full Text Available Rhodococcus equi is a respiratory pathogen which primarily infects foals and is endemic on farms around the world with 50% mortality and 80% morbidity in affected foals. Unless detected early and treated appropriately the disease can be fatal. Currently, there is no vaccine available to prevent this disease. For decades researchers have endeavoured to develop an effective vaccine to no avail. In this study a novel human adenoviral vector vaccine for R. equi was developed and tested in the mouse model. This vaccine generated a strong antibody and cytokine response and clearance of R. equi was demonstrated following challenge. These results show that this vaccine could potentially be developed further for use as a vaccine to prevent R. equi disease in foals.

  5. 9 CFR 113.312 - Rabies Vaccine, Live Virus.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Rabies Vaccine, Live Virus. 113.312... Virus Vaccines § 113.312 Rabies Vaccine, Live Virus. Rabies Vaccine shall be prepared from virus-bearing... administration. (iii) Observe all animals for signs of rabies until scheduled time to sacrifice. If animals show...

  6. Immunogenicity and efficacy of a chimpanzee adenovirus-vectored Rift Valley fever vaccine in mice.

    Science.gov (United States)

    Warimwe, George M; Lorenzo, Gema; Lopez-Gil, Elena; Reyes-Sandoval, Arturo; Cottingham, Matthew G; Spencer, Alexandra J; Collins, Katharine A; Dicks, Matthew D J; Milicic, Anita; Lall, Amar; Furze, Julie; Turner, Alison V; Hill, Adrian V S; Brun, Alejandro; Gilbert, Sarah C

    2013-12-05

    Rift Valley Fever (RVF) is a viral zoonosis that historically affects livestock production and human health in sub-Saharan Africa, though epizootics have also occurred in the Arabian Peninsula. Whilst an effective live-attenuated vaccine is available for livestock, there is currently no licensed human RVF vaccine. Replication-deficient chimpanzee adenovirus (ChAd) vectors are an ideal platform for development of a human RVF vaccine, given the low prevalence of neutralizing antibodies against them in the human population, and their excellent safety and immunogenicity profile in human clinical trials of vaccines against a wide range of pathogens. Here, in BALB/c mice, we evaluated the immunogenicity and efficacy of a replication-deficient chimpanzee adenovirus vector, ChAdOx1, encoding the RVF virus envelope glycoproteins, Gn and Gc, which are targets of virus neutralizing antibodies. The ChAdOx1-GnGc vaccine was assessed in comparison to a replication-deficient human adenovirus type 5 vector encoding Gn and Gc (HAdV5-GnGc), a strategy previously shown to confer protective immunity against RVF in mice. A single immunization with either of the vaccines conferred protection against RVF virus challenge eight weeks post-immunization. Both vaccines elicited RVF virus neutralizing antibody and a robust CD8+ T cell response. Together the results support further development of RVF vaccines based on replication-deficient adenovirus vectors, with ChAdOx1-GnGc being a potential candidate for use in future human clinical trials.

  7. Prior DNA vaccination does not interfere with the live-attenuated measles vaccine.

    Science.gov (United States)

    Premenko-Lanier, Mary; Rota, Paul; Rhodes, Gary; Bellini, William; McChesney, Michael

    2004-01-26

    The currently used live-attenuated measles vaccine is very effective although maternal antibody prevents its administration prior to 6 months of age. We are investigating the ability of a DNA vaccine encoding the measles viral hemagglutinin, fusion and nucleoprotein to protect newborn infants from measles. Here, we show that a measles DNA vaccine protects juvenile macaques from pathogenic measles virus challenge and that macaques primed and boosted with this DNA vaccine have anemnestic antibody and cell-mediated responses after vaccination with a live-attenuated canine distemper-measles vaccine. Therefore, this DNA vaccine administered to newborn infants may not hinder the subsequent use of live-attenuated measles vaccine.

  8. Non-Replicating Adenovirus-Vectored Anthrax Vaccine

    International Nuclear Information System (INIS)

    Van Kampen, K. R.; Zhang, J.; Jex, E.; Tang, D. C.

    2007-01-01

    As bioterrorism is emerging as a national threat, it is urgent to develop a new generation of anthrax vaccines that can be rapidly produced and mass administered in an emergency setting. We have demonstrated that protective immunity against anthrax spores could be elicited in mice by intranasal administration of a non-replicating human adenovirus serotype 5 (Ad5)-derived vector encoding Bacillus anthracis protective antigen (PA) in a single-dose regimen. The potency of an Ad5 vector encoding PA was remarkably enhanced by codon optimization of the PA gene to match the tRNA pool found in human cells. This nasal vaccine can be mass-administered by non-medical personnel during a bioterrorist attack. In addition, replication-competent adenovirus (RCA)-free Ad5-vectored anthrax vaccines can be mass produced in PER.C6 cells in serum-free wave bioreactors and purified by column chromatography to meet a surge in demand. The non-replicating nature of this new generation of anthrax vaccine ensures an excellent safety profile for vaccines and the environment.(author)

  9. Emerging Cancer Vaccines: The Promise of Genetic Vectors

    International Nuclear Information System (INIS)

    Aurisicchio, Luigi; Ciliberto, Gennaro

    2011-01-01

    Therapeutic vaccination against cancer is an important approach which, when combined with other therapies, can improve long-term control of cancer. In fact, the induction of adaptive immune responses against Tumor Associated Antigens (TAAs) as well as innate immunity are important factors for tumor stabilization/eradication. A variety of immunization technologies have been explored in last decades and are currently under active evaluation, such as cell-based, protein, peptide and heat-shock protein-based cancer vaccines. Genetic vaccines are emerging as promising methodologies to elicit immune responses against a wide variety of antigens, including TAAs. Amongst these, Adenovirus (Ad)-based vectors show excellent immunogenicity profile and have achieved immunological proof of concept in humans. In vivo electroporation of plasmid DNA (DNA-EP) is also a desirable vaccine technology for cancer vaccines, as it is repeatable several times, a parameter required for the long-term maintenance of anti-tumor immunity. Recent findings show that combinations of different modalities of immunization (heterologous prime/boost) are able to induce superior immune reactions as compared to single-modality vaccines. In this review, we will discuss the challenges and requirements of emerging cancer vaccines, particularly focusing on the genetic cancer vaccines currently under active development and the promise shown by Ad and DNA-EP heterologous prime-boost

  10. Potency Studies of live- Attenuated Viral Vaccines Administered in ...

    African Journals Online (AJOL)

    We critically carried out a potency study in 1992 and 1997 on measles and poliovirus vaccines administered at five different vaccination centers in the metropolitan Lagos, Nigeria. using WHO guidelines on titration of live- viral vaccines, our results revealed that only 6 (16.7%) of 36 measles vaccine (MV) vials and 11 ...

  11. Infectivity of attenuated poxvirus vaccine vectors and immunogenicity of a raccoonpox vectored rabies vaccine in the Brazilian Free-tailed bat (Tadarida brasiliensis)

    Science.gov (United States)

    Stading, Benjamin; Osorio, Jorge E.; Velasco-Villa, Andres; Smotherman, Michael; Kingstad-Bakke, Brock; Rocke, Tonie E.

    2016-01-01

    Bats (Order Chiroptera) are an abundant group of mammals with tremendous ecological value as insectivores and plant dispersers, but their role as reservoirs of zoonotic diseases has received more attention in the last decade. With the goal of managing disease in free-ranging bats, we tested modified vaccinia Ankara (MVA) and raccoon poxvirus (RCN) as potential vaccine vectors in the Brazilian Free-tailed bat (Tadarida brasiliensis), using biophotonic in vivo imaging and immunogenicity studies. Animals were administered recombinant poxviral vectors expressing the luciferase gene (MVA-luc, RCN-luc) through oronasal (ON) or intramuscular (IM) routes and subsequently monitored for bioluminescent signal indicative of viral infection. No clinical illness was noted after exposure to any of the vectors, and limited luciferase expression was observed. Higher and longer levels of expression were observed with the RCN-luc construct. When given IM, luciferase expression was limited to the site of injection, while ON exposure led to initial expression in the oral cavity, often followed by secondary replication at another location, likely the gastric mucosa or gastric associated lymphatic tissue. Viral DNA was detected in oral swabs up to 7 and 9 days post infection (dpi) for MVA and RCN, respectively. While no live virus was detected in oral swabs from MVA-infected bats, titers up to 3.88 x 104 PFU/ml were recovered from oral swabs of RCN-infected bats. Viral DNA was also detected in fecal samples from two bats inoculated IM with RCN, but no live virus was recovered. Finally, we examined the immunogenicity of a RCN based rabies vaccine (RCN-G) following ON administration. Significant rabies neutralizing antibody titers were detected in the serum of immunized bats using the rapid fluorescence focus inhibition test (RFFIT). These studies highlight the safety and immunogenicity of attenuated poxviruses and their potential use as vaccine vectors in bats.

  12. Avipoxviruses: infection biology and their use as vaccine vectors.

    Science.gov (United States)

    Weli, Simon C; Tryland, Morten

    2011-02-03

    Avipoxviruses (APVs) belong to the Chordopoxvirinae subfamily of the Poxviridae family. APVs are distributed worldwide and cause disease in domestic, pet and wild birds of many species. APVs are transmitted by aerosols and biting insects, particularly mosquitoes and arthropods and are usually named after the bird species from which they were originally isolated. The virus species Fowlpox virus (FWPV) causes disease in poultry and associated mortality is usually low, but in flocks under stress (other diseases, high production) mortality can reach up to 50%. APVs are also major players in viral vaccine vector development for diseases in human and veterinary medicine. Abortive infection in mammalian cells (no production of progeny viruses) and their ability to accommodate multiple gene inserts are some of the characteristics that make APVs promising vaccine vectors. Although abortive infection in mammalian cells conceivably represents a major vaccine bio-safety advantage, molecular mechanisms restricting APVs to certain hosts are not yet fully understood. This review summarizes the current knowledge relating to APVs, including classification, morphogenesis, host-virus interactions, diagnostics and disease, and also highlights the use of APVs as recombinant vaccine vectors.

  13. Avipoxviruses: infection biology and their use as vaccine vectors

    Directory of Open Access Journals (Sweden)

    Tryland Morten

    2011-02-01

    Full Text Available Abstract Avipoxviruses (APVs belong to the Chordopoxvirinae subfamily of the Poxviridae family. APVs are distributed worldwide and cause disease in domestic, pet and wild birds of many species. APVs are transmitted by aerosols and biting insects, particularly mosquitoes and arthropods and are usually named after the bird species from which they were originally isolated. The virus species Fowlpox virus (FWPV causes disease in poultry and associated mortality is usually low, but in flocks under stress (other diseases, high production mortality can reach up to 50%. APVs are also major players in viral vaccine vector development for diseases in human and veterinary medicine. Abortive infection in mammalian cells (no production of progeny viruses and their ability to accommodate multiple gene inserts are some of the characteristics that make APVs promising vaccine vectors. Although abortive infection in mammalian cells conceivably represents a major vaccine bio-safety advantage, molecular mechanisms restricting APVs to certain hosts are not yet fully understood. This review summarizes the current knowledge relating to APVs, including classification, morphogenesis, host-virus interactions, diagnostics and disease, and also highlights the use of APVs as recombinant vaccine vectors.

  14. Progress on adenovirus-vectored universal influenza vaccines

    OpenAIRE

    Xiang, Kui; Ying, Guan; Yan, Zhou; Shanshan, Yan; Lei, Zhang; Hongjun, Li; Maosheng, Sun

    2015-01-01

    Influenza virus (IFV) infection causes serious health problems and heavy financial burdens each year worldwide. The classical inactivated influenza virus vaccine (IIVV) and live attenuated influenza vaccine (LAIV) must be updated regularly to match the new strains that evolve due to antigenic drift and antigenic shift. However, with the discovery of broadly neutralizing antibodies that recognize conserved antigens, and the CD8+ T cell responses targeting viral internal proteins nucleoprotein ...

  15. A novel alphavirus replicon-vectored vaccine delivered by adenovirus induces sterile immunity against classical swine fever.

    Science.gov (United States)

    Sun, Yuan; Li, Hong-Yu; Tian, Da-Yong; Han, Qiu-Ying; Zhang, Xin; Li, Na; Qiu, Hua-Ji

    2011-10-26

    Low efficacy of gene-based vaccines due to inefficient gene delivery and expression has been major bottleneck of their applications. Efforts have been made to improve the efficacy, such as gene gun and electroporation, but the strategies are difficult to put into practical use. In this study, we developed and evaluated an adenovirus-delivered, alphavirus replicon-vectored vaccine (chimeric vector-based vaccine) expressing the E2 gene of classical swine fever virus (CSFV) (rAdV-SFV-E2). Rabbits immunized with rAdV-SFV-E2 developed CSFV-specific antibodies as early as 9 days and as long as 189 days and completely protected from challenge with C-strain. Pigs immunized with rAdV-SFV-E2 (n=5) developed robust humoral and cell-mediated responses to CSFV and were completely protected from subsequent lethal CSFV infection clinically and virologically. The level of immunity and protection induced by rAdV-SFV-E2 was comparable to that provided by the currently used live attenuated vaccine, C-strain. In contrast, both the conventional alphavirus replicon-vectored vaccine pSFV1CS-E2 and conventional adenovirus-vectored vaccine rAdV-E2 provided incomplete protection. The chimeric vector-based vaccine represents the first gene-based vaccine that is able to confer sterile immunity and complete protection against CSFV. The new-concept vaccination strategy may also be valuable in vaccine development against other pathogens. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Trial watch: Naked and vectored DNA-based anticancer vaccines.

    Science.gov (United States)

    Bloy, Norma; Buqué, Aitziber; Aranda, Fernando; Castoldi, Francesca; Eggermont, Alexander; Cremer, Isabelle; Sautès-Fridman, Catherine; Fucikova, Jitka; Galon, Jérôme; Spisek, Radek; Tartour, Eric; Zitvogel, Laurence; Kroemer, Guido; Galluzzi, Lorenzo

    2015-05-01

    One type of anticancer vaccine relies on the administration of DNA constructs encoding one or multiple tumor-associated antigens (TAAs). The ultimate objective of these preparations, which can be naked or vectored by non-pathogenic viruses, bacteria or yeast cells, is to drive the synthesis of TAAs in the context of an immunostimulatory milieu, resulting in the (re-)elicitation of a tumor-targeting immune response. In spite of encouraging preclinical results, the clinical efficacy of DNA-based vaccines employed as standalone immunotherapeutic interventions in cancer patients appears to be limited. Thus, efforts are currently being devoted to the development of combinatorial regimens that allow DNA-based anticancer vaccines to elicit clinically relevant immune responses. Here, we discuss recent advances in the preclinical and clinical development of this therapeutic paradigm.

  17. Vector Development for the Expression of Foreign Proteins in the Vaccine Strain Brucella abortus S19

    Science.gov (United States)

    Comerci, Diego J.; Pollevick, Guido D.; Vigliocco, Ana M.; Frasch, Alberto C. C.; Ugalde, Rodolfo A.

    1998-01-01

    A vector for the expression of foreign antigens in the vaccine strain Brucella abortus S19 was developed by using a DNA fragment containing the regulatory sequences and the signal peptide of the Brucella bcsp31 gene. This fragment was cloned in broad-host-range plasmid pBBR4MCS, resulting in plasmid pBEV. As a reporter protein, a repetitive antigen of Trypanosoma cruzi was used. The recombinant fusion protein is stably expressed and secreted into the Brucella periplasmic space, inducing a good antibody response against the T. cruzi antigen. The expression of the repetitive antigen in Brucella neither altered its growth pattern nor generated a toxic or lethal effect during experimental infection. The application of this strategy for the generation of live recombinant vaccines and the tagging of B. abortus S19 vaccine is discussed. This is the first time that a recombinant protein has been expressed in the periplasm of brucellae. PMID:9673273

  18. Percutaneous Vaccination as an Effective Method of Delivery of MVA and MVA-Vectored Vaccines.

    Directory of Open Access Journals (Sweden)

    Clement A Meseda

    Full Text Available The robustness of immune responses to an antigen could be dictated by the route of vaccine inoculation. Traditional smallpox vaccines, essentially vaccinia virus strains, that were used in the eradication of smallpox were administered by percutaneous inoculation (skin scarification. The modified vaccinia virus Ankara is licensed as a smallpox vaccine in Europe and Canada and currently undergoing clinical development in the United States. MVA is also being investigated as a vector for the delivery of heterologous genes for prophylactic or therapeutic immunization. Since MVA is replication-deficient, MVA and MVA-vectored vaccines are often inoculated through the intramuscular, intradermal or subcutaneous routes. Vaccine inoculation via the intramuscular, intradermal or subcutaneous routes requires the use of injection needles, and an estimated 10 to 20% of the population of the United States has needle phobia. Following an observation in our laboratory that a replication-deficient recombinant vaccinia virus derived from the New York City Board of Health strain elicited protective immune responses in a mouse model upon inoculation by tail scarification, we investigated whether MVA and MVA recombinants can elicit protective responses following percutaneous administration in mouse models. Our data suggest that MVA administered by percutaneous inoculation, elicited vaccinia-specific antibody responses, and protected mice from lethal vaccinia virus challenge, at levels comparable to or better than subcutaneous or intramuscular inoculation. High titers of specific neutralizing antibodies were elicited in mice inoculated with a recombinant MVA expressing the herpes simplex type 2 glycoprotein D after scarification. Similarly, a recombinant MVA expressing the hemagglutinin of attenuated influenza virus rgA/Viet Nam/1203/2004 (H5N1 elicited protective immune responses when administered at low doses by scarification. Taken together, our data suggest that

  19. Percutaneous Vaccination as an Effective Method of Delivery of MVA and MVA-Vectored Vaccines.

    Science.gov (United States)

    Meseda, Clement A; Atukorale, Vajini; Kuhn, Jordan; Schmeisser, Falko; Weir, Jerry P

    2016-01-01

    The robustness of immune responses to an antigen could be dictated by the route of vaccine inoculation. Traditional smallpox vaccines, essentially vaccinia virus strains, that were used in the eradication of smallpox were administered by percutaneous inoculation (skin scarification). The modified vaccinia virus Ankara is licensed as a smallpox vaccine in Europe and Canada and currently undergoing clinical development in the United States. MVA is also being investigated as a vector for the delivery of heterologous genes for prophylactic or therapeutic immunization. Since MVA is replication-deficient, MVA and MVA-vectored vaccines are often inoculated through the intramuscular, intradermal or subcutaneous routes. Vaccine inoculation via the intramuscular, intradermal or subcutaneous routes requires the use of injection needles, and an estimated 10 to 20% of the population of the United States has needle phobia. Following an observation in our laboratory that a replication-deficient recombinant vaccinia virus derived from the New York City Board of Health strain elicited protective immune responses in a mouse model upon inoculation by tail scarification, we investigated whether MVA and MVA recombinants can elicit protective responses following percutaneous administration in mouse models. Our data suggest that MVA administered by percutaneous inoculation, elicited vaccinia-specific antibody responses, and protected mice from lethal vaccinia virus challenge, at levels comparable to or better than subcutaneous or intramuscular inoculation. High titers of specific neutralizing antibodies were elicited in mice inoculated with a recombinant MVA expressing the herpes simplex type 2 glycoprotein D after scarification. Similarly, a recombinant MVA expressing the hemagglutinin of attenuated influenza virus rgA/Viet Nam/1203/2004 (H5N1) elicited protective immune responses when administered at low doses by scarification. Taken together, our data suggest that MVA and MVA-vectored

  20. Live Attenuated Tularemia Vaccines for Protection Against Respiratory Challenge With Virulent F. tularensis subsp. tularensis

    Science.gov (United States)

    Jia, Qingmei; Horwitz, Marcus A.

    2018-01-01

    Francisella tularensis is the causative agent of tularemia and a Tier I bioterrorism agent. In the 1900s, several vaccines were developed against tularemia including the killed “Foshay” vaccine, subunit vaccines comprising F. tularensis protein(s) or lipoproteins(s) in an adjuvant formulation, and the F. tularensis Live Vaccine Strain (LVS); none were licensed in the U.S.A. or European Union. The LVS vaccine retains toxicity in humans and animals—especially mice—but has demonstrated efficacy in humans, and thus serves as the current gold standard for vaccine efficacy studies. The U.S.A. 2001 anthrax bioterrorism attack spawned renewed interest in vaccines against potential biowarfare agents including F. tularensis. Since live attenuated—but not killed or subunit—vaccines have shown promising efficacy and since vaccine efficacy against respiratory challenge with less virulent subspecies holarctica or F. novicida, or against non-respiratory challenge with virulent subsp. tularensis (Type A) does not reliably predict vaccine efficacy against respiratory challenge with virulent subsp. tularensis, the route of transmission and species of greatest concern in a bioterrorist attack, in this review, we focus on live attenuated tularemia vaccine candidates tested against respiratory challenge with virulent Type A strains, including homologous vaccines derived from mutants of subsp. holarctica, F. novicida, and subsp. tularensis, and heterologous vaccines developed using viral or bacterial vectors to express F. tularensis immunoprotective antigens. We compare the virulence and efficacy of these vaccine candidates with that of LVS and discuss factors that can significantly impact the development and evaluation of live attenuated tularemia vaccines. Several vaccines meet what we would consider the minimum criteria for vaccines to go forward into clinical development—safety greater than LVS and efficacy at least as great as LVS, and of these, several meet the

  1. [The gentic principles for the design of live Salmonella vaccines].

    Science.gov (United States)

    Petrovskaia, V G; Marakusha, B I; Bondarenko, V M

    1996-01-01

    The presently known methods of obtaining Salmonella vaccine strains are characterized, their advantages and drawbacks are noted. Great importance of the genetic safety of Salmonella attenuated strains to be controlled is emphasized, taking into account that they are also used as carrier strains for obtaining hybrid and gene-engineering (vector) vaccines carrying immunogenicity factors of other species of pathogenic microorganisms.

  2. Monitoring of Antibodies Titre Against Canine Distemper Virus in Ferrets Vaccinated with a Live Modified Vaccine

    OpenAIRE

    L. Pavlačík; V. Celer, Jr.; V. Kajerová; V. Jekl; Z. Knotek; I. Literák

    2007-01-01

    A group of five ferrets vaccinated against the canine distemper virus (CDV) was evaluated as to the onset of anti-CDV antibody production and the serum levels of the animals were monitored for one year. The ferrets were immunized with a live attenuated vaccine. The vaccination pattern was as follows: primary vaccination at the age of 6 weeks, fi rst revaccination at 30 days after primary vaccination, and second revaccination after another 30 days. Blood samples were taken prior to primary vac...

  3. Vector choice determines immunogenicity and potency of genetic vaccines against Angola Marburg virus in nonhuman primates

    NARCIS (Netherlands)

    Geisbert, Thomas W.; Bailey, Michael; Geisbert, Joan B.; Asiedu, Clement; Roederer, Mario; Grazia-Pau, Maria; Custers, Jerome; Jahrling, Peter; Goudsmit, Jaap; Koup, Richard; Sullivan, Nancy J.

    2010-01-01

    The immunogenicity and durability of genetic vaccines are influenced by the composition of gene inserts and choice of delivery vector. DNA vectors are a promising vaccine approach showing efficacy when combined in prime-boost regimens with recombinant protein or viral vectors, but they have shown

  4. A safe and efficient BCG vectored vaccine to prevent the disease caused by the human Respiratory Syncytial Virus.

    Science.gov (United States)

    Rey-Jurado, Emma; Soto, Jorge; Gálvez, Nicolás; Kalergis, Alexis M

    2017-09-02

    The human Respiratory Syncytial Virus (hRSV) causes lower respiratory tract infections including pneumonia and bronchiolitis. Such infections also cause a large number of hospitalizations and affects mainly newborns, young children and the elderly worldwide. Symptoms associated with hRSV infection are due to an exacerbated immune response characterized by low levels of IFN-γ, recruitment of neutrophils and eosinophils to the site of infection and lung damage. Although hRSV is a major health problem, no vaccines are currently available. Different immunization approaches have been developed to achieve a vaccine that activates the immune system, without triggering an unbalanced inflammation. These approaches include live attenuated vaccine, DNA or proteins technologies, and the use of vectors to express proteins of the virus. In this review, we discuss the host immune response to hRSV and the immunological mechanisms underlying an effective and safe BCG vectored vaccine against hRSV.

  5. Live virus vaccines based on a yellow fever vaccine backbone: standardized template with key considerations for a risk/benefit assessment.

    Science.gov (United States)

    Monath, Thomas P; Seligman, Stephen J; Robertson, James S; Guy, Bruno; Hayes, Edward B; Condit, Richard C; Excler, Jean Louis; Mac, Lisa Marie; Carbery, Baevin; Chen, Robert T

    2015-01-01

    The Brighton Collaboration Viral Vector Vaccines Safety Working Group (V3SWG) was formed to evaluate the safety of live, recombinant viral vaccines incorporating genes from heterologous viruses inserted into the backbone of another virus (so-called "chimeric virus vaccines"). Many viral vector vaccines are in advanced clinical trials. The first such vaccine to be approved for marketing (to date in Australia, Thailand, Malaysia, and the Philippines) is a vaccine against the flavivirus, Japanese encephalitis (JE), which employs a licensed vaccine (yellow fever 17D) as a vector. In this vaccine, two envelope proteins (prM-E) of YF 17D virus were exchanged for the corresponding genes of JE virus, with additional attenuating mutations incorporated into the JE gene inserts. Similar vaccines have been constructed by inserting prM-E genes of dengue and West Nile into YF 17D virus and are in late stage clinical studies. The dengue vaccine is, however, more complex in that it requires a mixture of four live vectors each expressing one of the four dengue serotypes. This vaccine has been evaluated in multiple clinical trials. No significant safety concerns have been found. The Phase 3 trials met their endpoints in terms of overall reduction of confirmed dengue fever, and, most importantly a significant reduction in severe dengue and hospitalization due to dengue. However, based on results that have been published so far, efficacy in preventing serotype 2 infection is less than that for the other three serotypes. In the development of these chimeric vaccines, an important series of comparative studies of safety and efficacy were made using the parental YF 17D vaccine virus as a benchmark. In this paper, we use a standardized template describing the key characteristics of the novel flavivirus vaccine vectors, in comparison to the parental YF 17D vaccine. The template facilitates scientific discourse among key stakeholders by increasing the transparency and comparability of

  6. [A case of orchitis following vaccination with freeze-dried live attenuated mumps vaccine].

    Science.gov (United States)

    Suzuki, Masayasu; Takizawa, Akitoshi; Furuta, Akira; Yanada, Shuichi; Iwamuro, Shinya; Tashiro, Kazuya

    2002-05-01

    In Japan, freeze-dried live attenuated mumps vaccine has been used optionally since 1981. The effectiveness of mumps vaccination has been established by worldwide research since 1971. On the other hand, because of it's live activity several untoward effects have been reported. Vaccination-related mumps orchitis is a rare adverse effect of mumps vaccine. Only 9 cases of vaccination-related mumps orchitis have been reported in Japan. We describe a case of orchitis following mumps vaccination in adolescence. A 16 years-old male has admitted because of acute orchitis with high fever and painful swelling of right testis. The patient had received vaccination with freeze-dried live attenuated mumps vaccine 16 days before admission. After admission, the bed-rest had completely relieved the symptoms on 6th hospital day. The impaired testis has maintained normal size and consistency 6 months after discharge.

  7. Long-lived tissue resident HIV-1 specific memory CD8+ T cells are generated by skin immunization with live virus vectored microneedle arrays

    OpenAIRE

    Zaric, Marija; Becker, Pablo Daniel; Hervouet, Catherine; Kalcheva, Petya; Ibarzo Yus, Barbara; Cocita, Clement; O'Neill, Lauren Alexandra; Kwon, Sung-Yun; Klavinskis, Linda Sylvia

    2017-01-01

    The generation of tissue resident memory (TRM) cells at the body surfaces to provide a front line defence against invading pathogens represents an important goal in vaccine development for a wide variety of pathogens. It has been widely assumed that local vaccine delivery to the mucosae is necessary to achieve that aim. Here we characterise a novel micro-needle array (MA) delivery system fabricated to deliver a live recombinant human adenovirus type 5 vaccine vector (AdHu5) encoding HIV-1 gag...

  8. Live Virus Vaccines Based on a Yellow Fever Vaccine Backbone: Standardized Template with Key Considerations for a Risk/Benefit Assessment*

    Science.gov (United States)

    Monath, Thomas P.; Seligman, Stephen J.; Robertson, James S.; Guy, Bruno; Hayes, Edward B.; Condit, Richard C.; Excler, Jean Louis; Mac, Lisa Marie; Carbery, Baevin; Chen, Robert T

    2015-01-01

    The Brighton Collaboration Viral Vector Vaccines Safety Working Group (V3SWG) was formed to evaluate the safety of live, recombinant viral vaccines incorporating genes from heterologous viruses inserted into the backbone of another virus (so-called “chimeric virus vaccines”). Many viral vector vaccines are in advanced clinical trials. The first such vaccine to be approved for marketing (to date in Australia, Thailand, Malaysia, and the Philippines) is a vaccine against the flavivirus Japanese encephalitis (JE), which employs a licensed vaccine (yellow fever 17D) as a vector. In this vaccine, two envelope proteins (prM-E) of YF 17D virus were replaced by the corresponding genes of JE virus, with additional attenuating mutations incorporated into the JE gene inserts. Similar vaccines have been constructed by inserting prM-E genes of dengue and West Nile into YF 17D virus and are in late stage clinical studies. The dengue vaccine is, however, more complex in that it requires a mixture of four live vectors each expressing one of the four dengue serotypes. This vaccine has been evaluated in multiple clinical trials. No significant safety concerns have been found. The Phase 3 trials met their endpoints in terms of overall reduction of confirmed dengue fever, and, most importantly a significant reduction in severe dengue and hospitalization due to dengue. However, based on results that have been published so far, efficacy in preventing serotype 2 infection is less than that for the other three serotypes. In the development of these chimeric vaccines, an important series of comparative studies of safety and efficacy were made using the parental YF 17D vaccine virus as a benchmark. In this paper, we use a standardized template describing the key characteristics of the novel flavivirus vaccine vectors, in comparison to the parental YF 17D vaccine. The template facilitates scientific discourse among key stakeholders by increasing the transparency and comparability of

  9. Priming T-cell responses with recombinant measles vaccine vector in a heterologous prime-boost setting in non-human primates

    OpenAIRE

    Bolton, Diane L.; Santra, Sampa; Swett, Cindy; Custers, Jerome; Song, Kaimei; Balachandran, Harikrishnan; Kozlowski, Pamela A.; Letvin, Norman; Roederer, Mario; Radošević, Katarina

    2012-01-01

    Licensed live attenuated virus vaccines capable of expressing transgenes from other pathogens have the potential to reduce the number of childhood immunizations by eliciting robust immunity to multiple pathogens simultaneously. Recombinant attenuated measles virus (rMV) derived from the Edmonston Zagreb vaccine strain was engineered to express simian immunodeficiency virus (SIV) Gag protein for the purpose of evaluating the immunogenicity of rMV as a vaccine vector in rhesus macaques. rMV-Gag...

  10. Conditional live virus as a novel approach towards a safe live attenuated HIV vaccine

    NARCIS (Netherlands)

    Das, Atze T.; Zhou, Xue; Vink, Monique; Klaver, Bep; Berkhout, Ben

    2002-01-01

    To control the worldwide spread of HIV, a safe and effective prophylactic vaccine is urgently needed. Studies with the simian immunodeficiency virus demonstrated that a live attenuated virus can be effective as a vaccine, but serious concerns about the safety of such a vaccine virus have arisen. We

  11. Live porcine reproductive and respiratory syndrome virus vaccines: Current status and future direction.

    Science.gov (United States)

    Renukaradhya, Gourapura J; Meng, Xiang-Jin; Calvert, Jay G; Roof, Michael; Lager, Kelly M

    2015-08-07

    Porcine reproductive and respiratory syndrome (PRRS) caused by PRRS virus (PRRSV) was reported in the late 1980s. PRRS still is a huge economic concern to the global pig industry with a current annual loss estimated at one billion US dollars in North America alone. It has been 20 years since the first modified live-attenuated PRRSV vaccine (PRRSV-MLV) became commercially available. PRRSV-MLVs provide homologous protection and help in reducing shedding of heterologous viruses, but they do not completely protect pigs against heterologous field strains. There have been many advances in understanding the biology and ecology of PRRSV; however, the complexities of virus-host interaction and PRRSV vaccinology are not yet completely understood leaving a significant gap for improving breadth of immunity against diverse PRRS isolates. This review provides insights on immunization efforts using infectious PRRSV-based vaccines since the 1990s, beginning with live PRRSV immunization, development and commercialization of PRRSV-MLV, and strategies to overcome the deficiencies of PRRSV-MLV through use of replicating viral vectors expressing multiple PRRSV membrane proteins. Finally, powerful reverse genetics systems (infectious cDNA clones) generated from more than 20 PRRSV isolates of both genotypes 1 and 2 viruses have provided a great resource for exploring many innovative strategies to improve the safety and cross-protective efficacy of live PRRSV vaccines. Examples include vaccines with diminished ability to down-regulate the immune system, positive and negative marker vaccines, multivalent vaccines incorporating antigens from other porcine pathogens, vaccines that carry their own cytokine adjuvants, and chimeric vaccine viruses with the potential for broad cross-protection against heterologous strains. To combat this devastating pig disease in the future, evaluation and commercialization of such improved live PRRSV vaccines is a shared goal among PRRSV researchers, pork

  12. Heterologous prime-boost immunization of Newcastle disease virus vectored vaccines protected broiler chickens against highly pathogenic avian influenza and Newcastle disease viruses.

    Science.gov (United States)

    Kim, Shin-Hee; Samal, Siba K

    2017-07-24

    Avian Influenza virus (AIV) is an important pathogen for both human and animal health. There is a great need to develop a safe and effective vaccine for AI infections in the field. Live-attenuated Newcastle disease virus (NDV) vectored AI vaccines have shown to be effective, but preexisting antibodies to the vaccine vector can affect the protective efficacy of the vaccine in the field. To improve the efficacy of AI vaccine, we generated a novel vectored vaccine by using a chimeric NDV vector that is serologically distant from NDV. In this study, the protective efficacy of our vaccines was evaluated by using H5N1 highly pathogenic avian influenza virus (HPAIV) strain A/Vietnam/1203/2004, a prototype strain for vaccine development. The vaccine viruses were three chimeric NDVs expressing the hemagglutinin (HA) protein in combination with the neuraminidase (NA) protein, matrix 1 protein, or nonstructural 1 protein. Comparison of their protective efficacy between a single and prime-boost immunizations indicated that prime immunization of 1-day-old SPF chicks with our vaccine viruses followed by boosting with the conventional NDV vector strain LaSota expressing the HA protein provided complete protection of chickens against mortality, clinical signs and virus shedding. Further verification of our heterologous prime-boost immunization using commercial broiler chickens suggested that a sequential immunization of chickens with chimeric NDV vector expressing the HA and NA proteins following the boost with NDV vector expressing the HA protein can be a promising strategy for the field vaccination against HPAIVs and against highly virulent NDVs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Use of a vectored vaccine against infectious bursal disease of chickens in the face of high-titred maternally derived antibody.

    Science.gov (United States)

    Bublot, M; Pritchard, N; Le Gros, F-X; Goutebroze, S

    2007-07-01

    Interference by maternally derived antibody (MDA) is a major problem for the vaccination of young chickens against infectious bursal disease (IBD). The choice of the timing of vaccination and of the type (degree of attenuation) of modified-live vaccine (MLV) to use is often difficult. An IBD vectored vaccine (vHVT13), in which turkey herpesvirus (HVT) is used as the vector, was recently developed. This vaccine is administered once at the hatchery, either in ovo or by the subcutaneous route, to 1-day-old chicks at a time when MDA is maximal. In terms of safety, the vHVT13 vaccine had negligible impact on the bursa of Fabricius when compared with classical IBD MLV. Vaccination and challenge studies demonstrated that this vaccine is able to protect chickens against various IBD virus (IBDV) challenge strains including very virulent, classical, and USA variant IBDV, despite the presence of high-titred IBD MDA at the time of vaccination. These data show that the vector vaccine combines a safety and efficacy profile that cannot be achieved with classical IBD vaccines.

  14. Live attenuated hepatitis A vaccines developed in China

    Science.gov (United States)

    Xu, Zhi-Yi; Wang, Xuan-Yi

    2014-01-01

    Two live, attenuated hepatitis A vaccines, H2 and LA-1 virus strains, were developed through serial passages of the viruses in cell cultures at 32 °C and 35 °C respectively. Both vaccines were safe and immunogenic, providing protection against clinical hepatitis A in 95% of the vaccinees, with a single dose by subcutaneous injection. The vaccine recipients were not protected from asymptomatic, subclinical hepatitis A virus (HAV) infection, which induced a similar antibody response as for unvaccinated subjects. A second dose caused anamnestic response and can be used for boosting. Oral immunization of human with H2 vaccine or of marmoset with LA-1 vaccine failed, and no evidence was found for person-to-person transmission of H2 strain or for marmoset-to-marmoset transmission of LA-1 strain by close contact. H2 strain was genetically stable when passaged in marmosets, humans or cell cultures at 37 °C; 3 consecutive passages of the virus in marmosets did not cause virulence mutation. The live vaccines offer the benefits of low cost, single dose injection, long- term protection, and increased duration of immunity through subclinical infection. Improved sanitation and administration of 150 million doses of the live vaccines to children had led to a 90% reduction in the annual national incidence rate of hepatitis A in China during the 16-year period, from 1991 to 2006. Hepatitis A (HA) immunization with both live and inactivated HA vaccines was implemented in the national routine childhood immunization program in 2008 and around 92% of the 16 million annual births received the affordable live, attenuated vaccines at 18 months of age. Near elimination of the disease was achieved in a county of China for 14 years following introduction of the H2 live vaccine into the Expanded Immunization Program (EPI) in 1992. PMID:24280971

  15. Live Attenuated Yellow Fever 17D Vaccine: A Legacy Vaccine Still Controlling Outbreaks In Modern Day.

    Science.gov (United States)

    Collins, Natalie D; Barrett, Alan D T

    2017-03-01

    Live attenuated 17D vaccine is considered one of the safest and efficacious vaccines developed to date. This review highlights what is known and the gaps in knowledge of vaccine-induced protective immunity. Recently, the World Health Organization modifying its guidance from 10-year booster doses to one dose gives lifelong protection in most populations. Nonetheless, there are some data suggesting immunity, though protective, may wane over time in certain populations and more research is needed to address this question. Despite having an effective vaccine to control yellow fever, vaccine shortages were identified during outbreaks in 2016, eventuating the use of a fractional-dosing campaign in the Democratic Republic of the Congo. Limited studies hinder identification of the underlying mechanism(s) of vaccine longevity; however, concurrent outbreaks during 2016 provide an opportunity to evaluate vaccine immunity following fractional dosing and insights into vaccine longevity in populations where there is limited information.

  16. Evolution of Live-Attenuated HIV Vaccines

    NARCIS (Netherlands)

    Berkhout, Ben

    2011-01-01

    Despite intensive research since the viral pathogen was discovered some 25 years ago, not much progress has been reported on the development of a safe vaccine that protects against human immunodeficiency virus type 1. A vaccine approach that has been abandoned because its safety cannot be guaranteed

  17. A novel live-attenuated vaccine candidate for mayaro Fever.

    Directory of Open Access Journals (Sweden)

    William J Weise

    2014-08-01

    Full Text Available Mayaro virus (MAYV is an emerging, mosquito-borne alphavirus that causes a dengue-like illness in many regions of South America, and which has the potential to urbanize. Because no specific treatment or vaccine is available for MAYV infection, we capitalized on an IRES-based approach to develop a live-attenuated MAYV vaccine candidate. Testing in infant, immunocompetent as well as interferon receptor-deficient mice demonstrated a high degree of attenuation, strong induction of neutralizing antibodies, and efficacy against lethal challenge. This vaccine strain was also unable to infect mosquito cells, a major safety feature for a live vaccine derived from a mosquito-borne virus. Further preclinical development of this vaccine candidate is warranted to protect against this important emerging disease.

  18. Assessment of Lactobacillus gasseri as a candidate oral vaccine vector.

    Science.gov (United States)

    Stoeker, Laura; Nordone, Shila; Gunderson, Sara; Zhang, Lin; Kajikawa, Akinobu; LaVoy, Alora; Miller, Michael; Klaenhammer, Todd R; Dean, Gregg A

    2011-11-01

    Lactobacillus species are commensal bacteria that have long been recognized as probiotic microbes and are generally regarded as safe (GRAS) for human consumption. We have investigated the use of L. gasseri as a vaccine vector for oral immunization against mucosal pathogens. Recent research has shown that the immune response to different lactobacilli can vary widely depending on the species or subspecies of Lactobacillus being studied. While some lactobacilli seem to induce oral tolerance, others induce an adaptive immune response. This study characterized the systemic and mucosal immune response to wild-type and genetically modified L. gasseri. L. gasseri primarily activates TLR2/6, with additional activation through the TLR2 homodimer. To expand the Toll-like receptor (TLR) activation profile of L. gasseri and the immunogenicity of the vector, a plasmid containing fliC, the gene encoding bacterial flagellin, was introduced which resulted in the strong activation of TLR5. The treatment of human myeloid dendritic cells with recombinant lactobacilli expressing flagellin triggered phenotypic maturation and the release of proinflammatory cytokines. In contrast, bacterial treatment also resulted in a statistically significant increase in IL-10 production. In vivo studies established that treatment with L. gasseri led to a diversification of B-cell populations in the lamina propria of the murine colon. Furthermore, treatment with genetically modified L. gasseri led to a significant decrease in the percentage of FoxP3(+) colonic lymphocytes. Taken together, these data clarify the interaction of L. gasseri with the host immune system and support further investigation of the in vivo immunogenicity of L. gasseri expressing both flagellin and candidate vaccine antigens.

  19. Vector-transmitted disease vaccines: targeting salivary proteins in transmission (SPIT).

    Science.gov (United States)

    McDowell, Mary Ann

    2015-08-01

    More than half the population of the world is at risk for morbidity and mortality from vector-transmitted diseases, and emerging vector-transmitted infections are threatening new populations. Rising insecticide resistance and lack of efficacious vaccines highlight the need for novel control measures. One such approach is targeting the vector-host interface by incorporating vector salivary proteins in anti-pathogen vaccines. Debate remains about whether vector saliva exposure exacerbates or protects against more severe clinical manifestations, induces immunity through natural exposure or extends to all vector species and associated pathogens. Nevertheless, exploiting this unique biology holds promise as a viable strategy for the development of vaccines against vector-transmitted diseases. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Mucosal vaccination with heterologous viral vectored vaccine targeting subdominant SIV accessory antigens strongly inhibits early viral replication

    DEFF Research Database (Denmark)

    Xu, Huanbin; Andersson, Anne-Marie Carola; Ragonnaud, Emeline

    2017-01-01

    Conventional HIV T cell vaccine strategies have not been successful in containing acute peak viremia, nor in providing long-term control. We immunized rhesus macaques intramuscularly and rectally using a heterologous adenovirus vectored SIV vaccine regimen encoding normally weakly immunogenic tat...

  1. A Respiratory Syncytial Virus Vaccine Vectored by a Stable Chimeric and Replication-Deficient Sendai Virus Protects Mice without Inducing Enhanced Disease.

    Science.gov (United States)

    Wiegand, Marian Alexander; Gori-Savellini, Gianni; Gandolfo, Claudia; Papa, Guido; Kaufmann, Christine; Felder, Eva; Ginori, Alessandro; Disanto, Maria Giulia; Spina, Donatella; Cusi, Maria Grazia

    2017-05-15

    Respiratory syncytial virus (RSV) is a major cause of severe respiratory infections in children and elderly people, and no marketed vaccine exists. In this study, we generated and analyzed a subunit vaccine against RSV based on a novel genome replication-deficient Sendai virus (SeV) vector. We inserted the RSV F protein, known to be a genetically stable antigen, into our vector in a specific way to optimize the vaccine features. By exchanging the ectodomain of the SeV F protein for its counterpart from RSV, we created a chimeric vectored vaccine that contains the RSV F protein as an essential structural component. In this way, the antigen is actively expressed on the surfaces of vaccine particles in its prefusion conformation, and as recently reported for other vectored vaccines, the occurrence of silencing mutations of the transgene in the vaccine genome can be prevented. In addition, its active gene expression contributes to further stimulation of the immune response. In order to understand the best route of immunization, we compared vaccine efficacies after intranasal (i.n.) or intramuscular (i.m.) immunization of BALB/c mice. Via both routes, substantial RSV-specific immune responses were induced, consisting of serum IgG and neutralizing antibodies, as well as cytotoxic T cells. Moreover, i.n. immunization was also able to stimulate specific mucosal IgA in the upper and lower respiratory tract. In virus challenge experiments, animals were protected against RSV infection after both i.n. and i.m. immunization without inducing vaccine-enhanced disease. Above all, the replication-deficient SeV appeared to be safe and well tolerated. IMPORTANCE Respiratory syncytial virus (RSV) is a major cause of respiratory diseases in young children and elderly people worldwide. There is a great demand for a licensed vaccine. Promising existing vaccine approaches based on live-attenuated vaccines or viral vectors have suffered from unforeseen drawbacks related to immunogenicity

  2. Influenza viral vectors expressing the Brucella OMP16 or L7/L12 proteins as vaccines against B. abortus infection.

    Science.gov (United States)

    Tabynov, Kaissar; Sansyzbay, Abylai; Kydyrbayev, Zhailaubay; Yespembetov, Bolat; Ryskeldinova, Sholpan; Zinina, Nadezhda; Assanzhanova, Nurika; Sultankulova, Kulaisan; Sandybayev, Nurlan; Khairullin, Berik; Kuznetsova, Irina; Ferko, Boris; Egorov, Andrej

    2014-04-10

    a commercial live B. abortus 19 vaccine. Thus, influenza vectors expressing Brucella protective antigens can be developed as novel influenza vectored vaccine against B. abortus infection.

  3. Yellow fever live attenuated vaccine: A very successful live attenuated vaccine but still we have problems controlling the disease.

    Science.gov (United States)

    Barrett, Alan D T

    2017-10-20

    Yellow fever (YF) is regarded as the original hemorrhagic fever and has been a major public health problem for at least 250years. A very effective live attenuated vaccine, strain 17D, was developed in the 1930s and this has proved critical in the control of the disease. There is little doubt that without the vaccine, YF virus would be considered a biosafety level 4 pathogen. Significantly, YF is currently the only disease where an international vaccination certificate is required under the International Health Regulations. Despite having a very successful vaccine, there are occasional issues of supply and demand, such as that which occurred in Angola and Democratic Republic of Congo in 2016 when there was insufficient vaccine available. For the first time fractional dosing of the vaccine was approved on an emergency basis. Thus, continued vigilance and improvements in supply and demand are needed in the future. Copyright © 2017. Published by Elsevier Ltd.

  4. Humoral Immunity to Primary Smallpox Vaccination: Impact of Childhood versus Adult Immunization on Vaccinia Vector Vaccine Development in Military Populations.

    Directory of Open Access Journals (Sweden)

    Bonnie M Slike

    Full Text Available Modified Vaccinia virus has been shown to be a safe and immunogenic vector platform for delivery of HIV vaccines. Use of this vector is of particular importance to the military, with the implementation of a large scale smallpox vaccination campaign in 2002 in active duty and key civilian personnel in response to potential bioterrorist activities. Humoral immunity to smallpox vaccination was previously shown to be long lasting (up to 75 years and protective. However, using vaccinia-vectored vaccine delivery for other diseases on a background of anti-vector antibodies (i.e. pre-existing immunity may limit their use as a vaccine platform, especially in the military. In this pilot study, we examined the durability of vaccinia antibody responses in adult primary vaccinees in a healthy military population using a standard ELISA assay and a novel dendritic cell neutralization assay. We found binding and neutralizing antibody (NAb responses to vaccinia waned after 5-10 years in a group of 475 active duty military, born after 1972, who were vaccinated as adults with Dryvax®. These responses decreased from a geometric mean titer (GMT of 250 to baseline (30 years with a GMT of 210 (range 112-3234. This data suggests limited durability of antibody responses in adult vaccinees compared to those vaccinated in childhood and further that adult vaccinia recipients may benefit similarly from receipt of a vaccinia based vaccine as those who are vaccinia naïve. Our findings may have implications for the smallpox vaccination schedule and support the ongoing development of this promising viral vector in a military vaccination program.

  5. Infection and transmission of live recombinant Newcastle disease virus vaccines in Rock Pigeons, European House Sparrows, and Japanese Quail

    Science.gov (United States)

    In China and Mexico, engineered recombinant Newcastle disease virus (rNDV) strains are used as live vaccines for the control of Newcastle disease and as vectors to express the avian influenza virus hemagglutinin (HA) gene to control avian influenza in poultry. In this study, non-target species wer...

  6. The yellow fever 17D virus as a platform for new live attenuated vaccines.

    Science.gov (United States)

    Bonaldo, Myrna C; Sequeira, Patrícia C; Galler, Ricardo

    2014-01-01

    The live-attenuated yellow fever 17D virus is one of the most outstanding human vaccines ever developed. It induces efficacious immune responses at a low production cost with a well-established manufacture process. These advantages make the YF17D virus attractive as a vector for the development of new vaccines. At the beginning of vector development studies, YF17D was genetically manipulated to express other flavivirus prM and E proteins, components of the viral envelope. While these 17D recombinants are based on the substitution of equivalent YF17D genes, other antigens from unrelated pathogens have also been successfully expressed and delivered by recombinant YF17D viruses employing alternative strategies for genetic manipulation of the YF17D genome. Herein, we discuss these strategies in terms of possibilities of single epitope or larger sequence expression and the main properties of these replication-competent viral platforms.

  7. Immune response profiles of calves following vaccination with live BCG and inactivated Mycobacterium bovis vaccine candidates.

    Directory of Open Access Journals (Sweden)

    E M D L van der Heijden

    Full Text Available Conventional control and eradication strategies for bovine tuberculosis (BTB face tremendous difficulties in developing countries; countries with wildlife reservoirs, a complex wildlife-livestock-human interface or a lack of veterinary and veterinary public health surveillance. Vaccination of cattle and other species might in some cases provide the only suitable control strategy for BTB, while in others it may supplement existing test-and-slaughter schemes. However, the use of live BCG has several limitations and the global rise of HIV/AIDS infections has furthermore warranted the exploration of inactivated vaccine preparations. The aim of this study was to compare the immune response profiles in response to parenteral vaccination with live BCG and two inactivated vaccine candidates in cattle. Twenty-four mixed breed calves (Bos taurus aged 4-6 months, were allocated to one of four groups and vaccinated sub-cutaneously with live M. bovis BCG (Danish 1331, formalin-inactivated M. bovis BCG, heat-killed M. bovis or PBS/Montanide™ (control. Interferon-γ responsiveness and antibody production were measured prior to vaccination and at weekly intervals thereafter for twelve weeks. At nine weeks post-priming, animals were skin tested using tuberculins and MTBC specific protein cocktails and subsequently challenged through intranodular injection of live M. bovis BCG. The animals in the heat-killed M. bovis group demonstrated strong and sustained cell-mediated and humoral immune responses, significantly higher than the control group in response to vaccination, which may indicate a protective immune profile. Animals in this group showed reactivity to the skin test reagents, confirming good vaccine take. Lastly, although not statistically significant, recovery of BCG after challenge was lowest in the heat-killed M. bovis group. In conclusion, the parenteral heat-killed M. bovis vaccine proved to be clearly immunogenic in cattle in the present study

  8. 9 CFR 113.300 - General requirements for live virus vaccines.

    Science.gov (United States)

    2010-01-01

    ... vaccines. 113.300 Section 113.300 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... REQUIREMENTS Live Virus Vaccines § 113.300 General requirements for live virus vaccines. When prescribed in an applicable Standard Requirement or in the filed Outline of Production, a live virus vaccine shall meet the...

  9. A paramyxovirus-vectored intranasal vaccine against Ebola virus is immunogenic in vector-immune animals.

    Science.gov (United States)

    Yang, Lijuan; Sanchez, Anthony; Ward, Jerrold M; Murphy, Brian R; Collins, Peter L; Bukreyev, Alexander

    2008-08-01

    Ebola virus (EBOV) causes outbreaks of a highly lethal hemorrhagic fever in humans. The virus can be transmitted by direct contact as well as by aerosol and is considered a potential bioweapon. Because direct immunization of the respiratory tract should be particularly effective against infection of mucosal surfaces, we previously developed an intranasal vaccine based on replication-competent human parainfluenza virus type 3 (HPIV3) expressing EBOV glycoprotein GP (HPIV3/EboGP) and showed that it is immunogenic and protective against a high dose parenteral EBOV challenge. However, because the adult human population has considerable immunity to HPIV3, which is a common human pathogen, replication and immunogenicity of the vaccine in this population might be greatly restricted. Indeed, in the present study, replication of the vaccine in the respiratory tract of HPIV3-immune guinea pigs was found to be restricted to undetectable levels. This restriction appeared to be based on both neutralizing antibodies and cellular or other components of the immunity to HPIV3. Surprisingly, even though replication of HPIV3/EboGP was highly restricted in HPIV3-immune animals, it induced a high level of EBOV-specific antibodies that nearly equaled that obtained in HPIV3-naive animals. We also show that the previously demonstrated presence of functional GP in the vector particle was not associated with increased replication in the respiratory tract nor with spread beyond the respiratory tract of HPIV3-naive guinea pigs, indicating that expression and functional incorporation of the attachment/penetration glycoprotein of this systemic virus did not mediate a change in tissue tropism.

  10. Herpes Simplex Vaccines: Prospects of Live-attenuated HSV Vaccines to Combat Genital and Ocular infections

    Science.gov (United States)

    Stanfield, Brent; Kousoulas, Konstantin Gus

    2015-01-01

    Herpes simplex virus type-1 (HSV-1) and its closely related type-2 (HSV-2) viruses cause important clinical manifestations in humans including acute ocular disease and genital infections. These viruses establish latency in the trigeminal ganglionic and dorsal root neurons, respectively. Both viruses are widespread among humans and can frequently reactivate from latency causing disease. Currently, there are no vaccines available against herpes simplex viral infections. However, a number of promising vaccine approaches are being explored in pre-clinical investigations with few progressing to early phase clinical trials. Consensus research findings suggest that robust humoral and cellular immune responses may partially control the frequency of reactivation episodes and reduce clinical symptoms. Live-attenuated viral vaccines have long been considered as a viable option for generating robust and protective immune responses against viral pathogens. Varicella zoster virus (VZV) belongs to the same alphaherpesvirus subfamily with herpes simplex viruses. A live-attenuated VZV vaccine has been extensively used in a prophylactic and therapeutic approach to combat primary and recurrent VZV infection indicating that a similar vaccine approach may be feasible for HSVs. In this review, we summarize pre-clinical approaches to HSV vaccine development and current efforts to test certain vaccine approaches in human clinical trials. Also, we discuss the potential advantages of using a safe, live-attenuated HSV-1 vaccine strain to protect against both HSV-1 and HSV-2 infections. PMID:27114893

  11. Cost Effectiveness of Influenza Vaccine for U.S. Children: Live Attenuated and Inactivated Influenza Vaccine.

    Science.gov (United States)

    Shim, Eunha; Brown, Shawn T; DePasse, Jay; Nowalk, Mary Patricia; Raviotta, Jonathan M; Smith, Kenneth J; Zimmerman, Richard K

    2016-09-01

    Prior studies showed that live attenuated influenza vaccine (LAIV) is more effective than inactivated influenza vaccine (IIV) in children aged 2-8 years, supporting the Centers for Disease Control and Prevention (CDC) recommendations in 2014 for preferential LAIV use in this age group. However, 2014-2015 U.S. effectiveness data indicated relatively poor effectiveness of both vaccines, leading CDC in 2015 to no longer prefer LAIV. An age-structured model of influenza transmission and vaccination was developed, which incorporated both direct and indirect protection induced by vaccination. Based on this model, the cost effectiveness of influenza vaccination strategies in children aged 2-8 years in the U.S. was estimated. The base case assumed a mixed vaccination strategy where 33.3% and 66.7% of vaccinated children aged 2-8 years receive LAIV and IIV, respectively. Analyses were performed in 2014-2015. Using published meta-analysis vaccine effectiveness data (83% LAIV and 64% IIV), exclusive LAIV use would be a cost-effective strategy when vaccinating children aged 2-8 years, whereas IIV would not be preferred. However, when 2014-2015 U.S. effectiveness data (0% LAIV and 15% IIV) were used, IIV was likely to be preferred. The cost effectiveness of influenza vaccination in children aged 2-8 years is highly dependent on vaccine effectiveness; the vaccine type with higher effectiveness is preferred. In general, exclusive IIV use is preferred over LAIV use, as long as vaccine effectiveness is higher for IIV than for LAIV. Copyright © 2016 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  12. A modified live canine parvovirus vaccine. II. Immune response.

    Science.gov (United States)

    Carmichael, L E; Joubert, J C; Pollock, R V

    1983-01-01

    The safety and efficacy of an attenuated canine parvovirus (A-CPV) vaccine was evaluated in both experimental and in field dogs. After parenteral vaccination, seronegative dogs developed hemagglutination-inhibition (HI) antibody titers as early as postvaccination (PV) day 2. Maximal titers occurred within 1 week. Immunity was associated with the persistence of HI antibody titers (titers greater than 80) that endured at least 2 years. Immune dogs challenged with virulent CPV did not shed virus in their feces. The A-CPV vaccine did not cause illness alone or in combination with living canine distemper (CD) and canine adenovirus type-2 (CAV-2) vaccines, nor did it interfere with the immune response to the other viruses. A high rate (greater than 98%) of immunity was engendered in seronegative pups. In contrast, maternal antibody interfered with the active immune response to the A-CPV. More than 95% of the dogs with HI titers less than 10 responded to the vaccine, but only 50% responded when titers were approximately 20. No animal with a titer greater than 80 at the time of vaccination became actively immunized. Susceptibility to virulent CPV during that period when maternal antibody no longer protects against infection, but still prevents active immunization, is the principal cause of vaccinal failure in breeding kennels where CPV is present. Reduction, but not complete elimination, of CPV disease in large breeding kennels occurred within 1-2 months of instituting an A-CPV vaccination program.

  13. Recombinant canine distemper virus serves as bivalent live vaccine against rabies and canine distemper.

    Science.gov (United States)

    Wang, Xijun; Feng, Na; Ge, Jinying; Shuai, Lei; Peng, Liyan; Gao, Yuwei; Yang, Songtao; Xia, Xianzhu; Bu, Zhigao

    2012-07-20

    Effective, safe, and affordable rabies vaccines are still being sought. Attenuated live vaccine has been widely used to protect carnivores from canine distemper. In this study, we generated a recombinant canine distemper virus (CDV) vaccine strain, rCDV-RVG, expressing the rabies virus glycoprotein (RVG) by using reverse genetics. The recombinant virus rCDV-RVG retained growth properties similar to those of vector CDV in Vero cell culture. Animal studies demonstrated that rCDV-RVG was safe in mice and dogs. Mice inoculated intracerebrally or intramuscularly with rCDV-RVG showed no apparent signs of disease and developed a strong rabies virus (RABV) neutralizing antibody response, which completely protected mice from challenge with a lethal dose of street virus. Canine studies showed that vaccination with rCDV-RVG induced strong and long-lasting virus neutralizing antibody responses to RABV and CDV. This is the first study demonstrating that recombinant CDV has the potential to serve as bivalent live vaccine against rabies and canine distemper in animals. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Langerin negative dendritic cells promote potent CD8+ T-cell priming by skin delivery of live adenovirus vaccine microneedle arrays.

    OpenAIRE

    Bachy V; Hervouet C; Becker PD; Chorro L; Carlin LM; Herath S; Papagatsias T; Barbaroux JB; Oh SJ; Benlahrech A; Athanasopoulos T; Dickson G; Patterson S; Kwon SY; Geissmann F

    2013-01-01

    Stabilization of virus protein structure and nucleic acid integrity is challenging yet essential to preserve the transcriptional competence of live recombinant viral vaccine vectors in the absence of a cold chain. When coupled with needle-free skin delivery, such a platform would address an unmet need in global vaccine coverage against HIV and other global pathogens. Herein, we show that a simple dissolvable microneedle array (MA) delivery system preserves the immunogenicity of vaccines encod...

  15. Recombinant vaccines against T. gondii: comparison between homologous and heterologous vaccination protocols using two viral vectors expressing SAG1.

    Science.gov (United States)

    Mendes, Érica Araújo; Fonseca, Flavio G; Casério, Bárbara M; Colina, Janaína P; Gazzinelli, Ricardo Tostes; Caetano, Braulia C

    2013-01-01

    The use of recombinant viral vectors expressing T. gondii antigens is a safe and efficient approach to induce immune response against the parasite and a valuable tool for vaccine development. We have previously protected mice from toxoplasmosis by immunizing the animals with an adenovirus expressing the protein SAG1 (AdSAG1) of T. gondii. We are now looking for ways to improve the vaccination strategy and enhance protection. One limitation of homologous vaccinations (sequential doses of the same vector) is induction of anti-vector immune response that blocks cell transduction, restricts transgene expression and, consequently, compromises the overall outcome of vaccination. One way to avert the effects of anti-vector response is to use different viruses in prime and boost (heterologous vaccination). Bearing this in mind, we generated a modified Vaccinia Virus Ankara encoding SAG1 (MVASAG1), to be tested as boost agent after prime with AdSAG1. Although minor differences were observed in the magnitude of the anti-SAG1 immune response induced by each vaccination protocol, the heterologous immunization with AdSAG1 followed by MVASAG1 resulted in improved capacity to control brain cyst formation in a model of chronic toxoplasmosis in C57BL/6 mice.

  16. Recombinant vaccines against T. gondii: comparison between homologous and heterologous vaccination protocols using two viral vectors expressing SAG1.

    Directory of Open Access Journals (Sweden)

    Érica Araújo Mendes

    Full Text Available The use of recombinant viral vectors expressing T. gondii antigens is a safe and efficient approach to induce immune response against the parasite and a valuable tool for vaccine development. We have previously protected mice from toxoplasmosis by immunizing the animals with an adenovirus expressing the protein SAG1 (AdSAG1 of T. gondii. We are now looking for ways to improve the vaccination strategy and enhance protection. One limitation of homologous vaccinations (sequential doses of the same vector is induction of anti-vector immune response that blocks cell transduction, restricts transgene expression and, consequently, compromises the overall outcome of vaccination. One way to avert the effects of anti-vector response is to use different viruses in prime and boost (heterologous vaccination. Bearing this in mind, we generated a modified Vaccinia Virus Ankara encoding SAG1 (MVASAG1, to be tested as boost agent after prime with AdSAG1. Although minor differences were observed in the magnitude of the anti-SAG1 immune response induced by each vaccination protocol, the heterologous immunization with AdSAG1 followed by MVASAG1 resulted in improved capacity to control brain cyst formation in a model of chronic toxoplasmosis in C57BL/6 mice.

  17. Large-scale adenovirus and poxvirus-vectored vaccine manufacturing to enable clinical trials.

    Science.gov (United States)

    Kallel, Héla; Kamen, Amine A

    2015-05-01

    Efforts to make vaccines against infectious diseases and immunotherapies for cancer have evolved to utilize a variety of heterologous expression systems such as viral vectors. These vectors are often attenuated or engineered to safely deliver genes encoding antigens of different pathogens. Adenovirus and poxvirus vectors are among the viral vectors that are most frequently used to develop prophylactic vaccines against infectious diseases as well as therapeutic cancer vaccines. This mini-review describes the trends and processes in large-scale production of adenovirus and poxvirus vectors to meet the needs of clinical applications. We briefly describe the general principles for the production and purification of adenovirus and poxvirus viral vectors. Currently, adenovirus and poxvirus vector manufacturing methods rely on well-established cell culture technologies. Several improvements have been evaluated to increase the yield and to reduce the overall manufacturing cost, such as cultivation at high cell densities and continuous downstream processing. Additionally, advancements in vector characterization will greatly facilitate the development of novel vectored vaccine candidates. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Recombinant Newcastle disease virus-vectored vaccines against human and animal infectious diseases.

    Science.gov (United States)

    Duan, Zhiqiang; Xu, Houqiang; Ji, Xinqin; Zhao, Jiafu

    2015-01-01

    Recent advances in recombinant genetic engineering techniques have brought forward a leap in designing new vaccines in modern medicine. One attractive strategy is the application of reverse genetics technology to make recombinant Newcastle disease virus (rNDV) deliver protective antigens of pathogens. In recent years, numerous studies have demonstrated that rNDV-vectored vaccines can induce quicker and better humoral and mucosal immune responses than conventional vaccines and are protective against pathogen challenges. With deeper understanding of NDV molecular biology, it is feasible to develop gene-modified rNDV vaccines accompanied by good safety, high efficacy, low toxicity and better immunogenicity. This review summarizes the development of reverse genetics technology in using NDV as a promising vaccine vector to design new vaccines for human and animal use.

  19. Recombinant vesicular stomatitis virus vaccine vectors expressing filovirus glycoproteins lack neurovirulence in nonhuman primates.

    Directory of Open Access Journals (Sweden)

    Chad E Mire

    Full Text Available The filoviruses, Marburg virus and Ebola virus, cause severe hemorrhagic fever with high mortality in humans and nonhuman primates. Among the most promising filovirus vaccines under development is a system based on recombinant vesicular stomatitis virus (rVSV that expresses an individual filovirus glycoprotein (GP in place of the VSV glycoprotein (G. The main concern with all replication-competent vaccines, including the rVSV filovirus GP vectors, is their safety. To address this concern, we performed a neurovirulence study using 21 cynomolgus macaques where the vaccines were administered intrathalamically. Seven animals received a rVSV vector expressing the Zaire ebolavirus (ZEBOV GP; seven animals received a rVSV vector expressing the Lake Victoria marburgvirus (MARV GP; three animals received rVSV-wild type (wt vector, and four animals received vehicle control. Two of three animals given rVSV-wt showed severe neurological symptoms whereas animals receiving vehicle control, rVSV-ZEBOV-GP, or rVSV-MARV-GP did not develop these symptoms. Histological analysis revealed major lesions in neural tissues of all three rVSV-wt animals; however, no significant lesions were observed in any animals from the filovirus vaccine or vehicle control groups. These data strongly suggest that rVSV filovirus GP vaccine vectors lack the neurovirulence properties associated with the rVSV-wt parent vector and support their further development as a vaccine platform for human use.

  20. A simple and rapid approach to develop recombinant avian herpesvirus vectored vaccines using CRISPR/Cas9 system.

    Science.gov (United States)

    Tang, Na; Zhang, Yaoyao; Pedrera, Miriam; Chang, Pengxiang; Baigent, Susan; Moffat, Katy; Shen, Zhiqiang; Nair, Venugopal; Yao, Yongxiu

    2018-01-29

    Herpesvirus of turkeys (HVT) has been successfully used as live vaccine against Marek's disease (MD) worldwide for more than 40 years either alone or in combination with other serotypes. HVT is also widely used as a vector platform for generation of recombinant vaccines against a number of avian diseases such as infectious bursal disease (IBD), Newcastle disease (ND) and avian influenza (AI) using conventional recombination methods or recombineering tools on cloned viral genomes. In the present study, we describe the application of CRISPR/Cas9-based genome editing as a rapid and efficient method of generating HVT recombinants expressing VP2 protein of IBDV. This approach offers an efficient method to introduce other viral antigens into the HVT genome for rapid development of recombinant vaccines. Copyright © 2018 The Pirbright Institute. Published by Elsevier Ltd.. All rights reserved.

  1. Development of Recombinant Vaccine Using Herpesvirus of Turkey (Hvt as Vector for Several Viral Diseases in Poultry Industry

    Directory of Open Access Journals (Sweden)

    Risza Hartawan

    2011-03-01

    Full Text Available Herpesvirus of turkey (HVT has been utilised as live vaccine against Marek’s disease in poultry industry world-wide for many years. However, the potency of HVT is not limited on the Marek’s disease only. Along with rapid development of recombinant technique, the potency of HVT can be broaden for other diseases. As naturally apathogenic virus, HVT is a suitable candidate as vector vaccine to express important antigens of viral pathogens. Several researches have been dedicated to design HVT recombinant vaccine by inserting gene of important virus, such as Marek’s disease virus (MDV, immuno bursal disease virus (IBDV, Newcastle disease virus (NDV and Avian Influenza virus (AIV. Therefore, the future recombinant of HVT has been expected to be better in performance along with the improvement of recombinant technique.

  2. Development of a new live rough vaccine against bovine brucellosis

    International Nuclear Information System (INIS)

    Comerci, D.J.; Ugalde, J.E.; Ugalde, R.A.

    2005-01-01

    Brucella abortus S19 is the most commonly used attenuated live vaccine to prevent bovine brucellosis. In spite of its advantages, S19 has several drawbacks: it is abortive for pregnant cattle, is virulent for humans, and re-vaccination is not advised due to the persistence of anti-lipopolysaccharide (LPS) antibodies that hamper the immunoscreening procedures. For these reasons, there is a continuous search for new bovine vaccine candidates. We have previously characterized the phenotype of the phosphoglucomutase (pgm) gene disruption in Brucella abortus S2308, as well as the possible role for the smooth LPS in virulence and intracellular multiplication. Here we evaluate the vaccine properties of an unmarked deletion mutant of pgm. Western blot analysis of purified lipopolysaccharide and whole-cell extract from Δpgm indicate that it synthesizes O-antigen but is incapable of assembling a complete LPS. In consequence Δpgm has a rough phenotype. Experimental infections of mice indicate that Δpgm is avirulent. Vaccination with Δpgm induces protection levels comparable to those induced by S19, and generates a splenocyte proliferative response and cytokines profile typical of a Th-1 response. The ability of the mutant to generate a strong cellular Th-1 response without eliciting specific O-antigen antibodies highlights the potential use of this mutant as a new live vaccine for cattle. (author)

  3. Monitoring of Antibodies Titre Against Canine Distemper Virus in Ferrets Vaccinated with a Live Modified Vaccine

    Directory of Open Access Journals (Sweden)

    L. Pavlačík

    2007-01-01

    Full Text Available A group of five ferrets vaccinated against the canine distemper virus (CDV was evaluated as to the onset of anti-CDV antibody production and the serum levels of the animals were monitored for one year. The ferrets were immunized with a live attenuated vaccine. The vaccination pattern was as follows: primary vaccination at the age of 6 weeks, fi rst revaccination at 30 days after primary vaccination, and second revaccination after another 30 days. Blood samples were taken prior to primary vaccination and then at 30-day intervals (sampling 1 to 12. The whole experimental cycle covered the period of one year from primary vaccination (till the age of 1 year and 6 weeks. Serum samples were analysed for anti-CDV virus-neutralisation antibodies using a virus-neutralisation test using the Onderstepoort CDV strain. All ferrets had zero virus-neutralisation antibody titres before primary vaccination. Two ferrets produced virus-neutralisation antibodies as a response to first revaccination. A stable antibody level (titre 256 was maintained between months 4 and 11 after primary vaccination and a sudden increase in antibody titre (titres 512 and 1024 - 2048 occurred in both animals in months 11 and 12. The reason for the abrupt rise in antibody titres in the two animals remains unclear. No anti-CDV seroconversion was observed in the three remaining animals. Regarding the results obtained in this study we do not consider commonly recommended vaccination with a live attenuated anti-CDV vaccine as an effective method of antibodies induction against distemper in young ferrets.

  4. Optimal vaccination strategies against vector-borne diseases

    DEFF Research Database (Denmark)

    Græsbøll, Kaare; Enøe, Claes; Bødker, Rene

    2014-01-01

    Using a process oriented semi-agent based model, we simulated the spread of Bluetongue virus by Culicoides, biting midges, between cattle in Denmark. We evaluated the minimum vaccination cover and minimum cost for eight different preventive vaccination strategies in Denmark. The simulation model ...... results when index cases were in the vaccinated areas. However, given that the long-range spread of midge borne disease is still poorly quantified, more robust national vaccination schemes seem preferable....

  5. Vaccines for viral and parasitic diseases produced with baculovirus vectors

    NARCIS (Netherlands)

    Oers, van M.M.

    2006-01-01

    The baculovirus¿insect cell expression system is an approved system for the production of viral antigens with vaccine potential for humans and animals and has been used for production of subunit vaccines against parasitic diseases as well. Many candidate subunit vaccines have been expressed in this

  6. Attenuation of Replication-Competent Adenovirus Serotype 26 Vaccines by Vectorization.

    Science.gov (United States)

    Maxfield, Lori F; Abbink, Peter; Stephenson, Kathryn E; Borducchi, Erica N; Ng'ang'a, David; Kirilova, Marinela M; Paulino, Noelix; Boyd, Michael; Shabram, Paul; Ruan, Qian; Patel, Mayank; Barouch, Dan H

    2015-11-01

    Replication-competent adenovirus (rcAd)-based vaccine vectors may theoretically provide immunological advantages over replication-incompetent Ad vectors, but they also raise additional potential clinical and regulatory issues. We produced replication-competent Ad serotype 26 (rcAd26) vectors by adding the E1 region back into a replication-incompetent Ad26 vector backbone with the E3 or E3/E4 regions deleted. We assessed the effect of vectorization on the replicative capacity of the rcAd26 vaccines. Attenuation occurred in a stepwise fashion, with E3 deletion, E4 deletion, and human immunodeficiency virus type 1 (HIV-1) envelope (Env) gene insertion all contributing to reduced replicative capacity compared to that with the wild-type Ad26 vector. The rcAd26 vector with E3 and E4 deleted and containing the Env transgene exhibited 2.7- to 4.4-log-lower replicative capacity than that of the wild-type Ad26 in vitro. This rcAd26 vector is currently being evaluated in a phase 1 clinical trial. Attenuation as a result of vectorization and transgene insertion has implications for the clinical development of replication-competent vaccine vectors. Copyright © 2015, Maxfield et al.

  7. Protective immunity against tularemia provided by an adenovirus-vectored vaccine expressing Tul4 of Francisella tularensis.

    Science.gov (United States)

    Kaur, Ravinder; Chen, Shan; Arévalo, Maria T; Xu, Qingfu; Chen, Yanping; Zeng, Mingtao

    2012-03-01

    Francisella tularensis, a category A bioterrorism agent, is a highly infectious organism that is passed on via skin contact and inhalation routes. A live attenuated vaccine strain (LVS) has been developed, but it has not been licensed for public use by the FDA due to safety concerns. Thus, there exists a need for a safer and improved vaccine. In this study, we have constructed a replication-incompetent adenovirus, Ad/opt-Tul4, carrying a codon-optimized gene for expression of a membrane protein, Tul4, of F. tularensis LVS. Its ability to protect against lethal challenge and its immunogenicity were evaluated in a murine model. An intramuscular injection of a single dose (1 × 10(7) PFU) of Ad/opt-Tul4 elicited a robust Tul4-specific antibody response. Assays suggest a Th1-driven response. A single dose elicited 20% protection against challenge with 100 × 50% lethal dose (LD(50)) F. tularensis LVS; two additional booster shots resulted in 60% protection. In comparison, three doses of 5 μg recombinant Tul4 protein did not elicit significant protection against challenge. Therefore, the Ad/opt-Tul4 vaccine was more effective than the protein vaccine, and protection was dose dependent. Compared to LVS, the protection rate is lower, but an adenovirus-vectored vaccine may be more attractive due to its enhanced safety profile and mucosal route of delivery. Furthermore, simple genetic modification of the vaccine may potentially produce antibodies protective against a fully virulent strain of F. tularensis. Our data support the development and further research of an adenovirus-vectored vaccine against Tul4 of F. tularensis LVS.

  8. 9 CFR 113.64 - General requirements for live bacterial vaccines.

    Science.gov (United States)

    2010-01-01

    ... bacterial vaccines. 113.64 Section 113.64 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION... STANDARD REQUIREMENTS Live Bacterial Vaccines § 113.64 General requirements for live bacterial vaccines... bacterial vaccine shall meet the requirements in this section. (a) Purity test. Final container samples of...

  9. Driving vaccine innovations to improve lives and livelihoods | CRDI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2 févr. 2018 ... Following the Livestock Vaccine Innovation Fund's first call for proposals, five world-class teams have been funded. Collectively, they represent a cross-section of disciplines, diseases, and regional hot spots, and all present the potential to profoundly transform the lives of smallholder livestock farmers for ...

  10. Live Attenuated Recombinant Vaccine Protects Nonhuman Primates Against Ebola and Marburg Viruses

    National Research Council Canada - National Science Library

    Jones, Steven M; Feldmann, Heinz; Stroher, Ute; Geisbert, Joan B; Fernando, Lisa; Grolla, Allen; Klenk, Hans-Dieter; Sullivan, Nancy J; Volchkov, Viktor E; Fritz, Elizabeth A; Daddario, Kathleen M; Hensley, Lisa E; Jahrling, Peter B; Geisbert, Thomas W

    2005-01-01

    ...). Here, we developed replication-competent vaccines against EBOV and MARV based on attenuated recombinant vesicular stomatitis virus vectors expressing either the EBOV glycoprotein or MARV glycoprotein...

  11. Long-lived tissue resident HIV-1 specific memory CD8+ T cells are generated by skin immunization with live virus vectored microneedle arrays.

    Science.gov (United States)

    Zaric, Marija; Becker, Pablo Daniel; Hervouet, Catherine; Kalcheva, Petya; Ibarzo Yus, Barbara; Cocita, Clement; O'Neill, Lauren Alexandra; Kwon, Sung-Yun; Klavinskis, Linda Sylvia

    2017-12-28

    The generation of tissue resident memory (T RM ) cells at the body surfaces to provide a front line defence against invading pathogens represents an important goal in vaccine development for a wide variety of pathogens. It has been widely assumed that local vaccine delivery to the mucosae is necessary to achieve that aim. Here we characterise a novel micro-needle array (MA) delivery system fabricated to deliver a live recombinant human adenovirus type 5 vaccine vector (AdHu5) encoding HIV-1 gag. We demonstrate rapid dissolution kinetics of the microneedles in skin. Moreover, a consequence of MA vaccine cargo release was the generation of long-lived antigen-specific CD8 + T cells that accumulate in mucosal tissues, including the female genital and respiratory tract. The memory CD8 + T cell population maintained in the peripheral mucosal tissues was attributable to a MA delivered AdHu5 vaccine instructing CD8 + T cell expression of CXCR3 + , CD103 +, CD49a + , CD69 + , CD127 + homing, retention and survival markers. Furthermore, memory CD8 + T cells generated by MA immunization significantly expanded upon locally administered antigenic challenge and showed a predominant poly-functional profile producing high levels of IFNγ and Granzyme B. These data demonstrate that skin vaccine delivery using microneedle technology induces mobilization of long lived, poly-functional CD8 + T cells to peripheral tissues, phenotypically displaying hallmarks of residency and yields new insights into how to design and deliver effective vaccine candidates with properties to exert local immunosurveillance at the mucosal surfaces. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  12. Studies of parvovirus vaccination in the dog: the performance of live attenuated feline parvovirus vaccines.

    Science.gov (United States)

    Thompson, H; McCandlish, I A; Cornwell, H J; Macartney, L; Maxwell, N S; Weipers, A F; Wills, I R; Black, J A; Mackenzie, A C

    1988-04-16

    The performance of three live attenuated feline parvovirus vaccines licensed for use in the dog was studied. At the end of the primary vaccination course 67 per cent of dogs had inadequate antibody levels (less than or equal to 32) as measured by a haemagglutination inhibition test. Interference by maternal antibody accounted for some of the failures but the fact that there was no significant difference in performance between dogs vaccinated at 12 weeks or 16 weeks of age indicated that maternal antibody was not the only factor.

  13. In-Depth Characterization of Live Vaccines Used in Europe for Oral Rabies Vaccination of Wildlife.

    Directory of Open Access Journals (Sweden)

    Florence Cliquet

    Full Text Available Although rabies incidence has fallen sharply over the past decades in Europe, the disease is still present in Eastern Europe. Oral rabies immunization of wild animal rabies has been shown to be the most effective method for the control and elimination of rabies. All rabies vaccines used in Europe are modified live virus vaccines based on the Street Alabama Dufferin (SAD strain isolated from a naturally-infected dog in 1935. Because of the potential safety risk of a live virus which could revert to virulence, the genetic composition of three commercial attenuated live rabies vaccines was investigated in two independent laboratories using next genome sequencing. This study is the first one reporting on the diversity of variants in oral rabies vaccines as well as the presence of a mix of at least two different variants in all tested batches. The results demonstrate the need for vaccine producers to use new robust methodologies in the context of their routine vaccine quality controls prior to market release.

  14. A nonproliferating parvovirus vaccine vector elicits sustained, protective humoral immunity following a single intravenous or intranasal inoculation.

    Science.gov (United States)

    Palmer, Gene A; Brogdon, Jennifer L; Constant, Stephanie L; Tattersall, Peter

    2004-02-01

    An ideal vaccine delivery system would elicit persistent protection following a single administration, preferably by a noninvasive route, and be safe even in the face of immunosuppression, either inherited or acquired, of the recipient. We have exploited the unique life cycle of the autonomous parvoviruses to develop a nonproliferating vaccine platform that appears to both induce priming and continually boost a protective immune response following a single inoculation. A crippled parvovirus vector was constructed, based on a chimera between minute virus of mice (MVM) and LuIII, which expresses Borrelia burgdorferi outer surface protein A (OspA) instead of its coat protein. The vector was packaged into an MVM lymphotropic capsid and inoculated into naive C3H/HeNcr mice. Vaccination with a single vector dose, either intravenously or intranasally, elicited high-titer anti-OspA-specific antibody that provided protection from live spirochete challenge and was sustained over the lifetime of the animal. Both humoral and cell-mediated Th(1) immunity was induced, as shown by anti-OspA immunoglobulin G2a antibody and preferential gamma interferon production by OspA-specific CD4(+) T cells.

  15. Distinct susceptibility of HIV vaccine vector-induced CD4 T cells to HIV infection

    Science.gov (United States)

    Niu, Qingli; Hou, Wei; Churchyard, Gavin; Nitayaphan, Sorachai; Pitisuthithum, Punnee; Rerks-Ngarm, Supachai; Franchini, Genoveffa

    2018-01-01

    The concerns raised from adenovirus 5 (Ad5)-based HIV vaccine clinical trials, where excess HIV infections were observed in some vaccine recipients, have highlighted the importance of understanding host responses to vaccine vectors and the HIV susceptibility of vector-specific CD4 T cells in HIV vaccination. Our recent study reported that human Ad5-specific CD4 T cells induced by Ad5 vaccination (RV156A trial) are susceptible to HIV. Here we further investigated the HIV susceptibility of vector-specific CD4 T cells induced by ALVAC, a canarypox viral vector tested in the Thai trial RV144, as compared to Ad5 vector-specific CD4 T cells in the HVTN204 trial. We showed that while Ad5 vector-specific CD4 T cells were readily susceptible to HIV, ALVAC-specific CD4 T cells in RV144 PBMC were substantially less susceptible to both R5 and X4 HIV in vitro. The lower HIV susceptibility of ALVAC-specific CD4 T cells was associated with the reduced surface expression of HIV entry co-receptors CCR5 and CXCR4 on these cells. Phenotypic analyses identified that ALVAC-specific CD4 T cells displayed a strong Th1 phenotype, producing higher levels of IFN-γ and CCL4 (MIP-1β) but little IL-17. Of interest, ALVAC and Ad5 vectors induced distinct profiles of vector-specific CD8 vs. CD4 T-cell proliferative responses in PBMC, with ALVAC preferentially inducing CD8 T-cell proliferation, while Ad5 vector induced CD4 T-cell proliferation. Depletion of ALVAC-, but not Ad5-, induced CD8 T cells in PBMC led to a modest increase in HIV infection of vector-specific CD4 T cells, suggesting a role of ALVAC-specific CD8 T cells in protecting ALVAC-specific CD4 T cells from HIV. Taken together, our data provide strong evidence for distinct HIV susceptibility of CD4 T cells induced by different vaccine vectors and highlight the importance of better evaluating anti-vector responses in HIV vaccination. PMID:29474461

  16. Live attenuated vaccines: Historical successes and current challenges.

    Science.gov (United States)

    Minor, Philip D

    2015-05-01

    Live attenuated vaccines against human viral diseases have been amongst the most successful cost effective interventions in medical history. Smallpox was declared eradicated in 1980; poliomyelitis is nearing global eradication and measles has been controlled in most parts of the world. Vaccines function well for acute diseases such as these but chronic infections such as HIV are more challenging for reasons of both likely safety and probable efficacy. The derivation of the vaccines used has in general not been purely rational except in the sense that it has involved careful clinical trials of candidates and subsequent careful follow up in clinical use; the identification of the candidates is reviewed. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

  17. Adenovirus-Vectored Vaccine as a Rapid-Response Tool Against Avian Influenza Pandemic

    International Nuclear Information System (INIS)

    Van Kampen, K. R.; Tang, D. C.

    2007-01-01

    Influenza viruses in nature undergo genetic mutation and reassortment. Three pandemics of avian influenza in man were recorded in the twentieth century. Highly pathogenic avian influenza (HPAI) viruses currently in circulation pose a threat for another world-wide pandemic, if they become transmissible from man to man. Manufacturing protective vaccines using current egg-based technology is often difficult due to the virulence of the virus and its adverse effects on the embryonating egg substrate. New technologies allow the creation of safe and protective pandemic influenza vaccines without the need for egg based substrates. These technologies allow new vaccines to be created in less than one month. Manufacturing is in tissue culture, not eggs. Vaccine can be administered to man non-invasively, without adjuvants, eliciting a rapid and protective immune response. Protective immunity against avian influenza (AI) virus was elicited in chickens by single-dose in ovo vaccination with a replication-competent adenovirus (RCA)-free human adenovirus serotype 5 (Ad5)-derived vector encoding an H5N9 avian influenza virus hemagglutinin. Vaccinated chickens were protected against both H5N1 and H5N2 HPAI virus challenges. Mass-administration of this bird flu vaccine can be streamlined with available robotic in ovo injectors. Vaccination using this vaccine could protect the the largest host reservoir (chickens) and greatly reduce the exposure of man to avian influenza. In addition, Ad5-vectored vaccines can be produced rapidly and the safety margin of a non-replicating vector is superior to that of a replicating counterpart. Furthermore, this mode of vaccination is compatible with epidemiological surveys of natural AI virus infections. In addition to mass immunization of poultry, both animals and humans have been effectively immunized by intranasal administration of Ad5-vectored influenza vaccines without any appreciable side effects, even in mice and human volunteers with

  18. New gorilla adenovirus vaccine vectors induce potent immune responses and protection in a mouse malaria model.

    Science.gov (United States)

    Limbach, Keith; Stefaniak, Maureen; Chen, Ping; Patterson, Noelle B; Liao, Grant; Weng, Shaojie; Krepkiy, Svetlana; Ekberg, Greg; Torano, Holly; Ettyreddy, Damodar; Gowda, Kalpana; Sonawane, Sharvari; Belmonte, Arnel; Abot, Esteban; Sedegah, Martha; Hollingdale, Michael R; Moormann, Ann; Vulule, John; Villasante, Eileen; Richie, Thomas L; Brough, Douglas E; Bruder, Joseph T

    2017-07-03

    A DNA-human Ad5 (HuAd5) prime-boost malaria vaccine has been shown to protect volunteers against a controlled human malaria infection. The potency of this vaccine, however, appeared to be affected by the presence of pre-existing immunity against the HuAd5 vector. Since HuAd5 seroprevalence is very high in malaria-endemic areas of the world, HuAd5 may not be the most appropriate malaria vaccine vector. This report describes the evaluation of the seroprevalence, immunogenicity and efficacy of three newly identified gorilla adenoviruses, GC44, GC45 and GC46, as potential malaria vaccine vectors. The seroprevalence of GC44, GC45 and GC46 is very low, and the three vectors are not efficiently neutralized by human sera from Kenya and Ghana, two countries where malaria is endemic. In mice, a single administration of GC44, GC45 and GC46 vectors expressing a murine malaria gene, Plasmodium yoelii circumsporozoite protein (PyCSP), induced robust PyCSP-specific T cell and antibody responses that were at least as high as a comparable HuAd5-PyCSP vector. Efficacy studies in a murine malaria model indicated that a prime-boost regimen with DNA-PyCSP and GC-PyCSP vectors can protect mice against a malaria challenge. Moreover, these studies indicated that a DNA-GC46-PyCSP vaccine regimen was significantly more efficacious than a DNA-HuAd5-PyCSP regimen. These data suggest that these gorilla-based adenovectors have key performance characteristics for an effective malaria vaccine. The superior performance of GC46 over HuAd5 highlights its potential for clinical development.

  19. Further development of raccoon poxvirus-vectored vaccines against plague (Yersinia pestis)

    Science.gov (United States)

    Rocke, Tonie E.; Iams, Keith P.; Dawe, S.; Smith, Susan; Williamson, Judy L.; Heisey, Dennis M.; Osorio, Jorge E.

    2009-01-01

    In previous studies, we demonstrated protection against plague in mice and prairie dogs using a raccoon pox (RCN) virus-vectored vaccine that expressed the F1 capsular antigen of Yersinia pestis. In order to improve vaccine efficacy, we have now constructed additional RCN-plague vaccines containing two different forms of the lcrV (V) gene, including full-length (Vfull) and a truncated form (V307). Mouse challenge studies with Y. pestis strain CO92 showed that vaccination with a combination of RCN-F1 and the truncated V construct (RCN-V307) provided the greatest improvement (P = 0.01) in protection against plague over vaccination with RCN-F1 alone. This effect was mediated primarily by anti-F1 and anti-V antibodies and both contributed independently to increased survival of vaccinated mice.

  20. Comparative evaluation of three capripoxvirus-vectored peste des petits ruminants vaccines.

    Science.gov (United States)

    Fakri, F; Bamouh, Z; Ghzal, F; Baha, W; Tadlaoui, K; Fihri, O Fassi; Chen, W; Bu, Z; Elharrak, M

    2018-01-15

    Sheep and goat pox (SGP) with peste des petits ruminants (PPR) are transboundary viral diseases of small ruminants that cause huge economic losses. Recombinant vaccines that can protect from both infections have been reported as a promising solution for the future. SGP was used as a vector to express two structural proteins hemagglutinin or the fusion protein of PPRV. We compared immunity conferred by recombinant capripoxvirus vaccines expressing H or F or both HF. Safety and efficacy were evaluated in goats and sheep. Two vaccine doses were tested in sheep, 10 4.5 TCDI50 in 1ml dose was retained for the further experiment. Results showed that the recombinant HF confers an earlier and stronger immunity against both SGP and PPR. This recombinant vaccine protect also against the disease in exposed and unexposed sheep. The potential Differentiating Infected from Vaccinated Animals of recombinant vaccines is of great advantage in any eradication program. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Evaluation of yellow fever virus 17D strain as a new vector for HIV-1 vaccine development.

    Science.gov (United States)

    Franco, David; Li, Wenjing; Qing, Fang; Stoyanov, Cristina T; Moran, Thomas; Rice, Charles M; Ho, David D

    2010-08-09

    The failure to develop an effective vaccine against HIV-1 infection has led the research community to seek new ways of raising qualitatively different antibody and cellular immune responses. Towards this goal, we investigated the yellow fever 17D vaccine strain (YF17D), one of the most effective vaccines ever made, as a platform for HIV-1 vaccine development. A test antigen, HIV-1 p24 (clade B consensus), was inserted near the 5' end of YF17D, in frame and upstream of the polyprotein (YF-5'/p24), or between the envelope and the first non-structural protein (YF-E/p24/NS1). In vitro characterization of these recombinants indicated that the gene insert was more stable in the context of YF-E/p24/NS1. This was confirmed in immunogenicity studies in mice. CD8(+) IFN-gamma T-cell responses against p24 were elicited by the YF17D recombinants, as were specific CD4(+) T cells expressing IFN-gamma and IL-2. A balanced CD4(+) and CD8(+) T-cell response was notable, as was the polyfunctionality of the responding cells. Finally, the protective efficacy of the YF17D recombinants, particularly YF-E/p24/NS1, in mice challenged with a vaccinia expressing HIV-1 Gag was demonstrated. These results suggest that YF17D warrants serious consideration as a live-attenuated vector for HIV-1 vaccine development. Copyright 2010 Elsevier Ltd. All rights reserved.

  2. Live attenuated vaccines: Historical successes and current challenges

    Energy Technology Data Exchange (ETDEWEB)

    Minor, Philip D., E-mail: Philip.Minor@nibsc.org

    2015-05-15

    Live attenuated vaccines against human viral diseases have been amongst the most successful cost effective interventions in medical history. Smallpox was declared eradicated in 1980; poliomyelitis is nearing global eradication and measles has been controlled in most parts of the world. Vaccines function well for acute diseases such as these but chronic infections such as HIV are more challenging for reasons of both likely safety and probable efficacy. The derivation of the vaccines used has in general not been purely rational except in the sense that it has involved careful clinical trials of candidates and subsequent careful follow up in clinical use; the identification of the candidates is reviewed. - Highlights: • Live vaccines against human diseases caused by viruses have been very successful. • They have been developed by empirical clinical studies and problems identified in later use. • It can be difficult to balance ability to cause disease and ability to immunise for a strain. • There is currently no reliable basis for predicting success from pure virological studies. • Vaccinia, which eradicated smallpox, is the paradigm for all successes and issues.

  3. Live attenuated vaccines: Historical successes and current challenges

    International Nuclear Information System (INIS)

    Minor, Philip D.

    2015-01-01

    Live attenuated vaccines against human viral diseases have been amongst the most successful cost effective interventions in medical history. Smallpox was declared eradicated in 1980; poliomyelitis is nearing global eradication and measles has been controlled in most parts of the world. Vaccines function well for acute diseases such as these but chronic infections such as HIV are more challenging for reasons of both likely safety and probable efficacy. The derivation of the vaccines used has in general not been purely rational except in the sense that it has involved careful clinical trials of candidates and subsequent careful follow up in clinical use; the identification of the candidates is reviewed. - Highlights: • Live vaccines against human diseases caused by viruses have been very successful. • They have been developed by empirical clinical studies and problems identified in later use. • It can be difficult to balance ability to cause disease and ability to immunise for a strain. • There is currently no reliable basis for predicting success from pure virological studies. • Vaccinia, which eradicated smallpox, is the paradigm for all successes and issues

  4. Principles underlying rational design of live attenuated influenza vaccines

    Science.gov (United States)

    Jang, Yo Han

    2012-01-01

    Despite recent innovative advances in molecular virology and the developments of vaccines, influenza virus remains a serious burden for human health. Vaccination has been considered a primary countermeasure for prevention of influenza infection. Live attenuated influenza vaccines (LAIVs) are particularly attracting attention as an effective strategy due to several advantages over inactivated vaccines. Cold-adaptation, as a classical means for attenuating viral virulence, has been successfully used for generating safe and effective donor strains of LAIVs against seasonal epidemics and occasional pandemics. Recently, the advent of reverse genetics technique expedited a variety of rational strategies to broaden the pool of LAIVs. Considering the breadth of antigenic diversity of influenza virus, the pool of LAIVs is likely to equip us with better options for controlling influenza pandemics. With a brief reflection on classical attenuating strategies used at the initial stage of development of LAIVs, especially on the principles underlying the development of cold-adapted LAIVs, we further discuss and outline other attenuation strategies especially with respect to the rationales for attenuation, and their practicality for mass production. Finally, we propose important considerations for a rational vaccine design, which will provide us with practical guidelines for improving the safety and effectiveness of LAIVs. PMID:23596576

  5. The recombinant EHV-1 vector producing CDV hemagglutinin as potential vaccine against canine distemper.

    Science.gov (United States)

    Pan, Zihao; Liu, Jin; Ma, Jiale; Jin, Qiuli; Yao, Huochun; Osterrieder, Nikolaus

    2017-10-01

    Canine distemper virus (CDV), is a pantropic agent of morbillivirus that causes fetal disease in dogs. Base on a broad host rang of CDV, the continued vaccines inoculation is unavoidable to pose gene recombination risk in vaccine virus and wild virus. The current study presents the construction of novel vectors, using equine herpesvirus type 1 (EHV-1) expressing the canine distemper virus (CDV). The recent field strain hemagglutinin protein and nucleoprotein were used for the construction of the viral vector vaccines. Based on the Bacterial artificial chromosome (BAC) genomes of EHV-1 RacH strain, the recombinant EHV-1 vaccine virus encoding CDV hemagglutinin protein (EHV-H) or CDV nucleoprotein (EHV-N) was constructed separately. The constructed BACs were rescued after 72 h post infection, and the expression of H or N in the recombinant viruses was confirmed by western-blotting. Furthermore, high levels of neutralizing antibodies were induced persistently following vaccination in the groups EHV-H&EHV-N and EHV-H, but the EHV-N group. The groups of vaccinated EHV-H and EHV-H&EHV-N pups were monitored for clinical signs, whereas the vaccinated EHV-N group developed moderate symptoms. The present study demonstrated that EHV-1 based recombinant virus carrying CDV H could be a promising vaccine candidate against canine distemper. Copyright © 2017. Published by Elsevier Ltd.

  6. Complex adenovirus-vectored vaccine protects guinea pigs from three strains of Marburg virus challenges

    International Nuclear Information System (INIS)

    Wang Danher; Hevey, Michael; Juompan, Laure Y.; Trubey, Charles M.; Raja, Nicholas U.; Deitz, Stephen B.; Woraratanadharm, Jan; Luo Min; Yu Hong; Swain, Benjamin M.; Moore, Kevin M.; Dong, John Y.

    2006-01-01

    The Marburg virus (MARV), an African filovirus closely related to the Ebola virus, causes a deadly hemorrhagic fever in humans, with up to 90% mortality. Currently, treatment of disease is only supportive, and no vaccines are available to prevent spread of MARV infections. In order to address this need, we have developed and characterized a novel recombinant vaccine that utilizes a single complex adenovirus-vectored vaccine (cAdVax) to overexpress a MARV glycoprotein (GP) fusion protein derived from the Musoke and Ci67 strains of MARV. Vaccination with the cAdVaxM(fus) vaccine led to efficient production of MARV-specific antibodies in both mice and guinea pigs. Significantly, guinea pigs vaccinated with at least 5 x 10 7 pfu of cAdVaxM(fus) vaccine were 100% protected against lethal challenges by the Musoke, Ci67 and Ravn strains of MARV, making it a vaccine with trivalent protective efficacy. Therefore, the cAdVaxM(fus) vaccine serves as a promising vaccine candidate to prevent and contain multi-strain infections by MARV

  7. Applications of pox virus vectors to vaccination: an update.

    OpenAIRE

    Paoletti, E

    1996-01-01

    Recombinant pox viruses have been generated for vaccination against heterologous pathogens. Amongst these, the following are notable examples. (i) The engineering of the Copenhagen strain of vaccinia virus to express the rabies virus glycoprotein. When applied in baits, this recombinant has been shown to vaccinate the red fox in Europe and raccoons in the United States, stemming the spread of rabies virus infection in the wild. (ii) A fowlpox-based recombinant expressing the Newcastle disease...

  8. Membrane-bound SIV envelope trimers are immunogenic in ferrets after intranasal vaccination with a replication-competent canine distemper virus vector.

    Science.gov (United States)

    Zhang, Xinsheng; Wallace, Olivia; Wright, Kevin J; Backer, Martin; Coleman, John W; Koehnke, Rebecca; Frenk, Esther; Domi, Arban; Chiuchiolo, Maria J; DeStefano, Joanne; Narpala, Sandeep; Powell, Rebecca; Morrow, Gavin; Boggiano, Cesar; Zamb, Timothy J; Richter King, C; Parks, Christopher L

    2013-11-01

    We are investigating canine distemper virus (CDV) as a vaccine vector for the delivery of HIV envelope (Env) that closely resembles the native trimeric spike. We selected CDV because it will promote vaccine delivery to lymphoid tissues, and because human exposure is infrequent, reducing potential effects of pre-existing immunity. Using SIV Env as a model, we tested a number of vector and gene insert designs. Vectors containing a gene inserted between the CDV H and L genes, which encoded Env lacking most of its cytoplasmic tail, propagated efficiently in Vero cells, expressed the immunogen on the cell surface, and incorporated the SIV glycoprotein into progeny virus particles. When ferrets were vaccinated intranasally, there were no signs of distress, vector replication was observed in the gut-associated lymphoid tissues, and the animals produced anti-SIV Env antibodies. These data show that live CDV-SIV Env vectors can safely induce anti-Env immune responses following intranasal vaccination. © 2013 Elsevier Inc. All rights reserved.

  9. Chimeric avian paramyxovirus-based vector immunization against highly pathogenic avian influenza followed by conventional Newcastle disease vaccination eliminates lack of protection from virulent ND virus

    Directory of Open Access Journals (Sweden)

    C. Steglich

    2014-01-01

    Full Text Available Recently, we described a chimeric, hemagglutinin of highly pathogenic avian influenza virus (HPAIV H5 expressing Newcastle disease virus (NDV-based vector vaccine (chNDVFHNPMV8H5 in which NDV envelope glycoproteins were replaced by those of avian paramyxovirus-8 (APMV-8. This chimeric vaccine induced solid protection against lethal HPAIV H5N1 even in chickens with maternal antibodies against NDV (MDA+. However, due to the absence of the major NDV immunogens it failed to induce protection against Newcastle disease (ND. Here, we report on protection of MDA+ chickens against HPAI H5N1 and ND, by vaccination with chNDVFHNPMV8H5 either on day 1 or day seven after hatch, and subsequent immunization with live attenuated NDV seven days later. Vaccination was well tolerated and three weeks after immunization, challenge infections with highly pathogenic NDV as well as HPAIV H5N1 were carried out. All animals remained healthy without exhibiting any clinical signs, whereas non-vaccinated animals showed morbidity and mortality. Therefore, vaccination with chNDVFHNPMV8H5 can be followed by NDV vaccination to protect chickens from HPAIV as well as NDV, indicating that the antibody response against chNDVFHNPMV8H5 does not interfere with live ND vaccination.

  10. Safety of the novel influenza viral vector Brucella abortus vaccine in pregnant heifers

    Directory of Open Access Journals (Sweden)

    Kaissar Tabynov

    2016-01-01

    Full Text Available ABSTRACT: The present study provides the first information about the safety of a new influenza viral vector vaccine expressing the Brucella ribosomal protein L7/L12 or Omp16 containing the adjuvant Montanide Gel01 in pregnant heifers. Immunization of pregnant heifers was conducted via the conjunctival (n=10 or subcutaneous (n=10 route using cross prime and booster vaccination schedules at an interval of 28 days. The vector vaccine was evaluated in comparison with positive control groups vaccinated with B. abortus S19 (n=10 or B. abortus RB51 (n=10 and a negative (PBS+Montanide Gel01; n=10 control group. Clinical studies, thermometry, assessment of local reactogenicity and observation of abortion showed that the vector vaccine via the conjunctival or subcutaneous route was completely safe for pregnant heifers compared to the commercial vaccines B. abortus S19 or B. abortus RB51. The only single adverse event was the formation of infiltration at the site of subcutaneous injection; this reaction was not observed for the conjunctival route.

  11. Advances and Future Challenges in Recombinant Adenoviral Vectored H5N1 Influenza Vaccines

    Directory of Open Access Journals (Sweden)

    Jianfeng Zhang

    2012-11-01

    Full Text Available The emergence of a highly pathogenic avian influenza virus H5N1 has increased the potential for a new pandemic to occur. This event highlights the necessity for developing a new generation of influenza vaccines to counteract influenza disease. These vaccines must be manufactured for mass immunization of humans in a timely manner. Poultry should be included in this policy, since persistent infected flocks are the major source of avian influenza for human infections. Recombinant adenoviral vectored H5N1 vaccines are an attractive alternative to the currently licensed influenza vaccines. This class of vaccines induces a broadly protective immunity against antigenically distinct H5N1, can be manufactured rapidly, and may allow mass immunization of human and poultry. Recombinant adenoviral vectors derived from both human and non-human adenoviruses are currently being investigated and appear promising both in nonclinical and clinical studies. This review will highlight the current status of various adenoviral vectored H5N1 vaccines and will outline novel approaches for the future.

  12. Vaccinating high-risk children with the intranasal live-attenuated influenza vaccine: the Quebec experience.

    Science.gov (United States)

    Quach, Caroline

    2014-12-01

    Given the burden of illness associated with influenza, vaccination is recommended for individuals at high risk of complications. The live-attenuated influenza vaccine (LAIV) is administered by intranasal spray, thus directly stimulating mucosal immunity. In this review, we aimed to provide evidence for its efficacy and safety in different paediatric populations. We also share the Quebec experience of LAIV use through a publicly funded vaccination program for children with chronic, high-risk conditions. from randomized controlled trials in healthy children and in asthmatics have demonstrated superior efficacy of LAIV over the injectable vaccine (IIV). LAIV is well tolerated: its administration is associated with runny nose and nasal congestion, but not with asthma exacerbations and is well tolerated in children with cystic fibrosis, when compared to IIV. The vaccine is well accepted by children and parents and can easily be part of vaccination clinics in paediatric tertiary care centres targeting children with chronic, high-risk conditions, not leading to immunosuppression. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. An antivector vaccine protects against a lethal vector-borne pathogen.

    Directory of Open Access Journals (Sweden)

    Milan Labuda

    2006-04-01

    Full Text Available Vaccines that target blood-feeding disease vectors, such as mosquitoes and ticks, have the potential to protect against the many diseases caused by vector-borne pathogens. We tested the ability of an anti-tick vaccine derived from a tick cement protein (64TRP of Rhipicephalus appendiculatus to protect mice against tick-borne encephalitis virus (TBEV transmitted by infected Ixodes ricinus ticks. The vaccine has a "dual action" in immunized animals: when infested with ticks, the inflammatory and immune responses first disrupt the skin feeding site, resulting in impaired blood feeding, and then specific anti-64TRP antibodies cross-react with midgut antigenic epitopes, causing rupture of the tick midgut and death of engorged ticks. Three parameters were measured: "transmission," number of uninfected nymphal ticks that became infected when cofeeding with an infected adult female tick; "support," number of mice supporting virus transmission from the infected tick to cofeeding uninfected nymphs; and "survival," number of mice that survived infection by tick bite and subsequent challenge by intraperitoneal inoculation of a lethal dose of TBEV. We show that one dose of the 64TRP vaccine protects mice against lethal challenge by infected ticks; control animals developed a fatal viral encephalitis. The protective effect of the 64TRP vaccine was comparable to that of a single dose of a commercial TBEV vaccine, while the transmission-blocking effect of 64TRP was better than that of the antiviral vaccine in reducing the number of animals supporting virus transmission. By contrast, the commercial antitick vaccine (TickGARD that targets only the tick's midgut showed transmission-blocking activity but was not protective. The 64TRP vaccine demonstrates the potential to control vector-borne disease by interfering with pathogen transmission, apparently by mediating a local cutaneous inflammatory immune response at the tick-feeding site.

  14. Comparative Efficacy of Feline Leukemia Virus (FeLV) Inactivated Whole-Virus Vaccine and Canarypox Virus-Vectored Vaccine during Virulent FeLV Challenge and Immunosuppression.

    Science.gov (United States)

    Patel, M; Carritt, K; Lane, J; Jayappa, H; Stahl, M; Bourgeois, M

    2015-07-01

    Four vaccines for feline leukemia virus (FeLV) are available in the United States. This study's purpose was to compare the efficacy of Nobivac feline 2-FeLV (an inactivated, adjuvanted whole-virus vaccine) and PureVax recombinant FeLV (a live, canarypox virus-vectored vaccine) following FeLV challenge. Cats were vaccinated at 9 and 12 weeks with Nobivac feline 2-FeLV (group A, n = 11) or PureVax recombinant FeLV (group B, n = 10). Group C (n = 11) comprised unvaccinated controls. At 3 months postvaccination, cats were immunosuppressed and challenged with FeLV-A/61E. The outcomes measured were persistent antigenemia at 12 weeks postchallenge (PC) and proviral DNA and viral RNA at 3 to 9 weeks PC. Persistent antigenemia was observed in 0 of 11 cats in group A, 5 of 10 cats in group B, and 10 of 11 cats in group C. Group A was significantly protected compared to those in groups B (P 0.063). The preventable fraction was 100% for group A and 45% for group B. At 9 weeks PC, proviral DNA and viral RNA were detected 1 of 11 cats in group A, 6 of 10 cats in group B, and 9 of 11 cats in group C. Nucleic acid loads were significantly lower in group A than in group C (P feline 2-FeLV-vaccinated cats were fully protected against persistent antigenemia and had significantly smaller amounts of proviral DNA and plasma viral RNA loads than PureVax recombinant FeLV-vaccinated cats and unvaccinated controls. Copyright © 2015, Patel et al.

  15. Immunogenicity of heterologous recombinant adenovirus prime-boost vaccine regimens is enhanced by circumventing vector cross-reactivity

    NARCIS (Netherlands)

    Thorner, Anna R.; Lemckert, Angelique A. C.; Goudsmit, Jaap; Lynch, Diana M.; Ewald, Bonnie A.; Denholtz, Matthew; Havenga, Menzo J. E.; Barouch, Dan H.

    2006-01-01

    The high prevalence of preexisting immunity to adenovirus serotype 5 (Ad5) in human populations has led to the development of recombinant adenovirus (rAd) vectors derived from rare Ad serotypes as vaccine candidates for human immunodeficiency virus type 1 and other pathogens. Vaccine vectors have

  16. Role of complement and antibodies in controlling infection with pathogenic simian immunodeficiency virus (SIV in macaques vaccinated with replication-deficient viral vectors

    Directory of Open Access Journals (Sweden)

    Strasak Alexander

    2009-06-01

    Full Text Available Abstract Background We investigated the interplay between complement and antibodies upon priming with single-cycle replicating viral vectors (SCIV encoding SIV antigens combined with Adeno5-SIV or SCIV pseudotyped with murine leukemia virus envelope boosting strategies. The vaccine was applied via spray-immunization to the tonsils of rhesus macaques and compared with systemic regimens. Results Independent of the application regimen or route, viral loads were significantly reduced after challenge with SIVmac239 (p Conclusion The heterologous prime-boost strategy with replication-deficient viral vectors administered exclusively via the tonsils did not induce any neutralizing antibodies before challenge. However, after challenge, comparable SIV-specific humoral immune responses were observed in all vaccinated animals. Immunization with single cycle immunodeficiency viruses mounts humoral immune responses comparable to live-attenuated immunodeficiency virus vaccines.

  17. A novel multi-antigen virally vectored vaccine against Mycobacterium avium subspecies paratuberculosis.

    Science.gov (United States)

    Bull, Tim J; Gilbert, Sarah C; Sridhar, Saranya; Linedale, Richard; Dierkes, Nicola; Sidi-Boumedine, Karim; Hermon-Taylor, John

    2007-11-28

    Mycobacterium avium subspecies paratuberculosis causes systemic infection and chronic intestinal inflammation in many species including primates. Humans are exposed through milk and from sources of environmental contamination. Hitherto, the only vaccines available against Mycobacterium avium subspecies paratuberculosis have been limited to veterinary use and comprised attenuated or killed organisms. We developed a vaccine comprising a fusion construct designated HAV, containing components of two secreted and two cell surface Mycobacterium avium subspecies paratuberculosis proteins. HAV was transformed into DNA, human Adenovirus 5 (Ad5) and Modified Vaccinia Ankara (MVA) delivery vectors. Full length expression of the predicted 95 kDa fusion protein was confirmed. Vaccination of naïve and Mycobacterium avium subspecies paratuberculosis infected C57BL/6 mice using DNA-prime/MVA-boost or Ad5-prime/MVA-boost protocols was highly immunogenic resulting in significant IFN-gamma ELISPOT responses by splenocytes against recombinant vaccine antigens and a range of HAV specific peptides. This included strong recognition of a T-cell epitope GFAEINPIA located near the C-terminus of the fusion protein. Antibody responses to recombinant vaccine antigens and HAV specific peptides but not GFAEINPIA, also occurred. No immune recognition of vaccine antigens occurred in any sham vaccinated Mycobacterium avium subspecies paratuberculosis infected mice. Vaccination using either protocol significantly attenuated pre-existing Mycobacterium avium subspecies paratuberculosis infection measured by qPCR in spleen and liver and the Ad5-prime/MVA-boost protocol also conferred some protection against subsequent challenge. No adverse effects of vaccination occurred in any of the mice. A range of modern veterinary and clinical vaccines for the treatment and prevention of disease caused by Mycobacterium avium subspecies paratuberculosis are needed. The present vaccine proved to be highly

  18. pLIVE-EGFP: A liver specific vector carrying the EGFP reporter for ...

    African Journals Online (AJOL)

    -EGFP gene at the Xho I site of the pLIVE vector. The pLIVE-EGFP vector permits simultaneous expression of a gene of interest in addition to the EGFP reporter, specifically within liver cells, both in vivo and in vitro. When expressed in liver cells ...

  19. Protection conferred by a live avian metapneumovirus vaccine when co-administered with live La Sota Newcastle disease vaccine in chicks

    Directory of Open Access Journals (Sweden)

    Kannan Ganapathy

    2014-06-01

    Full Text Available This paper examines the effects on specific pathogen-free (SPF chicks when avian metapneumovirus (aMPV and Newcastle disease virus (NDV La Sota strain vaccines are co-administered. Day-old SPF chicks were divided into five groups. The first group was inoculated with sterile water (SW and the rest of the groups were inoculated with live NDV vaccine VG/GA by the oculo-oral route. At 21 days-old, the unvaccinated chicks were again inoculated with SW. The four VG/GA-vaccinated groups were further inoculated with (i SW, (ii live aMPV vaccine, (iii live NDV La Sota, or (iv combined live NDV La Sota and live aMPV, respectively. Chicks were monitored for post-vaccination reactions and oropharyngeal swabs were collected for vaccines detection. Blood samples were collected to detect aMPV ELISA and NDV haemagglutination-inhibition antibodies. Twenty-one days following the second vaccination, six chicks from each group were challenged with virulent NDV or aMPV respectively. Chicks were monitored for clinical signs and mortality and oropharyngeal swabs collected for aMPV detection. Results showed that, when challenged with a virulent aMPV, both chicks previously vaccinated with VG/GA and subsequently given aMPV vaccine singly or in combination with La Sota were equally protected against clinical signs. Chicks that were vaccinated against NDV either once with VG/GA or followed by La Sota (singly or in combination with aMPV were fully protected when challenged with velogenic NDV. We concluded that simultaneous administration of live aMPV and NDV La Sota vaccines have no adverse effects on protection conferred by either live vaccine.

  20. Optimal vaccination scenarios against vector-borne diseases

    DEFF Research Database (Denmark)

    Græsbøll, Kaare; Enøe, Claes; Bødker, Rene

    that would increase distance between infectious and susceptible hosts. This can be done very efficiently on a regional scale if the incursion route is well specified. However as the long-range spread of midge borne disease is still poorly quantified, more robust national vaccination schemes seems preferable...

  1. An economic evaluation of vector control in the age of a dengue vaccine.

    Science.gov (United States)

    Fitzpatrick, Christopher; Haines, Alexander; Bangert, Mathieu; Farlow, Andrew; Hemingway, Janet; Velayudhan, Raman

    2017-08-01

    Dengue is a rapidly emerging vector-borne Neglected Tropical Disease, with a 30-fold increase in the number of cases reported since 1960. The economic cost of the illness is measured in the billions of dollars annually. Environmental change and unplanned urbanization are conspiring to raise the health and economic cost even further beyond the reach of health systems and households. The health-sector response has depended in large part on control of the Aedes aegypti and Ae. albopictus (mosquito) vectors. The cost-effectiveness of the first-ever dengue vaccine remains to be evaluated in the field. In this paper, we examine how it might affect the cost-effectiveness of sustained vector control. We employ a dynamic Markov model of the effects of vector control on dengue in both vectors and humans over a 15-year period, in six countries: Brazil, Columbia, Malaysia, Mexico, the Philippines, and Thailand. We evaluate the cost (direct medical costs and control programme costs) and cost-effectiveness of sustained vector control, outbreak response and/or medical case management, in the presence of a (hypothetical) highly targeted and low cost immunization strategy using a (non-hypothetical) medium-efficacy vaccine. Sustained vector control using existing technologies would cost little more than outbreak response, given the associated costs of medical case management. If sustained use of existing or upcoming technologies (of similar price) reduce vector populations by 70-90%, the cost per disability-adjusted life year averted is 2013 US$ 679-1331 (best estimates) relative to no intervention. Sustained vector control could be highly cost-effective even with less effective technologies (50-70% reduction in vector populations) and in the presence of a highly targeted and low cost immunization strategy using a medium-efficacy vaccine. Economic evaluation of the first-ever dengue vaccine is ongoing. However, even under very optimistic assumptions about a highly targeted and low

  2. An economic evaluation of vector control in the age of a dengue vaccine.

    Directory of Open Access Journals (Sweden)

    Christopher Fitzpatrick

    2017-08-01

    Full Text Available Dengue is a rapidly emerging vector-borne Neglected Tropical Disease, with a 30-fold increase in the number of cases reported since 1960. The economic cost of the illness is measured in the billions of dollars annually. Environmental change and unplanned urbanization are conspiring to raise the health and economic cost even further beyond the reach of health systems and households. The health-sector response has depended in large part on control of the Aedes aegypti and Ae. albopictus (mosquito vectors. The cost-effectiveness of the first-ever dengue vaccine remains to be evaluated in the field. In this paper, we examine how it might affect the cost-effectiveness of sustained vector control.We employ a dynamic Markov model of the effects of vector control on dengue in both vectors and humans over a 15-year period, in six countries: Brazil, Columbia, Malaysia, Mexico, the Philippines, and Thailand. We evaluate the cost (direct medical costs and control programme costs and cost-effectiveness of sustained vector control, outbreak response and/or medical case management, in the presence of a (hypothetical highly targeted and low cost immunization strategy using a (non-hypothetical medium-efficacy vaccine.Sustained vector control using existing technologies would cost little more than outbreak response, given the associated costs of medical case management. If sustained use of existing or upcoming technologies (of similar price reduce vector populations by 70-90%, the cost per disability-adjusted life year averted is 2013 US$ 679-1331 (best estimates relative to no intervention. Sustained vector control could be highly cost-effective even with less effective technologies (50-70% reduction in vector populations and in the presence of a highly targeted and low cost immunization strategy using a medium-efficacy vaccine.Economic evaluation of the first-ever dengue vaccine is ongoing. However, even under very optimistic assumptions about a highly targeted

  3. Fowl adenovirus serotype 9 vectored vaccine for protection of avian influenza virus

    Science.gov (United States)

    A fowl adenovirus serotype 9, a non-pathogenic large double stranded DNA virus, was developed as a viral vector to express influenza genes as a potential vaccine. Two separate constructs were developed that expressed either the hemagglutinin gene of A/Chicken/Jalisco/2012 (H7) or A/ Chicken/Iowa/20...

  4. Adenovirus 2, Bordetella bronchiseptica, and Parainfluenza Molecular Diagnostic Assay Results in Puppies After vaccination with Modified Live Vaccines.

    Science.gov (United States)

    Ruch-Gallie, R; Moroff, S; Lappin, M R

    2016-01-01

    Canine adenovirus 2, parainfluenza, and Bordetella bronchiseptica cause respiratory disease in dogs, and each has a modified live intranasal vaccine available. Molecular diagnostic assays to amplify specific nucleic acids are available for each of these agents. If positive molecular diagnostic assay results are common after vaccination, the positive predictive value of the diagnostic assays for disease would be decreased. To determine the impact of administration of commercially available modified live topical adenovirus 2, B. bronchiseptica, and parainfluenza vaccine has on the results of a commercially available PCR panel. Eight puppies from a research breeding facility negative for these pathogens. Blinded prospective pilot study. Puppies were vaccinated with a single dose of modified live topical adenovirus 2, B. bronchiseptica, and parainfluenza and parenteral dose of adenovirus 2, canine distemper virus, and parvovirus. Nasal and pharyngeal swabs were collected on multiple days and submitted for PCR assay. Nucleic acids of all 3 organisms contained in the topical vaccine were detected from both samples multiple times through 28 days after vaccination with higher numbers of positive samples detected between days 3 and 10 after vaccination. Vaccine status should be considered when interpreting respiratory agent PCR results if modified live vaccines have been used. Development of quantitative PCR and wild-type sequencing are necessary to improve positive predictive value of these assays by distinguishing vaccinate from natural infection. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  5. Viral Vectors for Use in the Development of Biodefense Vaccines

    Science.gov (United States)

    2005-06-17

    Shigella species Dengue Salmonella Filoviruses Listeria monocytogenes Ebola Campylobacter jejuni Marburg Yersinia entercolitica Viruses (Caliciviruses...Orthopoxvirus genus containing the monkey - J.S. Lee et al. / Advanced Drug Delivery Reviews 57 (2005) 1293–1314 1297 Approved for public release. Distribution...four monkeys vaccinated with V-LSGPC produced antibodies specific for LSV. After challenge, the four monkeys developed a febrile illness with low

  6. Live-attenuated tetravalent dengue vaccines: The needs and challenges of post-licensure evaluation of vaccine safety and effectiveness.

    Science.gov (United States)

    Wichmann, Ole; Vannice, Kirsten; Asturias, Edwin J; de Albuquerque Luna, Expedito José; Longini, Ira; Lopez, Anna Lena; Smith, Peter G; Tissera, Hasitha; Yoon, In-Kyu; Hombach, Joachim

    2017-10-09

    Since December 2015, the first dengue vaccine has been licensed in several Asian and Latin American countries for protection against disease from all four dengue virus serotypes. While the vaccine demonstrated an overall good safety and efficacy profile in clinical trials, some key research questions remain which make risk-benefit-assessment for some populations difficult. As for any new vaccine, several questions, such as very rare adverse events following immunization, duration of vaccine-induced protection and effectiveness when used in public health programs, will be addressed by post-licensure studies and by data from national surveillance systems after the vaccine has been introduced. However, the complexity of dengue epidemiology, pathogenesis and population immunity, as well as some characteristics of the currently licensed vaccine, and potentially also future, live-attenuated dengue vaccines, poses a challenge for evaluation through existing monitoring systems, especially in low and middle-income countries. Most notable are the different efficacies of the currently licensed vaccine by dengue serostatus at time of first vaccination and by dengue virus serotype, as well as the increased risk of dengue hospitalization among young vaccinated children observed three years after the start of vaccination in one of the trials. Currently, it is unknown if the last phenomenon is restricted to younger ages or could affect also seronegative individuals aged 9years and older, who are included in the group for whom the vaccine has been licensed. In this paper, we summarize scientific and methodological considerations for public health surveillance and targeted post-licensure studies to address some key research questions related to live-attenuated dengue vaccines. Countries intending to introduce a dengue vaccine should assess their capacities to monitor and evaluate the vaccine's effectiveness and safety and, where appropriate and possible, enhance their surveillance

  7. Development of a chimeric Zika vaccine using a licensed live-attenuated flavivirus vaccine as backbone.

    Science.gov (United States)

    Li, Xiao-Feng; Dong, Hao-Long; Wang, Hong-Jiang; Huang, Xing-Yao; Qiu, Ye-Feng; Ji, Xue; Ye, Qing; Li, Chunfeng; Liu, Yang; Deng, Yong-Qiang; Jiang, Tao; Cheng, Gong; Zhang, Fu-Chun; Davidson, Andrew D; Song, Ya-Jun; Shi, Pei-Yong; Qin, Cheng-Feng

    2018-02-14

    The global spread of Zika virus (ZIKV) and its unexpected association with congenital defects necessitates the rapid development of a safe and effective vaccine. Here we report the development and characterization of a recombinant chimeric ZIKV vaccine candidate (termed ChinZIKV) that expresses the prM-E proteins of ZIKV using the licensed Japanese encephalitis live-attenuated vaccine SA14-14-2 as the genetic backbone. ChinZIKV retains its replication activity and genetic stability in vitro, while exhibiting an attenuation phenotype in multiple animal models. Remarkably, immunization of mice and rhesus macaques with a single dose of ChinZIKV elicits robust and long-lasting immune responses, and confers complete protection against ZIKV challenge. Significantly, female mice immunized with ChinZIKV are protected against placental and fetal damage upon ZIKV challenge during pregnancy. Overall, our study provides an alternative vaccine platform in response to the ZIKV emergency, and the safety, immunogenicity, and protection profiles of ChinZIKV warrant further clinical development.

  8. Suitability of canine herpesvirus as a vector for oral bait vaccination of foxes.

    Science.gov (United States)

    Reubel, Gerhard H; Wright, John; Pekin, Jenny; French, Nigel; Strive, Tanja

    2006-05-31

    Studies were conducted to evaluate the feasibility of using canine herpesvirus (CHV) as a vaccine vector for bait-delivered oral vaccination of wild foxes. To test the viability of CHV in baits, CHV was freeze-dried, incorporated into different baits, stored, and the remaining viral infectivity tested in cell culture after varying periods of time at different storage temperatures. Experimental baits (mouse carcasses) and commercial baits (FOXOFF and PROBAIT) were prepared with either liquid or freeze-dried CHV and tested in two fox trials for their capacity to induce CHV-specific antibodies following oral baiting. Freeze-drying and storage temperatures below 0 degrees C had a stabilizing effect to virus infectivity. When stored at -20 degrees C, freeze-dried CHV retained its full infectivity for up to 3 months in PROBAIT baits, the remaining infectivity in FOXOFF baits was 100-fold less. Oral baiting with CHV induced antiviral serum antibodies in all vaccinated foxes (20/20). None of the vaccinated foxes became ill or shed infectious virus into the environment although viral DNA was detected in body secretions as evaluated by PCR. The results indicate that CHV can be freeze-dried and stored over extended periods of time without loosing much of its infectivity. This is the first report of CHV being used for oral bait vaccination of foxes. It appears that CHV is well suited for use as a recombinant vector for wild canids.

  9. A nonintegrative lentiviral vector-based vaccine provides long-term sterile protection against malaria.

    Directory of Open Access Journals (Sweden)

    Frédéric Coutant

    Full Text Available Trials testing the RTS,S candidate malaria vaccine and radiation-attenuated sporozoites (RAS have shown that protective immunity against malaria can be induced and that an effective vaccine is not out of reach. However, longer-term protection and higher protection rates are required to eradicate malaria from the endemic regions. It implies that there is still a need to explore new vaccine strategies. Lentiviral vectors are very potent at inducing strong immunological memory. However their integrative status challenges their safety profile. Eliminating the integration step obviates the risk of insertional oncogenesis. Providing they confer sterile immunity, nonintegrative lentiviral vectors (NILV hold promise as mass pediatric vaccine by meeting high safety standards. In this study, we have assessed the protective efficacy of NILV against malaria in a robust pre-clinical model. Mice were immunized with NILV encoding Plasmodium yoelii Circumsporozoite Protein (Py CSP and challenged with sporozoites one month later. In two independent protective efficacy studies, 50% (37.5-62.5 of the animals were fully protected (p = 0.0072 and p = 0.0008 respectively when compared to naive mice. The remaining mice with detectable parasitized red blood cells exhibited a prolonged patency and reduced parasitemia. Moreover, protection was long-lasting with 42.8% sterile protection six months after the last immunization (p = 0.0042. Post-challenge CD8+ T cells to CSP, in contrast to anti-CSP antibodies, were associated with protection (r = -0.6615 and p = 0.0004 between the frequency of IFN-g secreting specific T cells in spleen and parasitemia. However, while NILV and RAS immunizations elicited comparable immunity to CSP, only RAS conferred 100% of sterile protection. Given that a better protection can be anticipated from a multi-antigen vaccine and an optimized vector design, NILV appear as a promising malaria vaccine.

  10. DIVA vaccine properties of the live chimeric pestivirus strain CP7_E2gif

    DEFF Research Database (Denmark)

    von Rosen, Tanya; Rangelova, Desislava Yordanova; Nielsen, Jens

    2014-01-01

    Live modified vaccines to protect against classical swine fever virus (CSFV), based on chimeric pestiviruses, have been developed to enable serological Differentiation of Infected from Vaccinated Animals (DIVA). In this context, the chimeric virus CP7_E2gif vaccine candidate is unique as it does...

  11. Reversion of a live porcine reproductive and respiratory virus vaccine investigated by parallel mutations

    DEFF Research Database (Denmark)

    Nielsen, Henriette S.; Oleksiewicz, Martin B; Forsberg, R

    2001-01-01

    A live attenuated porcine reproductive and respiratory syndrome (PRRS) vaccine virus has been shown to revert to virulence under field conditions. In order to identify genetic virulence determinants, ORF1 from the attenuated vaccine virus and three Danish vaccine-derived field isolates was sequen......A live attenuated porcine reproductive and respiratory syndrome (PRRS) vaccine virus has been shown to revert to virulence under field conditions. In order to identify genetic virulence determinants, ORF1 from the attenuated vaccine virus and three Danish vaccine-derived field isolates...... in the vaccine virus sequence during cell-culture adaptation. Evaluation of the remaining mutations in the ORF1 sequence revealed stronger selective pressure for amino acid conservation during spread in pigs than during vaccine production. Furthermore, it was found that the selective pressure did not change...

  12. Reversion of a live porcine reproductive and respiratory syndrome virus vaccine investigated by parallel mutations

    DEFF Research Database (Denmark)

    Nielsen, Henriette S.; Oleksiewicz, M.B.; Forsberg, R.

    2001-01-01

    A live attenuated porcine reproductive and respiratory syndrome (PRRS) vaccine virus has been shown to revert to virulence under field conditions. In order to identify genetic virulence determinants, ORF1 from the attenuated vaccine virus and three Danish vaccine-derived field isolates was sequen......A live attenuated porcine reproductive and respiratory syndrome (PRRS) vaccine virus has been shown to revert to virulence under field conditions. In order to identify genetic virulence determinants, ORF1 from the attenuated vaccine virus and three Danish vaccine-derived field isolates...... in the vaccine virus sequence during cell-culture adaptation. Evaluation of the remaining mutations in the ORF1 sequence revealed stronger selective pressure for amino acid conservation during spread in pigs than during vaccine production. Furthermore, it was found that the selective pressure did not change...

  13. Vaccinia virus vectors: new strategies for producing recombinant vaccines.

    Science.gov (United States)

    Hruby, D E

    1990-01-01

    The development and continued refinement of techniques for the efficient insertion and expression of heterologous DNA sequences from within the genomic context of infectious vaccinia virus recombinants are among the most promising current approaches towards effective immunoprophylaxis against a variety of protozoan, viral, and bacterial human pathogens. Because of its medical relevance, this area is the subject of intense research interest and has evolved rapidly during the past several years. This review (i) provides an updated overview of the technology that exists for assembling recombinant vaccinia virus strains, (ii) discusses the advantages and disadvantages of these approaches, (iii) outlines the areas of outgoing research directed towards overcoming the limitations of current techniques, and (iv) provides some insight (i.e., speculation) about probable future refinements in the use of vaccinia virus as a vector. PMID:2187593

  14. Priming T-cell responses with recombinant measles vaccine vector in a heterologous prime-boost setting in non-human primates.

    Science.gov (United States)

    Bolton, Diane L; Santra, Sampa; Swett-Tapia, Cindy; Custers, Jerome; Song, Kaimei; Balachandran, Harikrishnan; Mach, Linh; Naim, Hussein; Kozlowski, Pamela A; Lifton, Michelle; Goudsmit, Jaap; Letvin, Norman; Roederer, Mario; Radošević, Katarina

    2012-09-07

    Licensed live attenuated virus vaccines capable of expressing transgenes from other pathogens have the potential to reduce the number of childhood immunizations by eliciting robust immunity to multiple pathogens simultaneously. Recombinant attenuated measles virus (rMV) derived from the Edmonston Zagreb vaccine strain was engineered to express simian immunodeficiency virus (SIV) Gag protein for the purpose of evaluating the immunogenicity of rMV as a vaccine vector in rhesus macaques. rMV-Gag immunization alone elicited robust measles-specific humoral and cellular responses, but failed to elicit transgene (Gag)-specific immune responses, following aerosol or intratracheal/intramuscular delivery. However, when administered as a priming vaccine to a heterologous boost with recombinant adenovirus serotype 5 expressing the same transgene, rMV-Gag significantly enhanced Gag-specific T lymphocyte responses following rAd5 immunization. Gag-specific humoral responses were not enhanced, however, which may be due to either the transgene or the vector. Cellular response priming by rMV against the transgene was highly effective even when using a suboptimal dose of rAd5 for the boost. These data demonstrate feasibility of using rMV as a priming component of heterologous prime-boost vaccine regimens for pathogens requiring strong cellular responses. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Limited infection upon human exposure to a recombinant raccoon pox vaccine vector

    Science.gov (United States)

    Rocke, T.E.; Dein, F.J.; Fuchsberger, M.; Fox, B.C.; Stinchcomb, D.T.; Osorio, J.G.

    2004-01-01

    A laboratory accident resulted in human exposure to a recombinant raccoon poxvirus (RCN) developed as a vaccine vector for antigens of Yersinia pestis for protection of wild rodents (and other animals) against plague. Within 9 days, the patient developed a small blister that healed within 4 weeks. Raccoon poxvirus was cultured from the lesion, and the patient developed antibody to plague antigen (F1) and RCN. This is the first documented case of human exposure to RCN.

  16. Limited infection upon human exposure to a recombinant raccoon pox vaccine vector.

    Science.gov (United States)

    Rocke, Tonie E; Dein, F Joshua; Fuchsberger, Martina; Fox, Barry C; Stinchcomb, Dan T; Osorio, Jorge E

    2004-07-29

    A laboratory accident resulted in human exposure to a recombinant raccoon poxvirus (RCN) developed as a vaccine vector for antigens of Yersinia pestis for protection of wild rodents (and other animals) against plague. Within 9 days, the patient developed a small blister that healed within 4 weeks. Raccoon poxvirus was cultured from the lesion, and the patient developed antibody to plague antigen (F1) and RCN. This is the first documented case of human exposure to RCN.

  17. 9 CFR 113.27 - Detection of extraneous viable bacteria and fungi in live vaccines.

    Science.gov (United States)

    2010-01-01

    ... bacteria and fungi in live vaccines. 113.27 Section 113.27 Animals and Animal Products ANIMAL AND PLANT... bacteria and fungi in live vaccines. Unless otherwise specified by the Administrator or elsewhere exempted... Seed Bacteria shall be tested for extraneous viable bacteria and fungi as prescribed in this section. A...

  18. A novel multi-antigen virally vectored vaccine against Mycobacterium avium subspecies paratuberculosis.

    Directory of Open Access Journals (Sweden)

    Tim J Bull

    Full Text Available BACKGROUND: Mycobacterium avium subspecies paratuberculosis causes systemic infection and chronic intestinal inflammation in many species including primates. Humans are exposed through milk and from sources of environmental contamination. Hitherto, the only vaccines available against Mycobacterium avium subspecies paratuberculosis have been limited to veterinary use and comprised attenuated or killed organisms. METHODS: We developed a vaccine comprising a fusion construct designated HAV, containing components of two secreted and two cell surface Mycobacterium avium subspecies paratuberculosis proteins. HAV was transformed into DNA, human Adenovirus 5 (Ad5 and Modified Vaccinia Ankara (MVA delivery vectors. Full length expression of the predicted 95 kDa fusion protein was confirmed. PRINCIPAL FINDINGS: Vaccination of naïve and Mycobacterium avium subspecies paratuberculosis infected C57BL/6 mice using DNA-prime/MVA-boost or Ad5-prime/MVA-boost protocols was highly immunogenic resulting in significant IFN-gamma ELISPOT responses by splenocytes against recombinant vaccine antigens and a range of HAV specific peptides. This included strong recognition of a T-cell epitope GFAEINPIA located near the C-terminus of the fusion protein. Antibody responses to recombinant vaccine antigens and HAV specific peptides but not GFAEINPIA, also occurred. No immune recognition of vaccine antigens occurred in any sham vaccinated Mycobacterium avium subspecies paratuberculosis infected mice. Vaccination using either protocol significantly attenuated pre-existing Mycobacterium avium subspecies paratuberculosis infection measured by qPCR in spleen and liver and the Ad5-prime/MVA-boost protocol also conferred some protection against subsequent challenge. No adverse effects of vaccination occurred in any of the mice. CONCLUSIONS/SIGNIFICANCE: A range of modern veterinary and clinical vaccines for the treatment and prevention of disease caused by Mycobacterium avium

  19. CRISPR/Cas9-Advancing Orthopoxvirus Genome Editing for Vaccine and Vector Development.

    Science.gov (United States)

    Okoli, Arinze; Okeke, Malachy I; Tryland, Morten; Moens, Ugo

    2018-01-22

    The clustered regularly interspaced short palindromic repeat (CRISPR)/associated protein 9 (Cas9) technology is revolutionizing genome editing approaches. Its high efficiency, specificity, versatility, flexibility, simplicity and low cost have made the CRISPR/Cas9 system preferable to other guided site-specific nuclease-based systems such as TALENs (Transcription Activator-like Effector Nucleases) and ZFNs (Zinc Finger Nucleases) in genome editing of viruses. CRISPR/Cas9 is presently being applied in constructing viral mutants, preventing virus infections, eradicating proviral DNA, and inhibiting viral replication in infected cells. The successful adaptation of CRISPR/Cas9 to editing the genome of Vaccinia virus paves the way for its application in editing other vaccine/vector-relevant orthopoxvirus (OPXV) strains. Thus, CRISPR/Cas9 can be used to resolve some of the major hindrances to the development of OPXV-based recombinant vaccines and vectors, including sub-optimal immunogenicity; transgene and genome instability; reversion of attenuation; potential of spread of transgenes to wildtype strains and close contacts, which are important biosafety and risk assessment considerations. In this article, we review the published literature on the application of CRISPR/Cas9 in virus genome editing and discuss the potentials of CRISPR/Cas9 in advancing OPXV-based recombinant vaccines and vectors. We also discuss the application of CRISPR/Cas9 in combating viruses of clinical relevance, the limitations of CRISPR/Cas9 and the current strategies to overcome them.

  20. CRISPR/Cas9—Advancing Orthopoxvirus Genome Editing for Vaccine and Vector Development

    Science.gov (United States)

    Okoli, Arinze; Okeke, Malachy I.; Tryland, Morten; Moens, Ugo

    2018-01-01

    The clustered regularly interspaced short palindromic repeat (CRISPR)/associated protein 9 (Cas9) technology is revolutionizing genome editing approaches. Its high efficiency, specificity, versatility, flexibility, simplicity and low cost have made the CRISPR/Cas9 system preferable to other guided site-specific nuclease-based systems such as TALENs (Transcription Activator-like Effector Nucleases) and ZFNs (Zinc Finger Nucleases) in genome editing of viruses. CRISPR/Cas9 is presently being applied in constructing viral mutants, preventing virus infections, eradicating proviral DNA, and inhibiting viral replication in infected cells. The successful adaptation of CRISPR/Cas9 to editing the genome of Vaccinia virus paves the way for its application in editing other vaccine/vector-relevant orthopoxvirus (OPXV) strains. Thus, CRISPR/Cas9 can be used to resolve some of the major hindrances to the development of OPXV-based recombinant vaccines and vectors, including sub-optimal immunogenicity; transgene and genome instability; reversion of attenuation; potential of spread of transgenes to wildtype strains and close contacts, which are important biosafety and risk assessment considerations. In this article, we review the published literature on the application of CRISPR/Cas9 in virus genome editing and discuss the potentials of CRISPR/Cas9 in advancing OPXV-based recombinant vaccines and vectors. We also discuss the application of CRISPR/Cas9 in combating viruses of clinical relevance, the limitations of CRISPR/Cas9 and the current strategies to overcome them. PMID:29361752

  1. Vector prime/protein boost vaccine that overcomes defects acquired during aging and cancer

    DEFF Research Database (Denmark)

    Tang, Y.; Akbulut, H.; Maynard, J.

    2006-01-01

    We showed that the Ad-sig-TAA/ecdCD40L vaccine induces a tumor suppressive immune response to the hMUC-1 and rH2N tumor-associated self Ags (TAA) and to the Annexin A1 tumor vascular Ag, even in mice in which anergy exists to these Ags. When the TAA/ecdCD40L protein is given s.c. as a boost...... following the Ad-sig-TAA/ecdCD40L vector, the levels of the TAA-specific CD8 T cells and Abs increase dramatically over that seen with vector alone, in young (2-mo-old) as well as old (18-mo-old) mice. The Abs induced against hMUC-1 react with human breast cancer. This vaccine also induces a 4-fold...... decrement of negative regulatory CD4CD25FOXP3-T cells in the tumor tissue of 18-mo-old mice. These results suggest that the Ad-sig-TAA/ecdCD40L vector prime-TAA/ecdCD40L protein boost vaccine platform may be valuable in reducing postsurgery recurrence in a variety of epithelial neoplasms....

  2. Immunoproteomics analysis of the murine antibody response to vaccination with an improved Francisella tularensis live vaccine strain (LVS.

    Directory of Open Access Journals (Sweden)

    Susan M Twine

    2010-04-01

    Full Text Available Francisella tularensis subspecies tularensis is the causative agent of a spectrum of diseases collectively known as tularemia. An attenuated live vaccine strain (LVS has been shown to be efficacious in humans, but safety concerns have prevented its licensure by the FDA. Recently, F. tularensis LVS has been produced under Current Good Manufacturing Practice (CGMP guidelines. Little is known about the immunogenicity of this new vaccine preparation in comparison with extensive studies conducted with laboratory passaged strains of LVS. Thus, the aim of the current work was to evaluate the repertoire of antibodies produced in mouse strains vaccinated with the new LVS vaccine preparation.In the current study, we used an immunoproteomics approach to examine the repertoire of antibodies induced following successful immunization of BALB/c versus unsuccessful vaccination of C57BL/6 mice with the new preparation of F. tularensis LVS. Successful vaccination of BALB/c mice elicited antibodies to nine identified proteins that were not recognized by antisera from vaccinated but unprotected C57BL/6 mice. In addition, the CGMP formulation of LVS stimulated a greater repertoire of antibodies following vaccination compared to vaccination with laboratory passaged ATCC LVS strain. A total of 15 immunoreactive proteins were identified in both studies, however, 16 immunoreactive proteins were uniquely reactive with sera from the new formulation of LVS.This is the first report characterising the antibody based immune response of the new formulation of LVS in the widely used murine model of tularemia. Using two mouse strains, we show that successfully vaccinated mice can be distinguished from unsuccessfully vaccinated mice based upon the repertoire of antibodies generated. This opens the door towards downselection of antigens for incorporation into tularemia subunit vaccines. In addition, this work also highlights differences in the humoral immune response to

  3. Enhancement of Mucosal Immunogenicity of Viral Vectored Vaccines by the NKT Cell Agonist Alpha-Galactosylceramide as Adjuvant

    Directory of Open Access Journals (Sweden)

    Shailbala Singh

    2014-10-01

    Full Text Available Gene-based vaccination strategies, specifically viral vectors encoding vaccine immunogens are effective at priming strong immune responses. Mucosal routes offer practical advantages for vaccination by ease of needle-free administration, and immunogen delivery at readily accessible oral/nasal sites to efficiently induce immunity at distant gut and genital tissues. However, since mucosal tissues are inherently tolerant for induction of immune responses, incorporation of adjuvants for optimal mucosal vaccination strategies is important. We report here the effectiveness of alpha-galactosylceramide (α-GalCer, a synthetic glycolipid agonist of natural killer T (NKT cells, as an adjuvant for enhancing immunogenicity of vaccine antigens delivered using viral vectors by mucosal routes in murine and nonhuman primate models. Significant improvement in adaptive immune responses in systemic and mucosal tissues was observed by including α-GalCer adjuvant for intranasal immunization of mice with vesicular stomatitis virus vector encoding the model antigen ovalbumin and adenoviral vectors expressing HIV env and Gag antigens. Activation of NKT cells in systemic and mucosal tissues along with significant increases in adaptive immune responses were observed in rhesus macaques immunized by intranasal and sublingual routes with protein or adenovirus vectored antigens when combined with α-GalCer adjuvant. These results support the utility of α-GalCer adjuvant for enhancing immunogenicity of mucosal vaccines delivered using viral vectors.

  4. Expected Net Benefit of Vaccinating Rangeland Sheep against Bluetongue Virus Using a Modified-Live versus Killed Virus Vaccine.

    Science.gov (United States)

    Munsick, Tristram R; Peck, Dannele E; Ritten, John P; Jones, Randall; Jones, Michelle; Miller, Myrna M

    2017-01-01

    Recurring outbreaks of bluetongue virus in domestic sheep of the US Intermountain West have prompted questions about the economic benefits and costs of vaccinating individual flocks against bluetongue (BT) disease. We estimate the cost of a BT outbreak on a representative rangeland sheep operation in the Big Horn Basin of the state of Wyoming using enterprise budgets and stochastic simulation. The latter accounts for variability in disease severity and lamb price, as well as uncertainty about when an outbreak will occur. We then estimate the cost of purchasing and administering a BT vaccine. Finally, we calculate expected annual net benefit of vaccinating under various outbreak intervals. Expected annual net benefit is calculated for both a killed virus (KV) vaccine and modified-live virus vaccine, using an observed price of $0.32 per dose for modified-live and an estimated price of $1.20 per dose for KV. The modified-live vaccine's expected annual net benefit has a 100% chance of being positive for an outbreak interval of 5, 10, or 20 years, and a 77% chance of being positive for a 50-year interval. The KV vaccine's expected annual net benefit has a 97% chance of being positive for a 5-year outbreak interval, and a 42% chance of being positive for a 10-year interval. A KV vaccine is, therefore, unlikely to be economically attractive to producers in areas exposed less frequently to BT disease. A modified-live vaccine, however, requires rigorous authorization before legal use can occur in Wyoming. To date, no company has requested to manufacture a modified-live vaccine for commercial use in Wyoming. The KV vaccine poses less risk to sheep reproduction and less risk of unintentional spread, both of which facilitate approval for commercial production. Yet, our results show an economically consequential tradeoff between a KV vaccine's relative safety and higher cost. Unless the purchase price is reduced below our assumed $1.20 per dose, producer adoption of a KV

  5. Compatibility of a bivalent modified-live vaccine against Bordetella bronchiseptica and CPiV, and a trivalent modified-live vaccine against CPV, CDV and CAV-2.

    Science.gov (United States)

    Jacobs, A A C; Bergman, J G H E; Theelen, R P H; Jaspers, R; Helps, J M; Horspool, L J I; Paul, G

    2007-01-13

    Eight puppies (group 1) were vaccinated once with a bivalent modified-live vaccine against infectious tracheobronchitis by the intranasal route and at the same time with an injectable trivalent vaccine against canine parvovirus, canine distemper virus and canine adenovirus; a second group of eight puppies (group 2) was vaccinated only with the intranasal bivalent vaccine, and a further eight puppies (group 3) were vaccinated only with the injectable trivalent vaccine. Three weeks later they were all challenged with wildtype Bordetella bronchiseptica and canine parainfluenza virus by the aerosol route, and their antibody responses to the five vaccine organisms were determined. Oronasal swabs were taken regularly before and after the challenge for the isolation of bacteria and viruses, and the puppies were observed for clinical signs for three weeks after the challenge. There were no significant differences in the puppies' titres against canine parvovirus, canine distemper virus and canine adenovirus type 2 between the groups vaccinated with or without the bivalent intranasal vaccine. After the challenge the mean clinical scores of the two groups vaccinated with the intranasal vaccine were nearly 90 per cent lower (P=0.001) than the mean score of the group vaccinated with only the trivalent injectable vaccine, and the puppies in this group all became culture-positive for B bronchiseptica and canine parainfluenza virus. There were only small differences between the rates of isolation of B bronchiseptica from groups 1, 2 and 3, but significantly lower yields of canine parainfluenza virus were isolated from groups 1 and 2 than from group 3.

  6. Respiratory and oral vaccination improves protection conferred by the live vaccine strain against pneumonic tularemia in the rabbit model.

    Science.gov (United States)

    Stinson, Elizabeth; Smith, Le'Kneitah P; Cole, Kelly Stefano; Barry, Eileen M; Reed, Douglas S

    2016-10-01

    Tularemia is a severe, zoonotic disease caused by a gram-negative bacterium, Francisella tularensis We have previously shown that rabbits are a good model of human pneumonic tularemia when exposed to aerosols containing a virulent, type A strain, SCHU S4. We further demonstrated that the live vaccine strain (LVS), an attenuated type B strain, extended time to death when given by scarification. Oral or aerosol vaccination has been previously shown in humans to offer superior protection to parenteral vaccination against respiratory tularemia challenge. Both oral and aerosol vaccination with LVS were well tolerated in the rabbit with only minimal fever and no weight loss after inoculation. Plasma antibody titers against F. tularensis were higher in rabbits that were vaccinated by either oral or aerosol routes compared to scarification. Thirty days after vaccination, all rabbits were challenged with aerosolized SCHU S4. LVS given by scarification extended time to death compared to mock-vaccinated controls. One orally vaccinated rabbit did survive aerosol challenge, however, only aerosol vaccination extended time to death significantly compared to scarification. These results further demonstrate the utility of the rabbit model of pneumonic tularemia in replicating what has been reported in humans and macaques as well as demonstrating the utility of vaccination by oral and respiratory routes against an aerosol tularemia challenge. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Driving vaccine innovations to improve lives and livelihoods | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2018-02-02

    Feb 2, 2018 ... Following the Livestock Vaccine Innovation Fund's first call for ... Collectively, they represent a cross-section of disciplines, diseases, and regional hot spots, ... will focus on driving innovation in livestock vaccine development.

  8. DIVA vaccine properties of the live chimeric pestivirus strain CP7_E2gif.

    Science.gov (United States)

    von Rosen, Tanya; Rangelova, Desislava; Nielsen, Jens; Rasmussen, Thomas Bruun; Uttenthal, Åse

    2014-06-04

    Live modified vaccines to protect against classical swine fever virus (CSFV), based on chimeric pestiviruses, have been developed to enable serological Differentiation of Infected from Vaccinated Animals (DIVA). In this context, the chimeric virus CP7_E2gif vaccine candidate is unique as it does not include any CSFV components. In the present study, the DIVA vaccine properties of CP7_E2gif were evaluated in comparison to the conventional live attenuated Riemser C-strain vaccine. Sera and tonsil samples obtained from pigs immunised with these two vaccines were analysed. No viral RNA was found in serum after vaccination with CP7_E2gif, whereas some serum samples from C-strain vaccinated animals were positive. In both vaccinated groups, individual viral RNA-positive tonsil samples were detected in animals euthanised between 7 and 21 days post vaccination. Furthermore, serum samples from these animals, together with archival samples from pigs vaccinated with CP7_E2gif and subsequently CSFV challenged, were analysed for specific antibodies using ELISAs and for homologous neutralising antibodies. In animals vaccinated with CP7_E2gif, neutralising antibodies were detected from day 10. However, the sera remained negative for anti-CSFV E2-specific antibodies whereas pigs vaccinated with C-strain seroconverted against CSFV by 14 days after vaccination, as determined by a CSFV-E2 specific blocking ELISA. One week after subsequent CSFV challenge, a strong anti-CSFV E2 reaction was detected in CP7_E2gif vaccinated pigs and anti-E(rns) antibodies were detected from 10 days after infection. In conclusion, CP7_E2gif has the potential to be used as a DIVA vaccine in combination with detection of anti-CSFV E2-specific antibodies. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Immunogenicity and safety of a live attenuated varicella vaccine in ...

    African Journals Online (AJOL)

    children were vaccinated, of whom 189 (44,5%) completed the study. ... varicella vaccination.. Results. The vaccine was safe and well tolerated. No local symptoms were ... of varicella (e.g. encephalitis, pneumonia, scars); inhibition of the spread of the .... intestinal disorders, respiratory infections, measles and conjunctivitis) ...

  10. Clinical development of Ebola vaccines

    Science.gov (United States)

    Sridhar, Saranya

    2015-01-01

    The ongoing outbreak of Ebola virus disease in West Africa highlighted the lack of a licensed drug or vaccine to combat the disease and has renewed the urgency to develop a pipeline of Ebola vaccines. A number of different vaccine platforms are being developed by assessing preclinical efficacy in animal models and expediting clinical development. Over 15 different vaccines are in preclinical development and 8 vaccines are now in different stages of clinical evaluation. These vaccines include DNA vaccines, virus-like particles and viral vectors such as live replicating vesicular stomatitis virus (rVSV), human and chimpanzee adenovirus, and vaccinia virus. Recently, in preliminary results reported from the first phase III trial of an Ebola vaccine, the rVSV-vectored vaccine showed promising efficacy. This review charts this rapidly advancing area of research focusing on vaccines in clinical development and discusses the future opportunities and challenges faced in the licensure and deployment of Ebola vaccines. PMID:26668751

  11. On the efficacy of malaria DNA vaccination with magnetic gene vectors.

    Science.gov (United States)

    Nawwab Al-Deen, Fatin; Ma, Charles; Xiang, Sue D; Selomulya, Cordelia; Plebanski, Magdalena; Coppel, Ross L

    2013-05-28

    We investigated the efficacy and types of immune responses from plasmid malaria DNA vaccine encoding VR1020-PyMSP119 condensed on the surface of polyethyleneimine (PEI)-coated SPIONs. In vivo mouse studies were done firstly to determine the optimum magnetic vector composition, and then to observe immune responses elicited when magnetic vectors were introduced via different administration routes. Higher serum antibody titers against PyMSP119 were observed with intraperitoneal and intramuscular injections than subcutaneous and intradermal injections. Robust IgG2a and IgG1 responses were observed for intraperitoneal administration, which could be due to the physiology of peritoneum as a major reservoir of macrophages and dendritic cells. Heterologous DNA prime followed by single protein boost vaccination regime also enhanced IgG2a, IgG1, and IgG2b responses, indicating the induction of appropriate memory immunity that can be elicited by protein on recall. These outcomes support the possibility to design superparamagnetic nanoparticle-based DNA vaccines to optimally evoke desired antibody responses, useful for a variety of diseases including malaria. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Generalized herd effects and vaccine evaluation: impact of live influenza vaccine on off-target bacterial colonisation.

    Science.gov (United States)

    Mina, Michael J

    2017-06-01

    Interactions between pathogens and commensal microbes are major contributors to health and disease. Infectious diseases however are most often considered independent, viewed within a one-host one-pathogen paradigm and, by extension, the interventions used to treat and prevent them are measured and evaluated within this same paradigm. Vaccines, especially live vaccines, by stimulating immune responses or directly interacting with other microbes can alter the environment in which they act, with effects that span across pathogen species. Live attenuated infl uenza vaccines for example, while safe, increase upper respiratory tract bacterial carriage density of important human commensal pathogens like Streptococcus pneumoniae and Staphylococcus aureus. Further, by altering the ecological niche and dynamics of phylogenetically distinct microbes within the host, vaccines may unintentionally affect transmission of non-vaccine targeted pathogens. Thus, vaccine effects may span across species and across scales, from the individual to the population level. In keeping with traditional vaccine herd-effects that indirectly protect even unvaccinated individuals by reducing population prevalence of vaccine-targeted pathogens, we call these cross-species cross-scale effects "generalized herd-effects". As opposed to traditional herd-effects, "generalized" relaxes the assumption that the effect occurs at the level of the vaccine-target pathogen and "herd effect" implies, as usual, that the effects indirectly impact the population at large, including unvaccinated bystanders. Unlike traditional herd-effects that decrease population prevalence of the vaccine-target, generalized herd-effects may decrease or increase prevalence and disease by the off-target pathogen. LAIV, for example, by increasing pneumococcal density in the upper respiratory tract of vaccine recipients, especially children, may increase pneumococcal transmission and prevalence, leading to excess pneumococcal invasive

  13. A virus vector based on Canine Herpesvirus for vaccine applications in canids.

    Science.gov (United States)

    Strive, T; Hardy, C M; Wright, J; Reubel, G H

    2007-01-31

    Canine Herpesvirus (CHV) is being developed as a virus vector for the vaccination of European red foxes. However, initial studies using recombinant CHV vaccines in foxes revealed viral attenuation and lack of antibody response to inserted foreign antigens. These findings were attributed both to inactivation of the thymidine kinase (TK) gene and excess foreign genetic material in the recombinant viral genome. In this study, we report an improved CHV-bacterial artificial chromosome (BAC) vector system designed to overcome attenuation in foxes. A non-essential region was identified in the CHV genome as an alternative insertion site for foreign genes. Replacement of a guanine/cytosine (GC)-rich intergenic region between UL21 and UL22 of CHV with a marker gene did not change growth behaviour in vitro, showing that this region is not essential for virus growth in cell culture. We subsequently produced a CHV-BAC vector with an intact TK gene in which the bacterial genes and the antigen expression cassette were inserted into this GC-rich locus. Unlike earlier constructs, the new CHV-BAC allowed self-excision of the bacterial genes via homologous recombination after transfection of BACs into cell culture. The BAC-CHV system was used to produce a recombinant virus that constitutively expressed porcine zona pellucida subunit C protein between the UL21 and UL22 genes of CHV. Complete self-excision of the bacterial genes from CHV was achieved within one round of replication whilst retaining antigen gene expression.

  14. Safety mechanism assisted by the repressor of tetracycline (SMART) vaccinia virus vectors for vaccines and therapeutics.

    Science.gov (United States)

    Grigg, Patricia; Titong, Allison; Jones, Leslie A; Yilma, Tilahun D; Verardi, Paulo H

    2013-09-17

    Replication-competent viruses, such as Vaccinia virus (VACV), are powerful tools for the development of oncolytic viral therapies and elicit superior immune responses when used as vaccine and immunotherapeutic vectors. However, severe complications from uncontrolled viral replication can occur, particularly in immunocompromised individuals or in those with other predisposing conditions. VACVs constitutively expressing interferon-γ (IFN-γ) replicate in cell culture indistinguishably from control viruses; however, they replicate in vivo to low or undetectable levels, and are rapidly cleared even in immunodeficient animals. In an effort to develop safe and highly effective replication-competent VACV vectors, we established a system to inducibly express IFN-γ. Our SMART (safety mechanism assisted by the repressor of tetracycline) vectors are designed to express the tetracycline repressor under a constitutive VACV promoter and IFN-γ under engineered tetracycline-inducible promoters. Immunodeficient SCID mice inoculated with VACVs not expressing IFN-γ demonstrated severe weight loss, whereas those given VACVs expressing IFN-γ under constitutive VACV promoters showed no signs of infection. Most importantly, mice inoculated with a VACV expressing the IFN-γ gene under an inducible promoter remained healthy in the presence of doxycycline, but exhibited severe weight loss in the absence of doxycycline. In this study, we developed a safety mechanism for VACV based on the conditional expression of IFN-γ under a tightly controlled tetracycline-inducible VACV promoter for use in vaccines and oncolytic cancer therapies.

  15. Distinction between infections with European and American/vaccine type PRRS virus after vaccination with a modified-live PRRS virus vaccine

    DEFF Research Database (Denmark)

    Bøtner, Anette; Strandbygaard, Bertel; Sørensen, K. J.

    2000-01-01

    In July 1996 a modified live Porcine reproductive and respiratory syndrome (PRRS) vaccine, based on an American (US) strain of the PRRS virus (PRRSV), was licensed in Denmark. The vaccine was licensed for use in 3-18 week old pigs, exclusively. Starting during the middle of October 1996, several...... herds who had recently begun vaccination, experienced acute PRRS-like symptoms including an increasing number of abortions and stillborn piglets and an increasing mortality in the nursing period. During the period from October 1996 until May 1997, the PRRS virus (PRRSV), identified as the vaccine....../US type of PRRSV, was isolated from fetuses, dead piglets, pleural fluids and/or lung tissues from 114 of such herds. These findings indicated the spread of the vaccine virus to non-vaccinated sows followed by transplacental infection of fetuses. Also, a number of not previously PRRSV infected and non...

  16. A pandemic influenza H1N1 live vaccine based on modified vaccinia Ankara is highly immunogenic and protects mice in active and passive immunizations.

    Directory of Open Access Journals (Sweden)

    Annett Hessel

    Full Text Available BACKGROUND: The development of novel influenza vaccines inducing a broad immune response is an important objective. The aim of this study was to evaluate live vaccines which induce both strong humoral and cell-mediated immune responses against the novel human pandemic H1N1 influenza virus, and to show protection in a lethal animal challenge model. METHODOLOGY/PRINCIPAL FINDINGS: For this purpose, the hemagglutinin (HA and neuraminidase (NA genes of the influenza A/California/07/2009 (H1N1 strain (CA/07 were inserted into the replication-deficient modified vaccinia Ankara (MVA virus--a safe poxviral live vector--resulting in MVA-H1-Ca and MVA-N1-Ca vectors. These live vaccines, together with an inactivated whole virus vaccine, were assessed in a lung infection model using immune competent Balb/c mice, and in a lethal challenge model using severe combined immunodeficient (SCID mice after passive serum transfer from immunized mice. Balb/c mice vaccinated with the MVA-H1-Ca virus or the inactivated vaccine were fully protected from lung infection after challenge with the influenza H1N1 wild-type strain, while the neuraminidase virus MVA-N1-Ca induced only partial protection. The live vaccines were already protective after a single dose and induced substantial amounts of neutralizing antibodies and of interferon-gamma-secreting (IFN-gamma CD4- and CD8 T-cells in lungs and spleens. In the lungs, a rapid increase of HA-specific CD4- and CD8 T cells was observed in vaccinated mice shortly after challenge with influenza swine flu virus, which probably contributes to the strong inhibition of pulmonary viral replication observed. In addition, passive transfer of antisera raised in MVA-H1-Ca vaccinated immune-competent mice protected SCID mice from lethal challenge with the CA/07 wild-type virus. CONCLUSIONS/SIGNIFICANCE: The non-replicating MVA-based H1N1 live vaccines induce a broad protective immune response and are promising vaccine candidates for

  17. A review of immunogenicity and tolerability of live attenuated Hepatitis A vaccine in children

    Science.gov (United States)

    Rao, Sameer; Mao, J. S.; Motlekar, Salman; Fangcheng, Zhuang; Kadhe, Ganesh

    2016-01-01

    ABSTRACT Changing epidemiology of Hepatitis A virus (HAV) has led to an increased susceptibility of adolescents and adults to the infection. Vaccination can remarkably reduce the incidence and associated morbidity of HAV infection. This review is focused on the safety and efficacy of H2 strain derived live attenuated Hepatitis A vaccine. We found the vaccine to be highly immunogenic with minimal or negligible safety issues. Moreover, a single dose of live attenuated vaccine persists a long term immune response and can be a preferred option for developing countries. In 2014, Indian Academy of Paediatrics (IAP) also updated their recommendations for H2 vaccine as a single dose as against the previous 2 dose schedule. A focused approach to include the vaccine in national immunization program should be explored. PMID:27532370

  18. Intramuscular Immunization of Mice with the Live-Attenuated Herpes Simplex Virus 1 Vaccine Strain VC2 Expressing Equine Herpesvirus 1 (EHV-1) Glycoprotein D Generates Anti-EHV-1 Immune Responses in Mice.

    Science.gov (United States)

    Liu, Shiliang A; Stanfield, Brent A; Chouljenko, Vladimir N; Naidu, Shan; Langohr, Ingeborg; Del Piero, Fabio; Ferracone, Jacqueline; Roy, Alma A; Kousoulas, Konstantin G

    2017-06-15

    Vaccination remains the best option to combat equine herpesvirus 1 (EHV-1) infection, and several different strategies of vaccination have been investigated and developed over the past few decades. Herein, we report that the live-attenuated herpes simplex virus 1 (HSV-1) VC2 vaccine strain, which has been shown to be unable to enter into neurons and establish latency in mice, can be utilized as a vector for the heterologous expression of EHV-1 glycoprotein D (gD) and that the intramuscular immunization of mice results in strong antiviral humoral and cellular immune responses. The VC2-EHV-1-gD recombinant virus was constructed by inserting an EHV-1 gD expression cassette under the control of the cytomegalovirus immediate early promoter into the VC2 vector in place of the HSV-1 thymidine kinase (UL23) gene. The vaccines were introduced into mice through intramuscular injection. Vaccination with both the VC2-EHV-1-gD vaccine and the commercially available vaccine Vetera EHV XP 1/4 (Vetera; Boehringer Ingelheim Vetmedica) resulted in the production of neutralizing antibodies, the levels of which were significantly higher in comparison to those in VC2- and mock-vaccinated animals ( P < 0.01 or P < 0.001). Analysis of EHV-1-reactive IgG subtypes demonstrated that vaccination with the VC2-EHV-1-gD vaccine stimulated robust IgG1 and IgG2a antibodies after three vaccinations ( P < 0.001). Interestingly, Vetera-vaccinated mice produced significantly higher levels of IgM than mice in the other groups before and after challenge ( P < 0.01 or P < 0.05). Vaccination with VC2-EHV-1-gD stimulated strong cellular immune responses, characterized by the upregulation of both interferon- and tumor necrosis factor-positive CD4 + T cells and CD8 + T cells. Overall, the data suggest that the HSV-1 VC2 vaccine strain may be used as a viral vector for the vaccination of horses as well as, potentially, for the vaccination of other economically important animals. IMPORTANCE A novel virus-vectored

  19. Immunogenicity and Efficacy of Live L. tarentolae Expressing KMP11-NTGP96-GFP Fusion as a Vaccine Candidate against Experimental Visceral Leishmaniasis Caused by L. infantum

    Directory of Open Access Journals (Sweden)

    Vahid NASIRI

    2016-10-01

    Full Text Available Background: The aim of present study was to evaluate the protective efficacy of live recombinant L. tarentolae expressing KMP11-NTGP96-GFP fusion as candidates for live engineered recombinant vaccine against visceral leishmaniasis in BALB/c mice.Methods: KMP-11 and NT-GP96 genes cloned into the pJET1.2/blunt cloning vector and then into pEGFP-N1 expression vector. The KMP-11, NT-GP96 and GFP fused in pEGFP-N1 and subcloned into Leishmanian pLEXSY-neo vector. Finally this construct was transferred to L. tarentolae by electroporation. Tranfection was confirmed by SDS-PAGE, WESTERN blot, flowcytometry and RT-PCR. Protective efficacy of this construct was evaluated as a vaccine candidate against visceral leishmaniasis. Parasite burden, humoral and cellular immune responses were assessed before and at 4 weeks after challenge.Results: KMP- NT-Gp96-GFP Fusion was cloned successfully into pLEXSY -neo vector and this construct successfully transferred to L. tarentolae. Finding indicated that immunization with L. tarentolae tarentolae-KMP11-NTGP96-GFP provides significant protection against visceral leishmaniasis and was able to induce an increased expression of IFN-γ and IgG2a. Following challenge, a reduced parasite load in the spleen of the KMP11-NTGP96-GFP immunized group was detected.Conclusion: The present study is the first to use a combination of a Leishmania antigen with an immunologic antigen in live recombinant L. tarentolae and results suggest that L. tarentolae-KMP11-NTGP96-GFP could be considered as a potential tool in vaccination against visceral leishmaniasis and this vaccination strategy could provide a potent rout for future vaccine development. 

  20. Long-term viremia and fecal shedding in pups after modified-live canine parvovirus vaccination.

    Science.gov (United States)

    Decaro, Nicola; Crescenzo, Giuseppe; Desario, Costantina; Cavalli, Alessandra; Losurdo, Michele; Colaianni, Maria Loredana; Ventrella, Gianpiero; Rizzi, Stefania; Aulicino, Stefano; Lucente, Maria Stella; Buonavoglia, Canio

    2014-06-24

    Canine parvovirus (CPV) modified live virus vaccines are able to infect vaccinated dogs replicating in the bloodstream and enteric mucosa. However, the exact duration and extent of CPV vaccine-induced viremia and fecal shedding are not known. With the aim to fill this gap, 26 dogs were administered two commercial vaccines containing a CPV-2 or CPV-2b strain and monitored for 28 days after vaccination. By using real-time PCR, vaccine-induced viremia and shedding were found to be long lasting for both vaccinal strains. Vaccinal CPV-2b shedding was detected for a shorter period than CPV-2 (12 against 19 mean days) but with greater viral loads, whereas viremia occurred for a longer period (22 against 19 mean days) and with higher titers for CPV-2b. Seroconversion appeared as early as 7 and 14 days post-vaccination for CPV-2b and CPV-2 vaccines, respectively. With no vaccine there was any diagnostic interference using in-clinic or hemagglutination test, since positive results were obtained only by fecal real-time PCR testing. The present study adds new insights into the CPV vaccine persistence in the organism and possible interference with diagnostic tests. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Vaccine supply chains need to be better funded and strengthened, or lives will be at risk.

    Science.gov (United States)

    Kaufmann, Judith R; Miller, Roger; Cheyne, James

    2011-06-01

    In the next decade, at least twelve additional vaccines that target such diseases as typhoid, malaria, and dengue will become available to lower- and middle-income countries. These vaccines must travel along what are called supply chains, which include all personnel, systems, equipment, and activities involved in ensuring that vaccines are effectively delivered from the point of production to the people who need them. But for various reasons, supply chains are already strained in many developing countries, and the potential inability to distribute new vaccines will place lives at risk. Among the many steps needed to strengthen the global vaccine supply chain, we suggest that the international community pursue improved coordination between organizations that donate and ship vaccines and the host-country officials who receive and distribute the vaccines, as well as better training for supply-chain managers.

  2. Molecular Characterization of Heterologous HIV-1gp120 Gene Expression Disruption in Mycobacterium bovis BCG Host Strain: A Critical Issue for Engineering Mycobacterial Based-Vaccine Vectors

    Science.gov (United States)

    Joseph, Joan; Fernández-Lloris, Raquel; Pezzat, Elías; Saubi, Narcís; Cardona, Pere-Joan; Mothe, Beatriz; Gatell, Josep Maria

    2010-01-01

    Mycobacterium bovis Bacillus Calmette-Guérin (BCG) as a live vector of recombinant bacterial vaccine is a promising system to be used. In this study, we evaluate the disrupted expression of heterologous HIV-1gp120 gene in BCG Pasteur host strain using replicative vectors pMV261 and pJH222. pJH222 carries a lysine complementing gene in BCG lysine auxotrophs. The HIV-1 gp120 gene expression was regulated by BCG hsp60 promoter (in plasmid pMV261) and Mycobacteria spp. α-antigen promoter (in plasmid pJH222). Among 14 rBCG:HIV-1gp120 (pMV261) colonies screened, 12 showed a partial deletion and two showed a complete deletion. However, deletion was not observed in all 10 rBCG:HIV-1gp120 (pJH222) colonies screened. In this study, we demonstrated that E. coli/Mycobacterial expression vectors bearing a weak promoter and lysine complementing gene in a recombinant lysine auxotroph of BCG could prevent genetic rearrangements and disruption of HIV 1gp120 gene expression, a key issue for engineering Mycobacterial based vaccine vectors. PMID:20617151

  3. Molecular Characterization of Heterologous HIV-1gp120 Gene Expression Disruption in Mycobacterium bovis BCG Host Strain: A Critical Issue for Engineering Mycobacterial Based-Vaccine Vectors

    Directory of Open Access Journals (Sweden)

    Joan Joseph

    2010-01-01

    Full Text Available Mycobacterium bovis Bacillus Calmette-Guérin (BCG as a live vector of recombinant bacterial vaccine is a promising system to be used. In this study, we evaluate the disrupted expression of heterologous HIV-1gp120 gene in BCG Pasteur host strain using replicative vectors pMV261 and pJH222. pJH222 carries a lysine complementing gene in BCG lysine auxotrophs. The HIV-1 gp120 gene expression was regulated by BCG hsp60 promoter (in plasmid pMV261 and Mycobacteria spp. α-antigen promoter (in plasmid pJH222. Among 14 rBCG:HIV-1gp120 (pMV261 colonies screened, 12 showed a partial deletion and two showed a complete deletion. However, deletion was not observed in all 10 rBCG:HIV-1gp120 (pJH222 colonies screened. In this study, we demonstrated that E. coli/Mycobacterial expression vectors bearing a weak promoter and lysine complementing gene in a recombinant lysine auxotroph of BCG could prevent genetic rearrangements and disruption of HIV 1gp120 gene expression, a key issue for engineering Mycobacterial based vaccine vectors.

  4. Live attenuated S. Typhimurium vaccine with improved safety in immuno-compromised mice.

    Directory of Open Access Journals (Sweden)

    Balamurugan Periaswamy

    Full Text Available Live attenuated vaccines are of great value for preventing infectious diseases. They represent a delicate compromise between sufficient colonization-mediated adaptive immunity and minimizing the risk for infection by the vaccine strain itself. Immune defects can predispose to vaccine strain infections. It has remained unclear whether vaccine safety could be improved via mutations attenuating a vaccine in immune-deficient individuals without compromising the vaccine's performance in the normal host. We have addressed this hypothesis using a mouse model for Salmonella diarrhea and a live attenuated Salmonella Typhimurium strain (ssaV. Vaccination with this strain elicited protective immunity in wild type mice, but a fatal systemic infection in immune-deficient cybb(-/-nos2(-/- animals lacking NADPH oxidase and inducible NO synthase. In cybb(-/-nos2(-/- mice, we analyzed the attenuation of 35 ssaV strains carrying one additional mutation each. One strain, Z234 (ssaV SL1344_3093, was >1000-fold attenuated in cybb(-/-nos2(-/- mice and ≈100 fold attenuated in tnfr1(-/- animals. However, in wt mice, Z234 was as efficient as ssaV with respect to host colonization and the elicitation of a protective, O-antigen specific mucosal secretory IgA (sIgA response. These data suggest that it is possible to engineer live attenuated vaccines which are specifically attenuated in immuno-compromised hosts. This might help to improve vaccine safety.

  5. Progress towards a Leishmania vaccine.

    Science.gov (United States)

    Tabbara, Khaled S

    2006-07-01

    Leishmaniasis is a vector-born protozoan disease. Approximately 12 million individuals are affected worldwide with an estimated annual incidence of 1.5-2 million. Two clinical manifestations are recognized, cutaneous, and visceral, both of which are common in the Middle East. In both forms, infection is chronic, with potential deformities, persistence following cure, and lifelong risk of reactivation. Attempts to develop an effective human Leishmania vaccine have not yet succeeded. Leishmanization, a crude form of live vaccination historically originated in this part of the world. Experimental vaccination has been extensively studied in model animals in the past 2 decades. In this review, major human killed vaccine trials are surveyed, and modern trends in Leishmania vaccine development, including subunit vaccines, naked DNA vaccines, and transmission blocking vaccines are explored. Recent findings of a link between persistence of live parasites, and maintenance of long-term immunity suggest live vaccination with attenuated strains, as a future vaccination strategy.

  6. Updated data on effective and safe immunizations with live-attenuated vaccines for children after living donor liver transplantation.

    Science.gov (United States)

    Shinjoh, Masayoshi; Hoshino, Ken; Takahashi, Takao; Nakayama, Tetsuo

    2015-01-29

    Although immunizations using live-attenuated vaccines are not recommended for children post-liver transplant due to their theoretical risks, they will inevitably encounter vaccine-preventable viral diseases upon returning to real-life situations. The window of opportunity for vaccination is usually limited prior to transplantation because these children often have unstable disease courses. Also, vaccine immunity does not always persist after transplantation. Beginning in 2002, subcutaneous immunizations with four individual live-attenuated vaccines (measles, rubella, varicella, and mumps) to pediatric patients following living donor liver transplantation (LDLT) were performed for those who fulfilled the clinical criteria, including humoral and cell-mediated immunity. Written informed consent was collected. We included the study on 70 immunizations for 18 cases that we reported in 2008 (Shinjoh et al., 2008). A total of 196 immunizations were administered to 48 pediatric post-LDLT recipients. Of these, 144 were first immunizations and 52 were repeated immunizations following LDLT. The seroconversion rates at the first dose for measles (AIK-C), rubella (TO-336), varicella (Oka), and mumps (Hoshino) were 100% (36/36), 100% (35/35), 70% (23/33), and 75% (24/32), respectively. Antibody levels did not fall over time in patients immunized with rubella vaccine. Three mild cases of breakthrough varicella were observed. Two cases with transient parotid gland swelling were observed after mumps immunization. Two admissions because of fever at 2-3 weeks after the measles vaccine were reported but the patients had no symptoms of measles. Immunizations using selected live-attenuated vaccines were safe and effective for post-LDLT children who were not severely immunosuppressed. However, with the exception of rubella, repeated immunization may be necessary. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Development of oral CTL vaccine using a CTP-integrated Sabin 1 poliovirus-based vector system.

    Science.gov (United States)

    Han, Seung-Soo; Lee, Jinjoo; Jung, Yideul; Kang, Myeong-Ho; Hong, Jung-Hyub; Cha, Min-Suk; Park, Yu-Jin; Lee, Ezra; Yoon, Cheol-Hee; Bae, Yong-Soo

    2015-09-11

    We developed a CTL vaccine vector by modification of the RPS-Vax system, a mucosal vaccine vector derived from a poliovirus Sabin 1 strain, and generated an oral CTL vaccine against HIV-1. A DNA fragment encoding a cytoplasmic transduction peptide (CTP) was integrated into the RPS-Vax system to generate RPS-CTP, a CTL vaccine vector. An HIV-1 p24 cDNA fragment was introduced into the RPS-CTP vector system and a recombinant poliovirus (rec-PV) named vRPS-CTP/p24 was produced. vRPS-CTP/p24 was genetically stable and efficiently induced Th1 immunity and p24-specific CTLs in immunized poliovirus receptor-transgenic (PVR-Tg) mice. In challenge experiments, PVR-Tg mice that were pre-immunized orally with vRPS-CTP/p24 were resistant to challenge with a lethal dose of p24-expressing recombinant vaccinia virus (rMVA-p24). These results suggested that the RPS-CTP vector system had potential for developing oral CTL vaccines against infectious diseases. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Titration of individual strains in trivalent live-attenuated influenza vaccine without neutralization.

    Science.gov (United States)

    Sirinonthanawech, Naraporn; Surichan, Somchaiya; Namsai, Aphinya; Puthavathana, Pilaipan; Auewarakul, Prasert; Kongchanagul, Alita

    2016-11-01

    Formulation and quality control of trivalent live-attenuated influenza vaccine requires titration of infectivity of individual strains in the trivalent mix. This is usually performed by selective neutralization of two of the three strains and titration of the un-neutralized strain in cell culture or embryonated eggs. This procedure requires standard sera with high neutralizing titer against each of the three strains. Obtaining standard sera, which can specifically neutralize only the corresponding strain of influenza viruses and is able to completely neutralize high concentration of virus in the vaccine samples, can be a problem for many vaccine manufacturers as vaccine stocks usually have very high viral titers and complete neutralization may not be obtained. Here an alternative approach for titration of individual strain in trivalent vaccine without the selective neutralization is presented. This was done by detecting individual strains with specific antibodies in an end-point titration of a trivalent vaccine in cell culture. Similar titers were observed in monovalent and trivalent vaccines for influenza A H3N2 and influenza B strains, whereas the influenza A H1N1 strain did not grow well in cell culture. Viral interference among the vaccine strains was not observed. Therefore, providing that vaccine strains grow well in cell culture, this assay can reliably determine the potency of individual strains in trivalent live-attenuated influenza vaccines. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. IMMUNO-MODULATORY EFFECT OF INACTIVATED EIMERIA TENELLA VACCINE AND LIVE IMPPORTED COCCIDIAL VACCINE ON NEWCASTLE DISEASE VIRUS VACCINA TED BROILER CHICKS

    Directory of Open Access Journals (Sweden)

    Muhammad Akram Muneer, Haji Ahmad Hashmi, Masood Rabbani, Zahid Munir Chaudhry and Ali M. Bahrami

    2001-01-01

    Full Text Available A total of 160 one-day-old broiler chicks were used to evaluate the immunomodulatory effects of an inactivated Eimeria tenella vaccine and a live polyvalent imported antiococcidial vaccine (Coccivac. This study indicated that both of these vaccines did not adversely affect the development of serum antibody against Newcastle disease virus (NDV and the chicks vaccinated with either of the anticoccidial vaccines resisted the virulent NDV challenge. A study of the lymphoid organs such as bursa of fabricuis: thymus and spleen from the experimental chicks indicated that those organs were comparable with those from the chicks not vaccinated with these coccidial vaccines. The overall findings of this study indicate that anticoccidial vaccines do not have any effects on the immune functions of the vaccinates. In fact these vaccines prevented the occurrence of clinical coccidiosis in the vaccinates.

  10. Efficacy, Safety, and Interactions of a Live Infectious Bursal Disease Virus Vaccine for Chickens Based on Strain IBD V877.

    Science.gov (United States)

    Geerligs, Harm J; Ons, Ellen; Boelm, Gert Jan; Vancraeynest, Dieter

    2015-03-01

    Infectious bursal disease (IBD) is a highly contagious disease in young chickens which can result in high morbidity and mortality and also in great economic losses. The main target for the virus is the lymphoid tissue with a special predilection for the bursa of Fabricius. Several vaccines are available to control the disease. Intermediate plus vaccines are used in chickens with high maternal antibody titers which face high infection pressure. An example of an intermediate plus vaccine is a live vaccine based on IBD strain V877. The results of an efficacy study in commercial broilers with different levels of maternally derived antibodies (MDA) showed that the V877-based IBD vaccine can break through maternal antibody titers of higher than 1100 as determined by an IBD ELISA. The safety of the vaccine was demonstrated in a study in which specific-pathogen-free (SPF) chickens were vaccinated with a tenfold dose of the vaccine strain and a tenfold dose of the vaccine strain after five back passages in SPF chickens. The vaccine virus caused lesions, as could be expected for an intermediate plus vaccine, but the scores were not much higher than the maximal scores allowed for mild IBD vaccines in the European Pharmacopoeia, and reversion to virulence was absent. In studies in SPF chickens, there were no negative impacts by the IBD V877 vaccine on the efficacy of a live QX-like IB vaccine and a live Newcastle disease La Sota vaccine in vaccination challenge studies, although the IBD vaccine had a negative effect on the antibody response generated by the QX-like IB vaccine. It is concluded that the IBD V877 vaccine has the capacity to break through high levels of MDA, has a satisfactory safety profile, and interactions with other live vaccines are limited. In order to limit bursal lesions after vaccination it is recommended to confirm the presence of MDA before vaccinating with the V877 vaccine.

  11. Listeria-vectored vaccine expressing the Mycobacterium tuberculosis 30 kDa major secretory protein via the constitutively active prfA* regulon boosts BCG efficacy against tuberculosis.

    Science.gov (United States)

    Jia, Qingmei; Dillon, Barbara Jane; Masleša-Galić, Saša; Horwitz, Marcus A

    2017-06-19

    A potent vaccine against tuberculosis, one of the world's deadliest diseases, is needed to enhance the immunity of people worldwide, most of whom have been vaccinated with the partially effective BCG vaccine. Here we investigate novel live attenuated recombinant Listeria monocytogenes (rLm) vaccines expressing the Mycobacterium tuberculosis (Mtb) 30 kDa major secretory protein (r30/Ag85B) (rLm30) as heterologous booster vaccines in animals primed with BCG. Using three attenuated Lm vectors, rLm Δ actA (LmI), rLm Δ actA Δ inlB (LmII), and rLm Δ actA Δ inlB prfA * (LmIII), we constructed five rLm30 vaccine candidates expressing the r30 linked in-frame to the Lm Listeriolycin O signal sequence and driven by the hly promoter (h30) or linked in-frame to the ActA N-terminus and driven by the actA promoter (a30). All five rLm30 vaccines secreted r30 in broth and macrophages; while rLm expressing r30 via a constitutively active prfA * regulon (rLmIII/a30) expressed the greatest amount of r30 in broth culture, all five rLm vaccines expressed equivalent amounts of r30 in infected macrophages. In comparative studies, boosting BCG-immunized mice with rLmIII/a30 induced the strongest antigen-specific T-cell responses, including splenic and lung polyfunctional CD4+ T-cells expressing the three cytokines of interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), and interleukin-2 (IL-2) ( P vaccines were generally more potent booster vaccines than r30 in adjuvant and a recombinant adenovirus vaccine expressing r30. In a setting in which BCG alone was highly immunoprotective, boosting mice with rLmIII/a30, the most potent of the vaccines, significantly enhanced protection against aerosolized Mtb ( P <0.01). Copyright © 2017 American Society for Microbiology.

  12. Improved influenza viral vector based Brucella abortus vaccine induces robust B and T-cell responses and protection against Brucella melitensis infection in pregnant sheep and goats

    Science.gov (United States)

    Mailybayeva, Aigerim; Yespembetov, Bolat; Ryskeldinova, Sholpan; Zinina, Nadezhda; Sansyzbay, Abylai; Renukaradhya, Gourapura J.; Petrovsky, Nikolai

    2017-01-01

    We previously developed a potent candidate vaccine against bovine brucellosis caused by Brucella abortus using the influenza viral vector expressing Brucella Omp16 and L7/L12 proteins (Flu-BA). Our success in the Flu-BA vaccine trial in cattle and results of a pilot study in non-pregnant small ruminants prompted us in the current study to test its efficacy against B. melitensis infection in pregnant sheep and goats. In this study, we improved the Flu-BA vaccine formulation and immunization method to achieve maximum efficacy and safety. The Flu-BA vaccine formulation had two additional proteins Omp19 and SOD, and administered thrice with 20% Montanide Gel01 adjuvant, simultaneously by both subcutaneous and conjunctival routes at 21 days intervals in pregnant sheep and goats. At 42 days post-vaccination (DPV) we detected antigen-specific IgG antibodies predominantly of IgG2a isotype but also IgG1, and also detected a strong lymphocyte recall response with IFN-γ production. Importantly, our candidate vaccine prevented abortion in 66.7% and 77.8% of pregnant sheep and goats, respectively. Furthermore, complete protection (absence of live B. melitensis 16M) was observed in 55.6% and 66.7% of challenged sheep and goats, and 72.7% and 90.0% of their fetuses (lambs/yeanlings), respectively. The severity of B. melitensis 16M infection in vaccinated sheep and goats and their fetuses (index of infection and rates of Brucella colonization in tissues) was significantly lower than in control groups. None of the protection parameters after vaccination with Flu-BA vaccine were statistically inferior to protection seen with the commercial B. melitensis Rev.1 vaccine (protection against abortion and vaccination efficacy, alpha = 0.18–0.34, infection index, P = 0.37–0.77, Brucella colonization, P = 0.16 to P > 0.99). In conclusion, our improved Flu-BA vaccine formulation and delivery method were found safe and effective in protecting pregnant sheep and goats against adverse

  13. Systems Biology of Immune Response to Live and Inactivated Dengue Virus Vaccines

    Science.gov (United States)

    2017-09-01

    AWARD NUMBER: W81XWH-16-2-0032 TITLE: Systems Biology of Immune Response to Live and Inactivated Dengue Virus Vaccines PRINCIPAL INVESTIGATOR...CONTRACT NUMBER Systems Biology of Immune Response to Live and Inactivated Dengue Virus Vaccines 5b. GRANT NUMBER W81XWH-16-2-0032 5c. PROGRAM ELEMENT...cell) responses will be measured using molecular and cellular approaches and the data analyzed using a systems biology approach. During the first

  14. Systems Biology of the Immune Response to Live and Inactivated Dengue Virus Vaccines

    Science.gov (United States)

    2017-09-01

    AWARD NUMBER: W81XWH-16-2-0031 TITLE: Systems Biology of the Immune Response to Live and Inactivated Dengue Virus Vaccines PRINCIPAL...SUBTITLE 5a. CONTRACT NUMBER Systems Biology of the Immune Response to Live and Inactivated Dengue Virus Vaccines 5b. GRANT NUMBER W81XWH-16-2-0031 5c...adaptive (T and B cell) responses will be measured using molecular and cellular approaches and the data analyzed using a systems biology approach

  15. Safety and immunogenicity of adenovirus-vectored near-consensus HIV type 1 clade B gag vaccines in healthy adults.

    Science.gov (United States)

    Harro, Clayton D; Robertson, Michael N; Lally, Michelle A; O'Neill, Lori D; Edupuganti, Srilatha; Goepfert, Paul A; Mulligan, Mark J; Priddy, Frances H; Dubey, Sheri A; Kierstead, Lisa S; Sun, Xiao; Casimiro, Danilo R; DiNubile, Mark J; Shiver, John W; Leavitt, Randi Y; Mehrotra, Devan V

    2009-01-01

    Vaccines inducing pathogen-specific cell-mediated immunity are being developed using attenuated adenoviral (Ad) vectors. We report the results of two independent Phase I trials of similar replication-deficient Ad5 vaccines containing a near-consensus HIV-1 clade B gag transgene. Healthy HIV-uninfected adults were enrolled in two separate, multicenter, dose-escalating, blinded, placebo-controlled studies to assess the safety and immunogenicity of a three-dose homologous regimen of Ad5 and MRKAd5 HIV-1 gag vaccines given on day 1, week 4, and week 26. Adverse events were collected for 29 days following each intradeltoid injection. The primary immunogenicity endpoint was the proportion of subjects with a positive unfractionated Gag-specific IFN-gamma ELISPOT response measured 4 weeks after the last dose (week 30). Analyses were performed after combining data for each dose group from both protocols, stratifying by baseline Ad5 titers. Overall, 252 subjects were randomized to receive either vaccine or placebo, including 229 subjects (91%) who completed the study through week 30. Tolerability and immunogenicity did not appear to differ between the Ad5 and MRKAd5 vaccines. The frequency of injection-site reactions was dose dependent. Systemic adverse events were also dose dependent and more frequent in subjects with baseline Ad5 titers or =200, especially after the first dose. The percent of ELISPOT responders and the ELISPOT geometric means overall were significantly higher for all four vaccine doses studied compared to placebo, and were generally higher in vaccine recipients with baseline Ad5 titers or = 200. Ad5 titers increased after vaccination in a dose-dependent fashion. Both Ad5-vectored HIV-1 vaccines were generally well tolerated and induced cell-mediated immune responses against HIV Gag-peptides in the majority of healthy adults with baseline Ad5 titers vaccine-induced immunity to the Ad5 vector may dampen the CMI response to HIV Gag.

  16. Faecal shedding of canine parvovirus after modified-live vaccination in healthy adult dogs.

    Science.gov (United States)

    Freisl, M; Speck, S; Truyen, U; Reese, S; Proksch, A-L; Hartmann, K

    2017-01-01

    Since little is known about the persistence and faecal shedding of canine parvovirus (CPV) in dogs after modified-live vaccination, diagnostic tests for CPV can be difficult to interpret in the post-vaccination period. The primary aim of this study was to determine the incidence, duration and extent of CPV vaccine virus shedding in adult dogs and to investigate related factors, including the presence of protective antibodies, increase in anti-CPV antibody titres and development of any gastrointestinal side-effects. A secondary objective was to assess prevalence of CPV field virus shedding in clinically healthy dogs due to subclinical infections. One hundred adult, healthy privately owned dogs were vaccinated with a commercial CPV-2 modified-live vaccine (MLV). Faeces were tested for the presence of CPV DNA on days 0 (prior to vaccination), 3, 7, 14, 21 and 28 by quantitative real-time PCR. Pre- and post-vaccination serum titres were determined by haemagglutination inhibition on days 0, 7 and 28. Transient excretion of CPV DNA was detected in 2.0% of dogs before vaccination. About one quarter of dogs (23.0%) shed CPV DNA during the post-vaccination period, but field and vaccine virus differentiation by VP2 gene sequencing was only successful in few samples. Faecal CPV excretion occurred despite protective serum antibody titres. Post-vaccination CPV shedding was not related to adequate antibody response after vaccination or to the occurrence of gastrointestinal side-effects. Despite individual differences, CPV DNA was detectable for up to 28 days after vaccination, although the faecal CPV DNA load in these clinically healthy dogs was very low. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Langerin negative dendritic cells promote potent CD8+ T-cell priming by skin delivery of live adenovirus vaccine microneedle arrays.

    Science.gov (United States)

    Bachy, Veronique; Hervouet, Catherine; Becker, Pablo D; Chorro, Laurent; Carlin, Leo M; Herath, Shanthi; Papagatsias, Timos; Barbaroux, Jean-Baptiste; Oh, Sea-Jin; Benlahrech, Adel; Athanasopoulos, Takis; Dickson, George; Patterson, Steven; Kwon, Sung-Yun; Geissmann, Frederic; Klavinskis, Linda S

    2013-02-19

    Stabilization of virus protein structure and nucleic acid integrity is challenging yet essential to preserve the transcriptional competence of live recombinant viral vaccine vectors in the absence of a cold chain. When coupled with needle-free skin delivery, such a platform would address an unmet need in global vaccine coverage against HIV and other global pathogens. Herein, we show that a simple dissolvable microneedle array (MA) delivery system preserves the immunogenicity of vaccines encoded by live recombinant human adenovirus type 5 (rAdHu5). Specifically, dried rAdHu5 MA immunization induced CD8(+) T-cell expansion and multifunctional cytokine responses equipotent with conventional injectable routes of immunization. Intravital imaging demonstrated MA cargo distributed both in the epidermis and dermis, with acquisition by CD11c(+) dendritic cells (DCs) in the dermis. The MA immunizing properties were attributable to CD11c(+) MHCII(hi) CD8α(neg) epithelial cell adhesion molecule (EpCAM(neg)) CD11b(+) langerin (Lang; CD207)(neg) DCs, but neither Langerhans cells nor Lang(+) DCs were required for CD8(+) T-cell priming. This study demonstrates an important technical advance for viral vaccine vectors progressing to the clinic and provides insights into the mechanism of CD8(+) T-cell priming by live rAdHu5 MAs.

  18. Pre-Clinical Efficacy and Safety of Experimental Vaccines Based on Non-Replicating Vaccinia Vectors against Yellow Fever

    Science.gov (United States)

    Schäfer, Birgit; Holzer, Georg W.; Joachimsthaler, Alexandra; Coulibaly, Sogue; Schwendinger, Michael; Crowe, Brian A.; Kreil, Thomas R.; Barrett, P. Noel; Falkner, Falko G.

    2011-01-01

    Background Currently existing yellow fever (YF) vaccines are based on the live attenuated yellow fever virus 17D strain (YFV-17D). Although, a good safety profile was historically attributed to the 17D vaccine, serious adverse events have been reported, making the development of a safer, more modern vaccine desirable. Methodology/Principal Findings A gene encoding the precursor of the membrane and envelope (prME) protein of the YFV-17D strain was inserted into the non-replicating modified vaccinia virus Ankara and into the D4R-defective vaccinia virus. Candidate vaccines based on the recombinant vaccinia viruses were assessed for immunogenicity and protection in a mouse model and compared to the commercial YFV-17D vaccine. The recombinant live vaccines induced γ-interferon-secreting CD4- and functionally active CD8-T cells, and conferred full protection against lethal challenge already after a single low immunization dose of 105 TCID50. Surprisingly, pre-existing immunity against wild-type vaccinia virus did not negatively influence protection. Unlike the classical 17D vaccine, the vaccinia virus-based vaccines did not cause mortality following intracerebral administration in mice, demonstrating better safety profiles. Conclusions/Significance The non-replicating recombinant YF candidate live vaccines induced a broad immune response after single dose administration, were effective even in the presence of a pre-existing immunity against vaccinia virus and demonstrated an excellent safety profile in mice. PMID:21931732

  19. Pre-clinical efficacy and safety of experimental vaccines based on non-replicating vaccinia vectors against yellow fever.

    Directory of Open Access Journals (Sweden)

    Birgit Schäfer

    Full Text Available BACKGROUND: Currently existing yellow fever (YF vaccines are based on the live attenuated yellow fever virus 17D strain (YFV-17D. Although, a good safety profile was historically attributed to the 17D vaccine, serious adverse events have been reported, making the development of a safer, more modern vaccine desirable. METHODOLOGY/PRINCIPAL FINDINGS: A gene encoding the precursor of the membrane and envelope (prME protein of the YFV-17D strain was inserted into the non-replicating modified vaccinia virus Ankara and into the D4R-defective vaccinia virus. Candidate vaccines based on the recombinant vaccinia viruses were assessed for immunogenicity and protection in a mouse model and compared to the commercial YFV-17D vaccine. The recombinant live vaccines induced γ-interferon-secreting CD4- and functionally active CD8-T cells, and conferred full protection against lethal challenge already after a single low immunization dose of 10(5 TCID(50. Surprisingly, pre-existing immunity against wild-type vaccinia virus did not negatively influence protection. Unlike the classical 17D vaccine, the vaccinia virus-based vaccines did not cause mortality following intracerebral administration in mice, demonstrating better safety profiles. CONCLUSIONS/SIGNIFICANCE: The non-replicating recombinant YF candidate live vaccines induced a broad immune response after single dose administration, were effective even in the presence of a pre-existing immunity against vaccinia virus and demonstrated an excellent safety profile in mice.

  20. Virus detection by PCR following vaccination of naive calves with intranasal or injectable multivalent modified-live viral vaccines.

    Science.gov (United States)

    Walz, Paul H; Newcomer, Benjamin W; Riddell, Kay P; Scruggs, Daniel W; Cortese, Victor S

    2017-09-01

    We evaluated duration of PCR-positive results following administration of modified-live viral (MLV) vaccines to beef calves. Twenty beef calves were randomly assigned to either group 1 and vaccinated intranasally with a MLV vaccine containing bovine alphaherpesvirus 1 (BoHV-1), bovine respiratory syncytial virus (BRSV), and bovine parainfluenza virus 3 (BPIV-3), or to group 2 and vaccinated subcutaneously with a MLV vaccine containing bovine viral diarrhea virus 1 and 2 (BVDV-1, -2), BoHV-1, BRSV, and BPIV-3. Deep nasopharyngeal swabs (NPS) and transtracheal washes (TTW) were collected from all calves, and whole blood was collected from group 2 calves and tested by PCR. In group 1, the proportions of calves that tested PCR-positive to BVDV, BoHV-1, BRSV, and BPIV-3 on any sample at any time were 0%, 100%, 100%, and 10%, respectively. In group 1 calves, 100% of calves became PCR-positive for BoHV-1 by day 3 post-vaccination and 100% of calves became PCR-positive for BRSV by day 7 post-vaccination. In group 2, the proportions of calves that tested positive to BVDV, BoHV-1, BRSV, and BPIV-3 on any sample at any time were 50%, 40%, 10%, and 0%, respectively. All threshold cycle (Ct) values were >30 in group 2 calves, irrespective of virus; however, Ct values PCR-positive results for BoHV-1 and BRSV. All calves were PCR-negative for all viruses after day 28. Following intranasal MLV viral vaccination, PCR results and Ct values for BRSV and BoHV-1 suggest that attempts to differentiate vaccine virus from natural infection is unreliable.

  1. Development of an attenuated live heartwater vaccine for use in ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... it requires ultra-cold storage (-196° C), intravenous administration by veterinary health professionals, ... It is expected that by the end of the project, the production process of the new heartwater vaccine will ... Agricultural Research Council.

  2. Comparison of the Effectiveness of Trivalent Inactivated Influenza Vaccine and Live, Attenuated Influenza Vaccine in Preventing Influenza-Like Illness among US Service Members, 2006-2009

    Science.gov (United States)

    2012-11-26

    controlled studies. Vaccine 2012; 30:886–92. 11. Piedra PA, Gaglani MJ, Kozinetz CA, et al. Trivalent live attenuated intranasal influenza vaccine...120:e553–64. 12. Halloran ME, Piedra PA, Longini IM Jr, et al. Efficacy of trivalent, cold-adapted, influenza virus vaccine against influenza A (Fujian

  3. Sustainable coccidiosis control in poultry production: the role of live vaccines.

    Science.gov (United States)

    Chapman, H D; Cherry, T E; Danforth, H D; Richards, G; Shirley, M W; Williams, R B

    2002-05-01

    The development of new methods of administering coccidiosis vaccines has facilitated their use in the hatchery and thereby improved prospects for the economic vaccination of broilers. The acquisition of protective immunity to Eimeria species is boosted by further exposure to infection after vaccination. Factors that affect the reproductive efficiency of non-attenuated and attenuated vaccines are considered and the key role that oocyst production plays in establishing and maintaining uniform immunity in a flock of chickens is discussed. In addition to immunisation, a possible advantage to the application of certain vaccines is that their use could repopulate poultry houses with drug-sensitive organisms. Theoretical rotation programmes in which the use of drugs is alternated with that of vaccines are described. Variability of the cross-protective immune response between strains of the same species should be considered during vaccine development and subsequent use. The significance of less common species of Eimeria, not included in all vaccines, also needs to be assessed. An important consideration is the occurrence of pathogens other than Eimeria (such as the bacterium Clostridium) in flocks given coccidiosis vaccines and the methods by which they might be controlled. More research is required into the relationship between bacterial and viral infections of poultry and coccidiosis vaccination. Vaccines need to be developed that are simple to apply and cost effective for use in areas of the world where small-scale poultry production is commonplace. In the near future it is likely that more live vaccines based upon oocysts derived from attenuated strains of Eimeria will be developed but in the longer term vaccines will be based on the selective presentation to the host of specific molecules that can induce protective immunity. This achievement will require significant investment from the private and public sectors, and, if successful, will facilitate the sustainable

  4. An effective AIDS vaccine based on live attenuated vesicular stomatitis virus recombinants.

    Science.gov (United States)

    Rose, N F; Marx, P A; Luckay, A; Nixon, D F; Moretto, W J; Donahoe, S M; Montefiori, D; Roberts, A; Buonocore, L; Rose, J K

    2001-09-07

    We developed an AIDS vaccine based on attenuated VSV vectors expressing env and gag genes and tested it in rhesus monkeys. Boosting was accomplished using vectors with glycoproteins from different VSV serotypes. Animals were challenged with a pathogenic AIDS virus (SHIV89.6P). Control monkeys showed a severe loss of CD4+ T cells and high viral loads, and 7/8 progressed to AIDS with an average time of 148 days. All seven vaccinees were initially infected with SHIV89.6P but have remained healthy for up to 14 months after challenge with low or undetectable viral loads. Protection from AIDS was highly significant (p = 0.001). VSV vectors are promising candidates for human AIDS vaccine trials because they propagate to high titers and can be delivered without injection.

  5. A potent Brucella abortus 2308 Δery live vaccine allows for the differentiation between natural and vaccinated infection.

    Science.gov (United States)

    Zhang, Junbo; Yin, Shuanghong; Guo, Fei; Meng, Ren; Chen, Chuangfu; Zhang, Hui; Li, Zhiqiang; Fu, Qiang; Shi, Huijun; Hu, Shengwei; Ni, Wei; Li, Tiansen; Zhang, Ke

    2014-08-01

    Brucellosis is a globally distributed zoonotic disease that causes animal and human diseases. However, the current Brucella abortus vaccines (S19 and RB51) are deficient; they can cause abortion in pregnant animals. Moreover, when the vaccine S19 is used, tests cannot differentiate natural from vaccinated infection. Therefore, a safer and more potent vaccine is needed. A Brucella abortus 2308 ery promoter mutant (Δery) was constructed to overcome these drawbacks. The growth of the Δery mutant was significantly attenuated in macrophages and mice and induced high protective immunity in mice. Moreover, Δery induced an anti-Brucella-specific IgG (immunoglobulin G) response and stimulated the expression of interferon-gamma (INF-γ) and interleukin-4 (IL-4). Furthermore, the expression of EryA antigen allowed for the serological differentiation between natural and vaccinated infection in mice. These results indicate that the Δery mutant is a potential attenuated live vaccine candidate against virulent Brucella abortus 2308 (S2308) infection.

  6. Safety and immunogenicity of a live attenuated mumps vaccine

    Science.gov (United States)

    Liang, Yan; Ma, Jingchen; Li, Changgui; Chen, Yuguo; Liu, Longding; Liao, Yun; Zhang, Ying; Jiang, Li; Wang, Xuan-Yi; Che, Yanchun; Deng, Wei; Li, Hong; Cui, Xiaoyu; Ma, Na; Ding, Dong; Xie, Zhongping; Cui, Pingfang; Ji, Qiuyan; Wang, Jingjing; Zhao, Yuliang; Wang, Junzhi; Li, Qihan

    2014-01-01

    Background: Mumps, a communicable, acute and previously well-controlled disease, has had recent and occasional resurgences in some areas. Methods: A randomized, double-blind, controlled and multistep phase I study of an F-genotype attenuated mumps vaccine produced in human diploid cells was conducted. A total of 300 subjects were enrolled and divided into 4 age groups: 16–60 years, 5–16 years, 2–5 years and 8–24 months. The groups were immunized with one injection per subject. Three different doses of the F-genotype attenuated mumps vaccine, A (3.5 ± 0.25 logCCID50), B (4.25 ± 0.25 logCCID50) and C (5.0 ± 0.25 logCCID50), as well as a placebo control and a positive control of a licensed A-genotype vaccine (S79 strain) were used. The safety and immunogenicity of this vaccine were compared with those of the controls. Results: The safety evaluation suggested that mild adverse reactions were observed in all groups. No serious adverse event (SAE) was reported throughout the trial. The immunogenicity test showed a similar seroconversion rate of the neutralizing and ELISA antibody in the 2- to 5-year-old and 8- to 24-month-old groups compared with the seroconversion rate in the positive control. The GMT of the neutralizing anti-F-genotype virus antibodies in the vaccine groups was slightly higher than that in the positive control group. Conclusions: The F-genotype attenuated mumps vaccine evaluated in this clinical trial was demonstrated to be safe and have effective immunogenicity vs. control. PMID:24614759

  7. Protection against California 2002 NDV strain afforded by adenovirus vectored vaccine expressing Fusion or Hemagglutination-neuraminidase genes

    Science.gov (United States)

    Vectored vaccines expressing the combination of the hemagglutinin-neuraminidase (HN) and fusion (F) genes generally have better clinical protection against Newcastle disease virus (NDV) than when either the F and HN genes are expressed alone. Interestingly, the protection induced by F is usually bet...

  8. CANINE DISTEMPER VIRUS ANTIBODY TITERS IN DOMESTIC CATS AFTER DELIVERY OF A LIVE ATTENUATED VIRUS VACCINE.

    Science.gov (United States)

    Ramsay, Edward; Sadler, Ryan; Rush, Robert; Seimon, Tracie; Tomaszewicz, Ania; Fleetwood, Ellen A; McAloose, Denise; Wilkes, Rebecca P

    2016-06-01

    Three methods for delivering a live attenuated canine distemper virus (CDV) vaccine to domestic cats ( Felis catus ) were investigated, as models for developing vaccination protocols for tigers (Panthera tigris). Twenty domestic cats were randomly divided into four treatment groups: saline injection (negative controls); and oral, intranasal, and subcutaneous vaccinates. Cats were injected with saline or a CDV vaccine (Nobivac DP, Merck) at wk 0 and 4. Blood and nasal swabs were collected at wk 0 (prior to the initial vaccination) and weekly thereafter for 9 wk. Urine samples were collected on wk 1 to 9 after initial vaccination. Forty-nine weeks following the initial vaccination series, three cats from the subcutaneous group and three cats from the intranasal group were revaccinated. Blood was collected immediately prior, and 7 and 21 days subsequent to revaccination. Nasal swabs and urine samples were collected from each cat prior to wk 49 revaccination and daily for 7 days thereafter. Nasal swabs and urine were analyzed by quantitative PCR for vaccine virus presence. Sera were tested for CDV antibodies by virus neutralization. All cats were sero-negative for CDV antibodies at the beginning of the study, and saline-injected cats remained sero-negative throughout the study. A dramatic anamnestic response was seen following wk 4 subcutaneous vaccinations, with titers peaking at wk 6 (geometric mean = 2,435.5). Following wk 49 revaccination, subcutaneous vaccinates again mounted impressive titers (wk 52 geometric mean = 2,048). Revaccination of the intranasal group cats at wk 49 produced a small increase in titers (wk 52 geometric mean = 203). CDV viral RNA was detected in six nasal swabs but no urine samples, demonstrating low viral shedding postvaccination. The strong antibody response to subcutaneous vaccination and the lack of adverse effects suggest this vaccine is safe and potentially protective against CDV infection in domestic cats.

  9. Cytomegalovirus and immunotherapy: opportunistic pathogen, novel target for cancer and a promising vaccine vector.

    Science.gov (United States)

    Quinn, Michael; Erkes, Dan A; Snyder, Christopher M

    2016-02-01

    Cytomegalovirus (CMV) is a β-herpesvirus that infects most people in the world and is almost always asymptomatic in the healthy host. However, CMV persists for life, requiring continuous immune surveillance to prevent disease and thus, CMV is a frequent complication in immune compromised patients. Many groups have been exploring the potential for adoptive T-cell therapies to control CMV reactivation as well as the progression of solid tumors harboring CMV. In addition, CMV itself is being explored as a vaccine vector for eliciting potent T-cell responses. This review will discuss key features of the basic biology of CMV-specific T cells as well as highlighting unanswered questions and ongoing work in the development of T-cell-based immunotherapies to target CMV.

  10. RESPONSE OF VOLTA CHILDREN TO JET INOCULATION OF COMBINED LIVE MEASLES, SMALLPOX AND YELLOW FEVER VACCINES.

    Science.gov (United States)

    MEYER, H M; HOSTETLER, D D; BERNHEIN, B C; ROGERS, N G; LAMBIN, P; CHASSARY, A; LABUSQUIERE, R; SMADEL, J E

    1964-01-01

    An earlier study established that Upper Volta children respond to vaccination with the Enders live attenuated measles strain in the same general fashion as do children in the USA. The present report describes a second pilot project carried out in Ouagadougou, Upper Volta. During this investigation various mixtures of live measles, smallpox and 17D yellow fever vaccines were introduced into susceptible infants by jet injection. Combining the attenuated virus vaccines did not alter or accentuate the characteristic clinical reactions elicited by the individual components, nor was there evidence of significant immunological interference. From this experience it is concluded that combined vaccination with these agents may be safely and effectively employed in larger programmes as the need dictates.

  11. Novel Cocaine Vaccine Linked to a Disrupted Adenovirus Gene Transfer Vector Blocks Cocaine Psychostimulant and Reinforcing Effects

    Science.gov (United States)

    Wee, Sunmee; Hicks, Martin J; De, Bishnu P; Rosenberg, Jonathan B; Moreno, Amira Y; Kaminsky, Stephen M; Janda, Kim D; Crystal, Ronald G; Koob, George F

    2012-01-01

    Immunotherapy is a promising treatment for drug addiction. However, insufficient immune responses to vaccines in most subjects pose a challenge. In this study, we tested the efficacy of a new cocaine vaccine (dAd5GNE) in antagonizing cocaine addiction-related behaviors in rats. This vaccine used a disrupted serotype 5 adenovirus (Ad) gene transfer vector coupled to a third-generation cocaine hapten, termed GNE (6-(2R,3S)-3-(benzoyloxy)-8-methyl-8-azabicyclo [3.2.1] octane-2-carboxamido-hexanoic acid). Three groups of rats were immunized with dAd5GNE. One group was injected with 3H-cocaine, and radioactivity in the blood and brain was determined. A second group was tested for cocaine-induced locomotor sensitization. A third group was examined for cocaine self-administration, extinction, and reinstatement of responding for cocaine. Antibody titers were determined at various time-points. In each experiment, we added a control group that was immunized with dAd5 without a hapten. The vaccination with dAd5GNE produced long-lasting high titers (>105) of anti-cocaine antibodies in all of the rats. The vaccination inhibited cocaine-induced hyperlocomotor activity and sensitization. Vaccinated rats acquired cocaine self-administration, but they showed less motivation to self-administer cocaine under a progressive-ratio schedule than control rats. When cocaine was not available in a session, control rats exhibited ‘extinction burst' responding, whereas vaccinated rats did not. Moreover, when primed with cocaine, vaccinated rats did not reinstate responding, suggesting a blockade of cocaine-seeking behavior. These data strongly suggest that our dAd5GNE vector-based vaccine may be effective in treating cocaine abuse and addiction. PMID:21918504

  12. Assessment of Lactobacillus gasseri as a Candidate Oral Vaccine Vector

    Science.gov (United States)

    Stoeker, Laura; Nordone, Shila; Gunderson, Sara; Zhang, Lin; Kajikawa, Akinobu; LaVoy, Alora; Miller, Michael; Klaenhammer, Todd R.; Dean, Gregg A.

    2011-01-01

    Lactobacillus species are commensal bacteria that have long been recognized as probiotic microbes and are generally regarded as safe (GRAS) for human consumption. We have investigated the use of L. gasseri as a vaccine vector for oral immunization against mucosal pathogens. Recent research has shown that the immune response to different lactobacilli can vary widely depending on the species or subspecies of Lactobacillus being studied. While some lactobacilli seem to induce oral tolerance, others induce an adaptive immune response. This study characterized the systemic and mucosal immune response to wild-type and genetically modified L. gasseri. L. gasseri primarily activates TLR2/6, with additional activation through the TLR2 homodimer. To expand the Toll-like receptor (TLR) activation profile of L. gasseri and the immunogenicity of the vector, a plasmid containing fliC, the gene encoding bacterial flagellin, was introduced which resulted in the strong activation of TLR5. The treatment of human myeloid dendritic cells with recombinant lactobacilli expressing flagellin triggered phenotypic maturation and the release of proinflammatory cytokines. In contrast, bacterial treatment also resulted in a statistically significant increase in IL-10 production. In vivo studies established that treatment with L. gasseri led to a diversification of B-cell populations in the lamina propria of the murine colon. Furthermore, treatment with genetically modified L. gasseri led to a significant decrease in the percentage of FoxP3+ colonic lymphocytes. Taken together, these data clarify the interaction of L. gasseri with the host immune system and support further investigation of the in vivo immunogenicity of L. gasseri expressing both flagellin and candidate vaccine antigens. PMID:21900526

  13. No evidence of murine leukemia virus-related viruses in live attenuated human vaccines.

    Directory of Open Access Journals (Sweden)

    William M Switzer

    Full Text Available The association of xenotropic murine leukemia virus (MLV-related virus (XMRV in prostate cancer and chronic fatigue syndrome reported in previous studies remains controversial as these results have been questioned by recent data. Nonetheless, concerns have been raised regarding contamination of human vaccines as a possible source of introduction of XMRV and MLV into human populations. To address this possibility, we tested eight live attenuated human vaccines using generic PCR for XMRV and MLV sequences. Viral metagenomics using deep sequencing was also done to identify the possibility of other adventitious agents.All eight live attenuated vaccines, including Japanese encephalitis virus (JEV (SA-14-14-2, varicella (Varivax, measles, mumps, and rubella (MMR-II, measles (Attenuvax, rubella (Meruvax-II, rotavirus (Rotateq and Rotarix, and yellow fever virus were negative for XMRV and highly related MLV sequences. However, residual hamster DNA, but not RNA, containing novel endogenous gammaretrovirus sequences was detected in the JEV vaccine using PCR. Metagenomics analysis did not detect any adventitious viral sequences of public health concern. Intracisternal A particle sequences closest to those present in Syrian hamsters and not mice were also detected in the JEV SA-14-14-2 vaccine. Combined, these results are consistent with the production of the JEV vaccine in Syrian hamster cells.We found no evidence of XMRV and MLV in eight live attenuated human vaccines further supporting the safety of these vaccines. Our findings suggest that vaccines are an unlikely source of XMRV and MLV exposure in humans and are consistent with the mounting evidence on the absence of these viruses in humans.

  14. Conditions Influencing the Efficacy of Vaccination with Live Organisms against Leishmania major Infection

    Science.gov (United States)

    Tabbara, Khaled S.; Peters, Nathan C.; Afrin, Farhat; Mendez, Susana; Bertholet, Sylvie; Belkaid, Yasmine; Sacks, David L.

    2005-01-01

    Numerous experimental vaccines have been developed with the goal of generating long-term cell-mediated immunity to the obligate intracellular parasite Leishmania major, yet inoculation with live, wild-type L. major remains the only successful vaccine in humans. We examined the expression of immunity at the site of secondary, low-dose challenge in the ear dermis to determine the kinetics of parasite clearance and the early events associated with the protection conferred by vaccination with live L. major organisms in C57BL/6 mice. Particular attention was given to the route of vaccination. We observed that the rapidity, strength, and durability of the memory response following subcutaneous vaccination with live parasites in the footpad are even greater than previously appreciated. Antigen-specific gamma interferon (IFN-γ)-producing T cells infiltrate the secondary site by 1.5 weeks, and viable parasites are cleared as early as 2.5 weeks following rechallenge, followed by a rapid drop in IFN-γ+ CD4+ cell numbers in the site. In comparison, intradermal vaccination with live parasites in the ear generates immunity that is delayed in effector cell recruitment to the rechallenge site and in the clearance of parasites from the site. This compromised immunity was associated with a rapid recruitment of interleukin-10 (IL-10)-producing CD4+ T cells to the rechallenge site. Treatment with anti-IL-10-receptor or anti-CD25 antibody enhanced early parasite clearance in ear-vaccinated mice, indicating that chronic infection in the skin generates a population of regulatory cells capable of influencing the level of resistance to reinfection. A delicate balance of effector and regulatory T cells may be required to optimize the potency and durability of vaccines against Leishmaniasis and other intracellular pathogens. PMID:16040984

  15. [Comparative evaluation of neurovirulence of domestic and foreign live mumps vaccine].

    Science.gov (United States)

    Maksimova, O A; Popov, V F; Bektimirov, T A; Grigor'eva, L V; Iunasova, T N; Kaplunova, O P; Sharova, O K

    2001-01-01

    Morphological and immunofluorescent study of changes in the central nervous system of monkeys with mumps was carried out in order to determine the criteria of neurovirulence of different mumps virus strains. Quantitative evaluation showed a lower residual neurovirulence of L-3 strain vs. Jeryl Lynn and Urabe Am9 strains. Use of new methodological approaches to evaluation of mumps vaccine strain neurovirulence will improve the safety control of live mumps vaccines.

  16. [Properties of live antibiotics-resistant anthrax vaccine STI-PR after long-term storage].

    Science.gov (United States)

    Aksenova, L Iu; Buravtseva, N P; Kogotkova, O I; Eremenko, E I; Tsygankova, O I

    2007-01-01

    Study showed that cultural, morphologic, genetic, immunologic characteristics, and resistance to antibiotics of STI-PR anthrax vaccine did not change after storage during 20 years in lyophilized condition. It has been shown that medium for lyophilization plays important role in preservation of vitality of anthrax spores. Optimal preservative properties have been observed for thioureal and sucrose-gelatinous media for lyophilization. Obtained results give reasons for prolongation of shelf live of STI-PR vaccine from 2 - 3 to 5 - 8 years.

  17. Live bacterial delivery systems for development of mucosal vaccines

    NARCIS (Netherlands)

    Thole, J.E.R.; Dalen, P.J. van; Havenith, C.E.G.; Pouwels, P.H.; Seegers, J.F.M.L.; Tielen, F.D.; Zee, M.D. van der; Zegers, N.D.; Shaw, M.

    2000-01-01

    By expression of foreign antigens in attenuated strains derived from bacterial pathogens and in non-pathogenic commensal bacteria, recombinant vaccines are being developed that aim to stimulate mucosal immunity. Recent advances in the pathogenesis and molecular biology of these bacteria have allowed

  18. Coxsackievirus B3 vaccines: use as an expression vector for prevention of myocarditis.

    Science.gov (United States)

    Henke, Andreas; Jarasch, Nadine; Wutzler, Peter

    2008-12-01

    Coxsackievirus B3 (CVB3), a member of the Picornaviridae family, is considered to be one of the most important infectious agents to cause virus-induced myocarditis. Despite improvements in studying virus pathology, structure and molecular biology, as well as the diagnosis of this disease, there is still no virus-specific drug or vaccine in clinical use. During the last 20 years many investigations have been performed to develop classic and modern immunization techniques against CVB3-induced heart disease. One promising approach among others includes the insertion of coding sequences of cytokines into the viral genome. The application of an IFN-gamma-expressing recombinant coxsackievirus vector is especially efficient against CVB3-induced myocarditis. Beside direct IFN-gamma-mediated antiviral effects, the local and simultaneous expression of IFN-gamma by the virus itself activates the immune system in a strong and long-lasting manner, which protects animals completely against subsequent lethal infections independently of the age of the immunized individual and the route of vaccine administration.

  19. Preclinical assessment of viral vectored and protein vaccines targeting the Duffy-binding protein region II of Plasmodium vivax

    Directory of Open Access Journals (Sweden)

    Simone C de Cassan

    2015-07-01

    Full Text Available Malaria vaccine development has largely focused on Plasmodium falciparum; however a reawakening to the importance of P. vivax has spurred efforts to develop vaccines against this difficult to treat and at times severe form of relapsing malaria, which constitutes a significant proportion of human malaria cases worldwide. The almost complete dependence of P. vivax red blood cell invasion on the interaction of the P. vivax Duffy-binding protein region II (PvDBP_RII with the human Duffy antigen receptor for chemokines (DARC, makes this antigen an attractive vaccine candidate against blood-stage P. vivax. Here, we generated both preclinical and clinically-compatible adenoviral and poxviral vectored vaccine candidates expressing the Salvador I allele of PvDBP_RII – including human adenovirus serotype 5 (HAdV5, chimpanzee adenovirus serotype 63 (ChAd63 and modified vaccinia virus Ankara (MVA vectors. We report on the antibody and T cell immunogenicity of these vaccines in mice or rabbits, either used alone in a viral vectored prime-boost regime, or in ‘mixed-modality’ adenovirus prime – protein-in-adjuvant boost regimes (using a recombinant protein PvDBP_RII protein antigen formulated in Montanide®ISA720 or Abisco®100 adjuvants. Antibodies induced by these regimes were found to bind to native parasite antigen from P. vivax infected Thai patients and were capable of inhibiting the binding of PvDBP_RII to its receptor DARC using an in vitro binding inhibition assay. In recent years, recombinant ChAd63 and MVA vectors have been quickly translated into human clinical trials for numerous antigens from P. falciparum as well as a growing number of other pathogens. The vectors reported here are immunogenic in small animals, elicit antibodies against PvDBP_RII and have recently entered clinical trials which will provide the first assessment of the safety and immunogenicity of the PvDBP_RII antigen in humans.

  20. Successful comeback of the single-dose live oral cholera vaccine CVD 103-HgR.

    Science.gov (United States)

    Herzog, Christian

    2016-01-01

    Effective and easy to administer cholera vaccines are in need more than ever, for at risk populations and travellers alike. In many parts of the world cholera is still endemic, causing outbreaks and constituting repeatedly serious public health problems. The oral live cholera vaccine CVD 103-HgR (Orochol, Mutachol), the first genetically modified organism (GMO) used as vaccine, was in its time (launched 1993, Switzerland) the ideal cholera vaccine: single-dose, protective efficacy of 80-100% against moderate to severe cholera, acting within 8 days and exhibiting excellent safety, indiscernible from placebo. However, there were strong headwinds: In the 1990s the indication for cholera vaccines was generally downplayed by experts and in 1997 the European Commission called for a moratorium of GMOs which blocked the registration in the European Union. Thus, demand for this vaccine remained low and in 2003 it was taken off the market for economic reasons. After a decade in obscurity it (Vaxchora) has resurfaced again, now produced in the U.S. and equipped with a U.S. FDA license (June 10, 2016). What had happened? This commentary gives a critical account of an almost unbelievable string of misadventures, emerging adverse circumstances and man-made failures which nearly killed this single-dose live oral cholera vaccine. The good news is that patience and persistence lead to success in the end, allowing good science to prevail for the benefit of those in need. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Co-administration of live measles and yellow fever vaccines and inactivated pentavalent vaccines is associated with increased mortality compared with measles and yellow fever vaccines only. An observational study from Guinea-Bissau

    DEFF Research Database (Denmark)

    Fisker, Ane Bærent; Ravn, Henrik Bylling; Rodrigues, Amabelia

    2014-01-01

    is replacing DTP in many low-income countries and yellow fever vaccine (YF) has been introduced to be given together with MV. Pentavalent and YF vaccines were introduced in Guinea-Bissau in 2008. We investigated whether co-administration of pentavalent vaccine with MV and yellow fever vaccine has similar......Studies from low-income countries indicate that co-administration of inactivated diphtheria-tetanus-pertussis (DTP) vaccine and live attenuated measles vaccine (MV) is associated with increased mortality compared with receiving MV only. Pentavalent (DTP-H. Influenza type B-Hepatitis B) vaccine...

  2. Live Attenuated Influenza Vaccine Enhances Colonization of Streptococcus pneumoniae and Staphylococcus aureus in Mice

    Science.gov (United States)

    Mina, Michael J.; McCullers, Jonathan A.; Klugman, Keith P.

    2014-01-01

    ABSTRACT Community interactions at mucosal surfaces between viruses, like influenza virus, and respiratory bacterial pathogens are important contributors toward pathogenesis of bacterial disease. What has not been considered is the natural extension of these interactions to live attenuated immunizations, and in particular, live attenuated influenza vaccines (LAIVs). Using a mouse-adapted LAIV against influenza A (H3N2) virus carrying the same mutations as the human FluMist vaccine, we find that LAIV vaccination reverses normal bacterial clearance from the nasopharynx and significantly increases bacterial carriage densities of the clinically important bacterial pathogens Streptococcus pneumoniae (serotypes 19F and 7F) and Staphylococcus aureus (strains Newman and Wright) within the upper respiratory tract of mice. Vaccination with LAIV also resulted in 2- to 5-fold increases in mean durations of bacterial carriage. Furthermore, we show that the increases in carriage density and duration were nearly identical in all aspects to changes in bacterial colonizing dynamics following infection with wild-type (WT) influenza virus. Importantly, LAIV, unlike WT influenza viruses, had no effect on severe bacterial disease or mortality within the lower respiratory tract. Our findings are, to the best of our knowledge, the first to demonstrate that vaccination with a live attenuated viral vaccine can directly modulate colonizing dynamics of important and unrelated human bacterial pathogens, and does so in a manner highly analogous to that seen following wild-type virus infection. PMID:24549845

  3. Immune responses to rAAV6: The influence of canine parvovirus vaccination and neonatal administration of viral vector

    Directory of Open Access Journals (Sweden)

    Andrea L H Arnett

    2011-11-01

    Full Text Available Recombinant adeno-associated viral (rAAV vectors promote long-term gene transfer in many animal species. Significant effort has focused on the evaluation of rAAV delivery and the immune response in both murine and canine models of neuromuscular disease. However, canines provided for research purposes are routinely vaccinated against canine parvovirus (CPV. rAAV and CPV possess significant homology and are both parvoviruses. Thus, any immune response generated to CPV vaccination has the potential to cross-react with rAAV vectors. In this study, we investigated the immune response to rAAV6 delivery in a cohort of CPV-vaccinated canines and evaluated multiple vaccination regimens in a mouse model of CPV-vaccination. We show that CPV-vaccination stimulates production of neutralizing antibodies with minimal cross-reactivity to rAAV6. In addition, no significant differences were observed in the magnitude of the rAAV6-directed immune response between CPV-vaccinated animals and controls. Moreover, CPV-vaccination did not inhibit rAAV6-mediated transduction. We also evaluated the immune response to early rAAV6-vaccination in neonatal mice. The influence of maternal hormones and cytokines leads to a relatively permissive state in the neonate. We hypothesized that immaturity of the immune system would permit induction of tolerance to rAAV6 when delivered during the neonatal period. Mice were vaccinated with rAAV6 at 1 or 5 days of age, and subsequently challenged with rAAV6 exposure during adulthood via two sequential IM injections, one month apart. All vaccinated animals generated a significant neutralizing antibody response to rAAV6-vaccination that was enhanced following IM injection in adulthood. Taken together, these data demonstrate that the immune response raised against rAAV6 is distinct from that which is elicited by the standard parvoviral vaccines and is sufficient to prevent stable tolerization in neonatal mice.

  4. Genotyping assay for differentiation of wild-type and vaccine viruses in subjects immunized with live attenuated influenza vaccine.

    Directory of Open Access Journals (Sweden)

    Victoria Matyushenko

    Full Text Available Live attenuated influenza vaccines (LAIVs are considered as safe and effective tool to control influenza in different age groups, especially in young children. An important part of the LAIV safety evaluation is the detection of vaccine virus replication in the nasopharynx of the vaccinees, with special attention to a potential virus transmission to the unvaccinated close contacts. Conducting LAIV clinical trials in some geographical regions with year-round circulation of influenza viruses warrants the development of robust and reliable tools for differentiating vaccine viruses from wild-type influenza viruses in nasal pharyngeal wash (NPW specimens of vaccinated subjects. Here we report the development of genotyping assay for the detection of wild-type and vaccine-type influenza virus genes in NPW specimens of young children immunized with Russian-backbone seasonal trivalent LAIV using Sanger sequencing from newly designed universal primers. The new primer set allowed amplification and sequencing of short fragments of viral genes in NPW specimens and appeared to be more sensitive than conventional real-time RT-PCR protocols routinely used for the detection and typing/subtyping of influenza virus in humans. Furthermore, the new assay is capable of defining the origin of wild-type influenza virus through BLAST search with the generated sequences of viral genes fragments.

  5. [PERSPECTIVES OF DEVELOPMENT OF LIVE RECOMBINANT ANTHRAX VACCINES BASED ON OPPORTUNISTIC AND APATHOGENIC MICROORGANISMS].

    Science.gov (United States)

    Popova, P Yu; Mikshis, N I

    2016-01-01

    Live genetic engineering anthrax vaccines on the platform of avirulent and probiotic micro-organisms are a safe and adequate alternative to preparations based on attenuated Bacillus anthracis strains. Mucosal application results in a direct contact of the vaccine preparations with mucous membranes in those organs arid tissues of the macro-organisms, that are exposed to the pathogen in the first place, resulting in a development of local and systemic immune response. Live recombinant anthrax vaccines could be used both separately as well as in a prime-boost immunization scheme. The review focuses on immunogenic and protective properties of experimental live genetic engineering prearations, created based on members of geni of Salmonella, Lactobacillus and adenoviruses.

  6. Clinical development and regulatory points for consideration for second-generation live attenuated dengue vaccines.

    Science.gov (United States)

    Vannice, Kirsten S; Wilder-Smith, Annelies; Barrett, Alan D T; Carrijo, Kalinka; Cavaleri, Marco; de Silva, Aravinda; Durbin, Anna P; Endy, Tim; Harris, Eva; Innis, Bruce L; Katzelnick, Leah C; Smith, Peter G; Sun, Wellington; Thomas, Stephen J; Hombach, Joachim

    2018-03-07

    Licensing and decisions on public health use of a vaccine rely on a robust clinical development program that permits a risk-benefit assessment of the product in the target population. Studies undertaken early in clinical development, as well as well-designed pivotal trials, allow for this robust characterization. In 2012, WHO published guidelines on the quality, safety and efficacy of live attenuated dengue tetravalent vaccines. Subsequently, efficacy and longer-term follow-up data have become available from two Phase 3 trials of a dengue vaccine, conducted in parallel, and the vaccine was licensed in December 2015. The findings and interpretation of the results from these trials released both before and after licensure have highlighted key complexities for tetravalent dengue vaccines, including concerns vaccination could increase the incidence of dengue disease in certain subpopulations. This report summarizes clinical and regulatory points for consideration that may guide vaccine developers on some aspects of trial design and facilitate regulatory review to enable broader public health recommendations for second-generation dengue vaccines. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Oronasal and intramuscular vaccination of swine with a modified live porcine parvovirus vaccine: multiplication and transmission of the vaccine virus.

    Science.gov (United States)

    Paul, P S; Mengeling, W L

    1984-12-01

    An attenuated strain NADL-2 of porcine parvovirus (PPV) has been used at the 54th cell culture passage as a modified live-virus (MLV) vaccine. The present study was conducted to determine the minimum immunizing dose of MLV, the extent of MLV multiplication in swine tissues, and its transmission from swine administered MLV oronasally or intramuscularly. Immune response to MLV was dose dependent and swine responded to as little as 10(2) median cell-culture infective doses (CCID50). A 10(5) CCID50 of MLV, the largest dose given, induced the best immune response and was used in subsequent experiments. Route of MLV administration also was found to be important. The MLV replicated in tissues of swine after IM inoculation; however, viral antigen in tissues was less, as measured by immunofluorescence, and serum hemagglutination-inhibition titers for PPV were lower in MLV-inoculated swine than we have previously observed in virulent PPV-inoculated swine. In contrast, oronasal inoculation with MLV did not consistently result in infection of pigs; only 5 of 23 swine had virologic and/or serologic evidence of infection. Virus transmission studies indicated that MLV is shed in feces, but shedding occurs later than that in virulent-PPV-inoculated swine and is inconsistent. Delayed transmission of MLV was observed in contact pigs, which were seronegative at 2 weeks, but became seropositive at 4 weeks--indicating that perhaps a virus population capable of infecting pigs by oronasal route was selected by passage through the pig.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Vectors

    DEFF Research Database (Denmark)

    Boeriis, Morten; van Leeuwen, Theo

    2017-01-01

    should be taken into account in discussing ‘reactions’, which Kress and van Leeuwen link only to eyeline vectors. Finally, the question can be raised as to whether actions are always realized by vectors. Drawing on a re-reading of Rudolf Arnheim’s account of vectors, these issues are outlined......This article revisits the concept of vectors, which, in Kress and van Leeuwen’s Reading Images (2006), plays a crucial role in distinguishing between ‘narrative’, action-oriented processes and ‘conceptual’, state-oriented processes. The use of this concept in image analysis has usually focused...

  9. Revaccination with Live Attenuated Vaccines Confer Additional Beneficial Nonspecific Effects on Overall Survival

    DEFF Research Database (Denmark)

    Benn, Christine S; Fisker, Ane B; Whittle, Hilton C

    2016-01-01

    BACKGROUND: Live vaccines against measles (MV), tuberculosis (BCG), polio (OPV) and smallpox reduce mortality more than explained by target-disease prevention. The beneficial nonspecific effects (NSEs) of MV are strongest when MV is given in presence of maternal antibodies. We therefore hypothesi......BACKGROUND: Live vaccines against measles (MV), tuberculosis (BCG), polio (OPV) and smallpox reduce mortality more than explained by target-disease prevention. The beneficial nonspecific effects (NSEs) of MV are strongest when MV is given in presence of maternal antibodies. We therefore...

  10. Live Attenuated Versus Inactivated Influenza Vaccine in Hutterite Children: A Cluster Randomized Blinded Trial.

    Science.gov (United States)

    Loeb, Mark; Russell, Margaret L; Manning, Vanessa; Fonseca, Kevin; Earn, David J D; Horsman, Gregory; Chokani, Khami; Vooght, Mark; Babiuk, Lorne; Schwartz, Lisa; Neupane, Binod; Singh, Pardeep; Walter, Stephen D; Pullenayegum, Eleanor

    2016-11-01

    Whether vaccinating children with intranasal live attenuated influenza vaccine (LAIV) is more effective than inactivated influenza vaccine (IIV) in providing both direct protection in vaccinated persons and herd protection in unvaccinated persons is uncertain. Hutterite colonies, where members live in close-knit, small rural communities in which influenza virus infection regularly occurs, offer an opportunity to address this question. To determine whether vaccinating children and adolescents with LAIV provides better community protection than IIV. A cluster randomized blinded trial conducted between October 2012 and May 2015 over 3 influenza seasons. (ClinicalTrials.gov: NCT01653015). 52 Hutterite colonies in Alberta and Saskatchewan, Canada. 1186 Canadian children and adolescents aged 36 months to 15 years who received the study vaccine and 3425 community members who did not. Children were randomly assigned according to community in a blinded manner to receive standard dosing of either trivalent LAIV or trivalent IIV. The primary outcome was reverse transcriptase polymerase chain reaction-confirmed influenza A or B virus in all participants (vaccinated children and persons who did not receive the study vaccine). Mean vaccine coverage among children in the LAIV group was 76.9% versus 72.3% in the IIV group. Influenza virus infection occurred at a rate of 5.3% (295 of 5560 person-years) in the LAIV group versus 5.2% (304 of 5810 person-years) in the IIV group. The hazard ratio comparing LAIV with IIV for influenza A or B virus was 1.03 (95% CI, 0.85 to 1.24). The study was conducted in Hutterite communities, which may limit generalizability. Immunizing children with LAIV does not provide better community protection against influenza than IIV. The Canadian Institutes for Health Research.

  11. An influenza viral vector Brucella abortus vaccine induces good cross-protection against Brucella melitensis infection in pregnant heifers.

    Science.gov (United States)

    Tabynov, Kaissar; Ryskeldinova, Sholpan; Sansyzbay, Abylai

    2015-07-17

    Brucella melitensis can be transmitted and cause disease in cattle herds as a result of inadequate management of mixed livestock farms. Ideally, vaccines against Brucella abortus for cattle should also provide cross-protection against B. melitensis. Previously we created a novel influenza viral vector B. abortus (Flu-BA) vaccine expressing the Brucella ribosomal proteins L7/L12 or Omp16. This study demonstrated Flu-BA vaccine with adjuvant Montanide Gel01 provided 100% protection against abortion in vaccinated pregnant heifers and good cross-protection of the heifers and their calves or fetuses (90-100%) after challenge with B. melitensis 16M; the level of protection provided by Flu-BA was comparable to the commercial vaccine B. abortus S19. In terms of the index of infection and colonization of Brucella in tissues, both vaccines demonstrated significant (P=0.02 to P<0.0001) protection against B. melitensis 16M infection compared to the negative control group (PBS+Montanide Gel01). Thus, we conclude the Flu-BA vaccine provides cross-protection against B. melitensis infection in pregnant heifers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. [Administration of vaccine against myxomatosis using live MXT by means of external ear puncture with a special needle].

    Science.gov (United States)

    Cupera, Z; Krupka, V; Jiran, E

    1982-01-01

    A new application method was developed and tested for the immunoprophylaxis of rabbits against myxomatosis using a live MXT vaccine. This new application method--injection of the ear with a special double needle--is very simple and easy. Its use enables a five-fold increase in vaccination doses as compared with subcutaneous application while the amount of vaccine remains the same. In laboratory this method with the MXT vaccine secured a 98.2% protection of the vaccinated animals. One vaccination dose contains 18.1 to 37.2 PD50. Eleven months from a single vaccination by injecting the ear, 83% of the rabbits still remained protected against experimental infection. With the use of the new application method of injecting the ear with the special double needle, the live MXT vaccine against myxomatosis in rabbits represents an effective, easily practicable and economically advantageous direction in the immunoprophylaxis of rabbits against myxomatosis.

  13. Inequity in Timeliness of MMR Vaccination in Children Living in the Suburbs of Iranian Cities.

    Science.gov (United States)

    Jadidi, Rahmatollah; Mohammadbeigi, Abolfazl; Mohammadsalehi, Narges; Ansari, Hossein; Ghaderi, Ebrahim

    2015-06-01

    High coverage of immunization is one of the indicators of good performance of health system but timely vaccination is another indicator which is associated with protective effect of vaccines. The present study aimed at evaluating the inequity in timely vaccination with a focus on inequities in timeliness by gender, birth order, parents' education and place of residence (rural or urban). A historical cohort study was conducted on children of 24-47 months of age who were living in the suburbs of big cities in Iran and were selected through stratified proportional sampling method. Only children who had vaccine cards -i.e. 3610 children -were included in data analysis. The primary outcome was age-appropriate vaccination of MMR1. Inequity was measured by Concentration Index (C) and Relative Index of Inequity (RII). Inequity indexes were calculated according to the mother and father's education, child birth order, child's sex and the family's place of residence at the time of vaccination. The overall on-time MMR1 vaccination was 70% and 54.4% for Iranians and Non-Iranians, respectively. The C index of mother and father's education for timely MMR vaccination was 0.023 and was 0.029 in Iranian children as well as 0.044 and 0.019 for non-Iranians, respectively. The C index according to child order in Iranians and Non-Iranians was 0.025 and C=0.078. With regard to children who lived in cities, the on-time vaccination was 0.36% and 0.29% higher than that in rural areas . In male children it was 0.12% and 0.14% higher than that in female children for Iranians and Non-Iranians, respectively. Timeliness MMR vaccination in Iranian children is higher than that in non-Iranian children. Regarding the existence of differences in timely vaccination rate in all Iranian and Non-Iranian children, no evidence was observed for inequity by focusing on parents' education, birth order, gender or place of residence. So, increasing timeliness of vaccination for enhancing the protective effect

  14. Dose response and efficacy of a live, attenuated human rotavirus vaccine in Mexican infants.

    Science.gov (United States)

    Ruiz-Palacios, Guillermo M; Guerrero, M Lourdes; Bautista-Márquez, Aurora; Ortega-Gallegos, Hilda; Tuz-Dzib, Fernando; Reyes-González, Leticia; Rosales-Pedraza, Gustavo; Martínez-López, Julia; Castañón-Acosta, Erika; Cervantes, Yolanda; Costa-Clemens, SueAnn; DeVos, Beatrice

    2007-08-01

    Immunization against rotavirus has been proposed as the most cost-effective intervention to reduce the disease burden associated with this infection worldwide. The objective of this study was to determine the dose response, immunogenicity, and efficacy of 2 doses of an oral, attenuated monovalent G1[P8] human rotavirus vaccine in children from the same setting in Mexico, where the natural protection against rotavirus infection was studied. From June 2001 through May 2003, 405 healthy infants were randomly assigned to 1 of 3 vaccine groups (virus concentrations 10(4.7), 10(5.2), and 10(5.8) infectious units) and to a placebo group and were monitored to the age of 2 years. The vaccine/placebo was administered concurrently with diphtheria-tetanus toxoid-pertussis/hepatitis B/Haemophilus influenzae type b vaccine at 2 and 4 months of age. After the administration of the first vaccine/placebo dose, weekly home visits to collect information regarding infant health were conducted. Stool samples were collected during each gastroenteritis episode and tested for rotavirus antigen and serotype. The vaccine was well tolerated and induced a greater rate of seroconversion than observed in infants who received placebo. For the pooled vaccine groups, efficacy after 2 oral doses was 80% and 95% against any and severe rotavirus gastroenteritis, respectively. Efficacy was 100% against severe rotavirus gastroenteritis and 70% against severe gastroenteritis of any cause with the vaccine at the highest virus concentration (10(5.8) infectious units). The predominant infecting rotavirus serotype in this cohort was wild-type G1 (85%). Adverse events, including fever, irritability, loss of appetite, cough, diarrhea, and vomiting, were similar among vaccinees and placebo recipients. This new oral, live, attenuated human rotavirus vaccine was safe, immunogenic, and highly efficacious in preventing any and, more importantly, severe rotavirus gastroenteritis in healthy infants. This vaccine

  15. Use of the mice passive protection test to evaluate the humoral response in goats vaccinated with Sterne 34F2 live spore vaccine.

    Science.gov (United States)

    Phaswana, P H; Ndumnego, O C; Koehler, S M; Beyer, W; Crafford, J E; van Heerden, H

    2017-09-07

    The Sterne live spore vaccine (34F2) is the most widely used veterinary vaccine against anthrax in animals. Antibody responses to several antigens of Bacillus anthracis have been described with a large focus on those against protective antigen (PA). The focus of this study was to evaluate the protective humoral immune response induced by the live spore anthrax vaccine in goats. Boer goats vaccinated twice (week 0 and week 12) with the Sterne live spore vaccine and naive goats were used to monitor the anti-PA and toxin neutralizing antibodies at week 4 and week 17 (after the second vaccine dose) post vaccination. A/J mice were passively immunized with different dilutions of sera from immune and naive goats and then challenged with spores of B. anthracis strain 34F2 to determine the protective capacity of the goat sera. The goat anti-PA ELISA titres indicated significant sero-conversion at week 17 after the second doses of vaccine (p = 0.009). Mice receiving undiluted sera from goats given two doses of vaccine (twice immunized) showed the highest protection (86%) with only 20% of mice receiving 1:1000 diluted sera surviving lethal challenge. The in vitro toxin neutralization assay (TNA) titres correlated to protection of passively immunized A/J mice against lethal infection with the vaccine strain Sterne 34F2 spores using immune goat sera up to a 1:10 dilution (r s  ≥ 0.522, p = 0.046). This study suggests that the passive mouse protection model could be potentially used to evaluate the protective immune response in livestock animals vaccinated with the current live vaccine and new vaccines.

  16. A single-dose live-attenuated vaccine prevents Zika virus pregnancy transmission and testis damage.

    Science.gov (United States)

    Shan, Chao; Muruato, Antonio E; Jagger, Brett W; Richner, Justin; Nunes, Bruno T D; Medeiros, Daniele B A; Xie, Xuping; Nunes, Jannyce G C; Morabito, Kaitlyn M; Kong, Wing-Pui; Pierson, Theodore C; Barrett, Alan D; Weaver, Scott C; Rossi, Shannan L; Vasconcelos, Pedro F C; Graham, Barney S; Diamond, Michael S; Shi, Pei-Yong

    2017-09-22

    Zika virus infection during pregnancy can cause congenital abnormities or fetal demise. The persistence of Zika virus in the male reproductive system poses a risk of sexual transmission. Here we demonstrate that live-attenuated Zika virus vaccine candidates containing deletions in the 3' untranslated region of the Zika virus genome (ZIKV-3'UTR-LAV) prevent viral transmission during pregnancy and testis damage in mice, as well as infection of nonhuman primates. After a single-dose vaccination, pregnant mice challenged with Zika virus at embryonic day 6 and evaluated at embryonic day 13 show markedly diminished levels of viral RNA in maternal, placental, and fetal tissues. Vaccinated male mice challenged with Zika virus were protected against testis infection, injury, and oligospermia. A single immunization of rhesus macaques elicited a rapid and robust antibody response, conferring complete protection upon challenge. Furthermore, the ZIKV-3'UTR-LAV vaccine candidates have a desirable safety profile. These results suggest that further development of ZIKV-3'UTR-LAV is warranted for humans.Zika virus infection can result in congenital disorders and cause disease in adults, and there is currently no approved vaccine. Here Shan et al. show that a single dose of a live-attenuated Zika vaccine prevents infection, testis damage and transmission to the fetus during pregnancy in different animal models.

  17. A Francisella tularensis live vaccine strain that improves stimulation of antigen-presenting cells does not enhance vaccine efficacy.

    Directory of Open Access Journals (Sweden)

    Deanna M Schmitt

    Full Text Available Vaccination is a proven strategy to mitigate morbidity and mortality of infectious diseases. The methodology of identifying and testing new vaccine candidates could be improved with rational design and in vitro testing prior to animal experimentation. The tularemia vaccine, Francisella tularensis live vaccine strain (LVS, does not elicit complete protection against lethal challenge with a virulent type A Francisella strain. One factor that may contribute to this poor performance is limited stimulation of antigen-presenting cells. In this study, we examined whether the interaction of genetically modified LVS strains with human antigen-presenting cells correlated with effectiveness as tularemia vaccine candidates. Human dendritic cells infected with wild-type LVS secrete low levels of proinflammatory cytokines, fail to upregulate costimulatory molecules, and activate human T cells poorly in vitro. One LVS mutant, strain 13B47, stimulated higher levels of proinflammatory cytokines from dendritic cells and macrophages and increased costimulatory molecule expression on dendritic cells compared to wild type. Additionally, 13B47-infected dendritic cells activated T cells more efficiently than LVS-infected cells. A deletion allele of the same gene in LVS displayed similar in vitro characteristics, but vaccination with this strain did not improve survival after challenge with a virulent Francisella strain. In vivo, this mutant was attenuated for growth and did not stimulate T cell responses in the lung comparable to wild type. Therefore, stimulation of antigen-presenting cells in vitro was improved by genetic modification of LVS, but did not correlate with efficacy against challenge in vivo within this model system.

  18. Stability of live attenuated rotavirus vaccine with selected preservatives and primary containers.

    Science.gov (United States)

    Lal, Manjari; Jarrahian, Courtney; Zhu, Changcheng; Hosken, Nancy A; McClurkan, Chris L; Koelle, David M; Saxon, Eugene; Roehrig, Andrew; Zehrung, Darin; Chen, Dexiang

    2016-05-11

    Rotavirus infection, which can be prevented by vaccination, is responsible for a high burden of acute gastroenteritis disease in children, especially in low-income countries. An appropriate formulation, packaging, and delivery device for oral rotavirus vaccine has the potential to reduce the manufacturing cost of the vaccine and the logistical impact associated with introduction of a new vaccine, simplify the vaccination procedure, and ensure that the vaccine is safely and accurately delivered to children. Single-dose prefilled presentations can be easy to use; however, they are typically more expensive, can be a bottleneck during production, and occupy a greater volume per dose vis-à-vis supply chain storage and medical waste disposal, which is a challenge in low-resource settings. Multi-dose presentations used thus far have other issues, including increased wastage of vaccine and the need for separate delivery devices. In this study, the goals were to evaluate both the technical feasibility of using preservatives to develop a liquid multi-dose formulation and the primary packaging alternatives for orally delivered, liquid rotavirus vaccines. The feasibility evaluation included evaluation of commonly used preservatives for compatibility with rotavirus vaccines and stability testing of rotavirus vaccine in various primary containers, including Lameplast's plastic tubes, BD's oral dispenser version of Uniject™ (Uniject DP), rommelag's blow-fill-seal containers, and MEDInstill's multi-dose vial and pouch. These presentations were compared to a standard glass vial. The results showed that none of the preservatives tested were compatible with a live attenuated rotavirus vaccine because they had a detrimental effect on the viability of the virus. In the presence of preservatives, vaccine virus titers declined to undetectable levels within 1 month. The vaccine formulation without preservatives maintained a stability profile over 12 months in all primary containers

  19. Comparative study on three locally developed live orf virus vaccines for sheep in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Fahdel M. Housawi

    2012-02-01

    Full Text Available The epidemiology of orf virus infection in Saudi Arabia (SA has been researched since 1990. The results obtained during this period indicate that the disease is widespread, has great economic impact and that no vaccine has been used against it. The present study compares the immunogenicity and protective efficacy of three locally developed live orf virus vaccines. Two of them differ in their passage history in Vero cell culture and the third was used as a virulent virus in glycerine buffer. To the best of the authors’ knowledge, no similar comparative study has been conducted in the Middle East utilising three types of vaccines prepared from the same virus strain. Selection of the candidate seed orf virus and performance of the quality control tests were as laid out by the OIE for veterinary vaccine production. The vaccine seed virus was a field orf virus isolated from a previous orf outbreak in Saudi Arabia. A simple novel formula was developed to calculate the rate of reduction in the healing time (RHT % in the challenged sheep. This allowed direct comparison of the efficacy of the three types of vaccines employed in the present study. The efficacy of each vaccine was tested on a cohort of local Noemi sheep.

  20. Safety and immunogenicity of a live attenuated Japanese encephalitis chimeric virus vaccine (IMOJEV®) in children.

    Science.gov (United States)

    Chokephaibulkit, K; Houillon, G; Feroldi, E; Bouckenooghe, A

    2016-01-01

    JE-CV (IMOJEV®, Sanofi Pasteur, France) is a live attenuated virus vaccine constructed by inserting coding sequences of the prM and E structural proteins of the Japanese encephalitis SA14-14-2 virus into the genome of yellow fever 17D virus. Primary immunization with JE-CV requires a single dose of the vaccine. This article reviews clinical trials of JE-CV in children aged up to 6 years conducted in countries across South-East Asia. Strong and persistent antibody responses were observed after single primary and booster doses, with 97% of children seroprotected up to five years after booster vaccination. Models of long-term antibody persistence predict a median duration of protection of approximately 30 years after a booster dose. The safety and reactogenicity profiles of JE-CV primary and booster doses are comparable to other widely used childhood vaccines.

  1. Cell-mediated and humoral immune responses induced by scarification vaccination of human volunteers with a new lot of the live vaccine strain of Francisella tularensis.

    Science.gov (United States)

    Waag, D M; Galloway, A; Sandstrom, G; Bolt, C R; England, M J; Nelson, G O; Williams, J C

    1992-01-01

    Tularemia is a disease caused by the facultative intracellular bacterium Francisella tularensis. We evaluated a new lot of live F. tularensis vaccine for its immunogenicity in human volunteers. Scarification vaccination induced humoral and cell-mediated immune responses. Indications of a positive immune response after vaccination included an increase in specific antibody levels, which were measured by enzyme-linked immunosorbent and immunoblot assays, and the ability of peripheral blood lymphocytes to respond to whole F. tularensis bacteria as recall antigens. Vaccination caused a significant rise (P less than 0.05) in immunoglobulin A (IgA), IgG, and IgM titers. Lymphocyte stimulation indices were significantly increased (P less than 0.01) in vaccinees 14 days after vaccination. These data verify that this new lot of live F. tularensis vaccine is immunogenic. Images PMID:1400988

  2. Immunogenicity and protective efficacy of a live attenuated H5N1 vaccine in nonhuman primates.

    Directory of Open Access Journals (Sweden)

    Shufang Fan

    2009-05-01

    Full Text Available The continued spread of highly pathogenic H5N1 influenza viruses among poultry and wild birds, together with the emergence of drug-resistant variants and the possibility of human-to-human transmission, has spurred attempts to develop an effective vaccine. Inactivated subvirion or whole-virion H5N1 vaccines have shown promising immunogenicity in clinical trials, but their ability to elicit protective immunity in unprimed human populations remains unknown. A cold-adapted, live attenuated vaccine with the hemagglutinin (HA and neuraminidase (NA genes of an H5N1 virus A/VN/1203/2004 (clade 1 was protective against the pulmonary replication of homologous and heterologous wild-type H5N1 viruses in mice and ferrets. In this study, we used reverse genetics to produce a cold-adapted, live attenuated H5N1 vaccine (AH/AAca that contains HA and NA genes from a recent H5N1 isolate, A/Anhui/2/05 virus (AH/05 (clade 2.3, and the backbone of the cold-adapted influenza H2N2 A/AnnArbor/6/60 virus (AAca. AH/AAca was attenuated in chickens, mice, and monkeys, and it induced robust neutralizing antibody responses as well as HA-specific CD4+ T cell immune responses in rhesus macaques immunized twice intranasally. Importantly, the vaccinated macaques were fully protected from challenge with either the homologous AH/05 virus or a heterologous H5N1 virus, A/bar-headed goose/Qinghai/3/05 (BHG/05; clade 2.2. These results demonstrate for the first time that a cold-adapted H5N1 vaccine can elicit protective immunity against highly pathogenic H5N1 virus infection in a nonhuman primate model and provide a compelling argument for further testing of double immunization with live attenuated H5N1 vaccines in human trials.

  3. Non-specific Effect of Vaccines: Immediate Protection against Respiratory Syncytial Virus Infection by a Live Attenuated Influenza Vaccine

    Directory of Open Access Journals (Sweden)

    Young J. Lee

    2018-01-01

    Full Text Available The non-specific effects (NSEs of vaccines have been discussed for their potential long-term beneficial effects beyond direct protection against a specific pathogen. Cold-adapted, live attenuated influenza vaccine (CAIV induces local innate immune responses that provide a broad range of antiviral immunity. Herein, we examined whether X-31ca, a donor virus for CAIVs, provides non-specific cross-protection against respiratory syncytial virus (RSV. The degree of RSV replication was significantly reduced when X-31ca was administered before RSV infection without any RSV-specific antibody responses. The vaccination induced an immediate release of cytokines and infiltration of leukocytes into the respiratory tract, moderating the immune perturbation caused by RSV infection. The potency of protection against RSV challenge was significantly reduced in TLR3-/- TLR7-/- mice, confirming that the TLR3/7 signaling pathways are necessary for the observed immediate and short-term protection. The results suggest that CAIVs provide short-term, non-specific protection against genetically unrelated respiratory pathogens. The additional benefits of CAIVs in mitigating acute respiratory infections for which vaccines are not yet available need to be assessed in future studies.

  4. Comparison of immune persistence among inactivated and live attenuated hepatitis a vaccines 2 years after a single dose

    Science.gov (United States)

    Zhang, Xiaoshu; An, Jing; Tu, Aixia; Liang, Xuefeng; Cui, Fuqiang; Zheng, Hui; Tang, Yu; Liu, Jianfeng; Wang, Xuxia; Zhang, Ningjing; Li, Hui

    2016-01-01

    ABSTRACT Objective: Compare immune persistence from one dose of each of 3 different hepatitis A vaccines when given to school-age children: a domestic, live attenuated hepatitis A vaccine (H2 vaccine); a domestic inactivated hepatitis A vaccine (Healive®); and an imported, inactivated hepatitis A vaccine (Havrix®),.Methods: School-age children were randomized into 1 of 4 groups to receive a single dose of a vaccine: H2 vaccine, Healive®, Havrix®, or hepatitis B vaccine [control]. Serum samples were collected 12 and 24 months after vaccination for measurement of anti-HAV IgG using microparticle enzyme immunoassay. Seropositivity was defined as ≥ 20 mUI/ml. We compared groups on seropositivity and geometric mean concentration (GMC). Results: Seropositive rates for the H2, Healive®, Havrix®, and control groups were 64%, 94.4%, 73%, and 1.0%, respectively, 12-months post-vaccination; and 63%, 95.6%, 72%, and 1.0%, respectively 24-months post-vaccination. Seropositivity was greater for Healive® than for H2 and Havrix® at 12 months (p-values a single dose of inactivated hepatitis A vaccine and live attenuated hepatitis A vaccine. PMID:27494260

  5. Generation and characterization of a novel candidate gene therapy and vaccination vector based on human species D adenovirus type 56.

    Science.gov (United States)

    Duffy, Margaret R; Alonso-Padilla, Julio; John, Lijo; Chandra, Naresh; Khan, Selina; Ballmann, Monika Z; Lipiec, Agnieszka; Heemskerk, Evert; Custers, Jerome; Arnberg, Niklas; Havenga, Menzo; Baker, Andrew H; Lemckert, Angelique

    2018-01-01

    The vectorization of rare human adenovirus (HAdV) types will widen our knowledge of this family and their interaction with cells, tissues and organs. In this study we focus on HAdV-56, a member of human Ad species D, and create ease-of-use cloning systems to generate recombinant HAdV-56 vectors carrying foreign genes. We present in vitro transduction profiles for HAdV-56 in direct comparison to the most commonly used HAdV-5-based vector. In vivo characterizations demonstrate that when it is delivered intravenously (i.v.) HAdV-56 mainly targets the spleen and, to a lesser extent, the lungs, whilst largely bypassing liver transduction in mice. HAdV-56 triggered robust inflammatory and cellular immune responses, with higher induction of IFNγ, TNFα, IL5, IL6, IP10, MCP1 and MIG1 compared to HAdV-5 following i.v. administration. We also investigated its potential as a vaccine vector candidate by performing prime immunizations in mice with HAdV-56 encoding luciferase (HAdV-56-Luc). Direct comparisons were made to HAdV-26, a highly potent human vaccine vector currently in phase II clinical trials. HAdV-56-Luc induced luciferase 'antigen'-specific IFNγ-producing cells and anti-HAdV-56 neutralizing antibodies in Balb/c mice, demonstrating a near identical profile to that of HAdV-26. Taken together, the data presented provides further insight into human Ad receptor/co-receptor usage, and the first report on HAdV-56 vectors and their potential for gene therapy and vaccine applications.

  6. Yellow fever 17D-vectored vaccines expressing Lassa virus GP1 and GP2 glycoproteins provide protection against fatal disease in guinea pigs.

    Science.gov (United States)

    Jiang, Xiaohong; Dalebout, Tim J; Bredenbeek, Peter J; Carrion, Ricardo; Brasky, Kathleen; Patterson, Jean; Goicochea, Marco; Bryant, Joseph; Salvato, Maria S; Lukashevich, Igor S

    2011-02-01

    Yellow Fever (YF) and Lassa Fever (LF) are two prevalent hemorrhagic fevers co-circulating in West Africa and responsible for thousands of deaths annually. The YF vaccine 17D has been used as a vector for the Lassa virus glycoprotein precursor (LASV-GPC) or their subunits, GP1 (attachment glycoprotein) and GP2 (fusion glycoprotein). Cloning shorter inserts, LASV-GP1 and -GP2, between YF17D E and NS1 genes enhanced genetic stability of recombinant viruses, YF17D/LASV-GP1 and -GP2, in comparison with YF17D/LASV-GPC recombinant. The recombinant viruses were replication competent and properly processed YF proteins and LASV GP antigens in infected cells. YF17D/LASV-GP1 and -GP2 induced specific CD8+ T cell responses in mice and protected strain 13 guinea pigs against fatal LF. Unlike immunization with live attenuated reassortant vaccine ML29, immunization with YF17D/LASV-GP1 and -GP2 did not provide sterilizing immunity. This study demonstrates the feasibility of YF17D-based vaccine to control LF in West Africa. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Yellow fever 17D-vectored vaccines expressing Lassa virus GP1 and GP2 glycoproteins provide protection against fatal disease in guinea pigs

    Science.gov (United States)

    Jiang, Xiaohong; Dalebout, Tim J.; Bredenbeek, Peter J.; Carrion, Ricardo; Brasky, Kathleen; Patterson, Jean; Goicochea, Marco; Bryant, Joseph; Salvato, Maria S.; Lukashevich, Igor S.

    2010-01-01

    Yellow Fever (YF) and Lassa Fever (LF) are two prevalent hemorrhagic fevers co-circulating in West Africa and responsible for thousands of deaths annually. The YF vaccine 17D has been used as a vector for the Lassa virus glycoprotein precursor (LASV-GPC) or their subunits, GP1 (attachment glycoprotein) and GP2 (fusion glycoprotein). Cloning shorter inserts, LASV GP1 and GP2, between YF17D E and NS1 genes enhanced genetic stability of recombinant viruses, YF17D/LASV-GP1 and –GP2, in comparison with YF17D/LASV-GPC recombinant. The recombinant viruses were replication competent and properly processed YF and LASV GP proteins in infected cells. YF17D/LASV-GP1&GP2 induced specific CD8+ T cell responses in mice and protected strain 13 guinea pigs against fatal LF. Unlike immunization with live attenuated reassortant vaccine ML29, immunization with YF17D/LASV-GP1&GP2 did not provide sterilizing immunity. This study demonstrates the feasibility of YF17D-based vaccine to control LF in West Africa. PMID:21145373

  8. Vaccination of children with a live-attenuated, intranasal influenza vaccine – analysis and evaluation through a Health Technology Assessment

    Directory of Open Access Journals (Sweden)

    Andersohn, Frank

    2014-10-01

    Full Text Available [english] Background: Influenza is a worldwide prevalent infectious disease of the respiratory tract annually causing high morbidity and mortality in Germany. Influenza is preventable by vaccination and this vaccination is so far recommended by the (STIKO as a standard vaccination for people from the age of 60 onwards. Up to date a parenterally administered trivalent inactivated vaccine (TIV has been in use almost exclusively. Since 2011 however a live-attenuated vaccine (LAIV has been approved additionally. Consecutively, since 2013 the STIKO recommends LAIV (besides TIV for children from 2 to 17 years of age, within the scope of vaccination by specified indications. LAIV should be preferred administered in children from 2 to 6 of age. The objective of this Health Technology Assessment (HTA is to address various research issues regarding the vaccination of children with LAIV. The analysis was performed from a medical, epidemiological and health economic perspective, as well as from an ethical, social and legal point of view.Method: An extensive systematic database research was performed to obtain relevant information. In addition a supplementary research by hand was done. Identified literature was screened in two passes by two independent reviewers using predefined inclusion and exclusion criteria. Included literature was evaluated in full-text using acknowledged standards. Studies were graded with the highest level of evidence (1++, if they met the criteria of Results: For the medical section, the age of the study participants ranges from 6 months to 17 years. Regarding study efficacy, in children aged 6 months to ≤7 years, LAIV is superior to placebo as well as to a vac-cination with TIV (Relative Risk Reduction – RRR – of laboratory confirmed influenza infection approx. 80% and 50%, respectively. In children aged >7 to 17 years (= 18th year of their lives, LAIV is superior to a vaccination with TIV (RRR 32%. For this age group, no

  9. Envelope exchange for the generation of live-attenuated arenavirus vaccines.

    Directory of Open Access Journals (Sweden)

    Andreas Bergthaler

    2006-06-01

    Full Text Available Arenaviruses such as Lassa fever virus cause significant mortality in endemic areas and represent potential bioterrorist weapons. The occurrence of arenaviral hemorrhagic fevers is largely confined to Third World countries with a limited medical infrastructure, and therefore live-attenuated vaccines have long been sought as a method of choice for prevention. Yet their rational design and engineering have been thwarted by technical limitations. In addition, viral genes had not been identified that are needed to cause disease but can be deleted or substituted to generate live-attenuated vaccine strains. Lymphocytic choriomeningitis virus, the prototype arenavirus, induces cell-mediated immunity against Lassa fever virus, but its safety for humans is unclear and untested. Using this virus model, we have developed the necessary methodology to efficiently modify arenavirus genomes and have exploited these techniques to identify an arenaviral Achilles' heel suitable for targeting in vaccine design. Reverse genetic exchange of the viral glycoprotein for foreign glycoproteins created attenuated vaccine strains that remained viable although unable to cause disease in infected mice. This phenotype remained stable even after extensive propagation in immunodeficient hosts. Nevertheless, the engineered viruses induced T cell-mediated immunity protecting against overwhelming systemic infection and severe liver disease upon wild-type virus challenge. Protection was established within 3 to 7 d after immunization and lasted for approximately 300 d. The identification of an arenaviral Achilles' heel demonstrates that the reverse genetic engineering of live-attenuated arenavirus vaccines is feasible. Moreover, our findings offer lymphocytic choriomeningitis virus or other arenaviruses expressing foreign glycoproteins as promising live-attenuated arenavirus vaccine candidates.

  10. Envelope Exchange for the Generation of Live-Attenuated Arenavirus Vaccines.

    Directory of Open Access Journals (Sweden)

    2006-06-01

    Full Text Available Arenaviruses such as Lassa fever virus cause significant mortality in endemic areas and represent potential bioterrorist weapons. The occurrence of arenaviral hemorrhagic fevers is largely confined to Third World countries with a limited medical infrastructure, and therefore live-attenuated vaccines have long been sought as a method of choice for prevention. Yet their rational design and engineering have been thwarted by technical limitations. In addition, viral genes had not been identified that are needed to cause disease but can be deleted or substituted to generate live-attenuated vaccine strains. Lymphocytic choriomeningitis virus, the prototype arenavirus, induces cell-mediated immunity against Lassa fever virus, but its safety for humans is unclear and untested. Using this virus model, we have developed the necessary methodology to efficiently modify arenavirus genomes and have exploited these techniques to identify an arenaviral Achilles' heel suitable for targeting in vaccine design. Reverse genetic exchange of the viral glycoprotein for foreign glycoproteins created attenuated vaccine strains that remained viable although unable to cause disease in infected mice. This phenotype remained stable even after extensive propagation in immunodeficient hosts. Nevertheless, the engineered viruses induced T cell-mediated immunity protecting against overwhelming systemic infection and severe liver disease upon wild-type virus challenge. Protection was established within 3 to 7 d after immunization and lasted for approximately 300 d. The identification of an arenaviral Achilles' heel demonstrates that the reverse genetic engineering of live-attenuated arenavirus vaccines is feasible. Moreover, our findings offer lymphocytic choriomeningitis virus or other arenaviruses expressing foreign glycoproteins as promising live-attenuated arenavirus vaccine candidates.

  11. Use of modified live feline panleukopenia virus vaccine to immunize dogs against canine parvovirus.

    Science.gov (United States)

    Pollock, R V; Carmichael, L E

    1983-02-01

    Modified live feline panleukopenia virus (FPLV) vaccine protected dogs against canine parvovirus (CPV) infection. However, unlike the long-lived (greater than or equal to 20-month) immunity engendered by CPV infection, the response of dogs to living FPLV was variable. Doses of FPLV (snow leopard strain) in excess of 10(5.7) TCID50 were necessary for uniform immunization; smaller inocula resulted in decreased success rates. The duration of immunity, as measured by the persistence of hemagglutination-inhibiting antibody, was related to the magnitude of the initial response to vaccination; dogs with vigorous initial responses resisted oronasal CPV challenge exposure 6 months after vaccination, and hemagglutination-inhibiting antibodies persisted in such dogs for greater than 1 year. Limited replication of FPLV in dogs was demonstrated, but unlike CPV, the feline virus did not spread to contact dogs or cats. Adverse reactions were not associated with living FPLV vaccination, and FPLV did not interfere with simultaneous response to attenuated canine distemper virus.

  12. Development of live attenuated sparfloxacin-resistant Streptococcus agalactiae polyvalent vaccines to protect Nile tilapia

    Science.gov (United States)

    To develop attenuated bacteria as potential live vaccines, sparfloxacin was used in this study to modify 40 isolates of Streptococcus agalactiae. Majority of S. agalactiae used in this study were able to develop at least 80-fold resistance to sparfloxacin. When the virulence of the sparfloxacin-resi...

  13. Architectural Insight into Inovirus-Associated Vectors (IAVs and Development of IAV-Based Vaccines Inducing Humoral and Cellular Responses: Implications in HIV-1 Vaccines

    Directory of Open Access Journals (Sweden)

    Kyriakos A. Hassapis

    2014-12-01

    Full Text Available Inovirus-associated vectors (IAVs are engineered, non-lytic, filamentous bacteriophages that are assembled primarily from thousands of copies of the major coat protein gp8 and just five copies of each of the four minor coat proteins gp3, gp6, gp7 and gp9. Inovirus display studies have shown that the architecture of inoviruses makes all coat proteins of the inoviral particle accessible to the outside. This particular feature of IAVs allows foreign antigenic peptides to be displayed on the outer surface of the virion fused to its coat proteins and for more than two decades has been exploited in many applications including antibody or peptide display libraries, drug design, and vaccine development against infectious and non-infectious diseases. As vaccine carriers, IAVs have been shown to elicit both a cellular and humoral response against various pathogens through the display of antibody epitopes on their coat proteins. Despite their high immunogenicity, the goal of developing an effective vaccine against HIV-1 has not yet materialized. One possible limitation of previous efforts was the use of broadly neutralizing antibodies, which exhibited autoreactivity properties. In the past five years, however, new, more potent broadly neutralizing antibodies that do not exhibit autoreactivity properties have been isolated from HIV-1 infected individuals, suggesting that vaccination strategies aimed at producing such broadly neutralizing antibodies may confer protection against infection. The utilization of these new, broadly neutralizing antibodies in combination with the architectural traits of IAVs have driven the current developments in the design of an inovirus-based vaccine against HIV-1. This article reviews the applications of IAVs in vaccine development, with particular emphasis on the design of inoviral-based vaccines against HIV-1.

  14. Strategies to obtain multiple recombinant modified vaccinia Ankara vectors. Applications to influenza vaccines.

    Science.gov (United States)

    Barbieri, Andrea; Panigada, Maddalena; Soprana, Elisa; Di Mario, Giuseppina; Gubinelli, Francesco; Bernasconi, Valentina; Recagni, Marta; Donatelli, Isabella; Castrucci, Maria R; Siccardi, Antonio G

    2018-01-01

    As a vaccination vector, MVA has been widely investigated both in animal models and humans. The construction of recombinant MVA (rMVA) relies on homologous recombination between an acceptor virus and a donor plasmid in infected/transfected permissive cells. Our construction strategy "Red-to-Green gene swapping" - based on the exchange of two fluorescent markers within the flanking regions of MVA deletion ΔIII, coupled to fluorescence activated cell sorting - is here extended to a second insertion site, within the flanking regions of MVA deletion ΔVI. Exploiting this strategy, both double and triple rMVA were constructed, expressing as transgenes the influenza A proteins HA, NP, M1, and PB1. Upon validation of the harbored transgenes co-expression, double and triple recombinants rMVA(ΔIII)-NP-P2A-M1 and rMVA(ΔIII)-NP-P2A-M1-(ΔVI)-PB1 were assayed for in vivo immunogenicity and protection against lethal challenge. In vivo responses were identical to those obtained with the reported combinations of single recombinants, supporting the feasibility and reliability of the present improvement and the extension of Red-to-Green gene swapping to insertion sites other than ΔIII. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Microneedle-mediated immunization of an adenovirus-based malaria vaccine enhances antigen-specific antibody immunity and reduces anti-vector responses compared to the intradermal route

    OpenAIRE

    Carey, John B.; Vrdoljak, Anto; O'Mahony, Conor; Hill, Adrian V. S.; Draper, Simon J.; Moore, Anne C.

    2014-01-01

    Substantial effort has been placed in developing efficacious recombinant attenuated adenovirus-based vaccines. However induction of immunity to the vector is a significant obstacle to its repeated use. Here we demonstrate that skin-based delivery of an adenovirus-based malaria vaccine, HAdV5-PyMSP142, to mice using silicon microneedles induces equivalent or enhanced antibody responses to the encoded antigen, however it results in decreased anti-vector responses, compared to intradermal delive...

  16. T Helper 17 Promotes Induction of Antigen-Specific Gut-Mucosal Cytotoxic T Lymphocytes following Adenovirus Vector Vaccination

    Directory of Open Access Journals (Sweden)

    Masahisa Hemmi

    2017-11-01

    Full Text Available Few current vaccines can establish antigen (Ag-specific immune responses in both mucosal and systemic compartments. Therefore, development of vaccines providing defense against diverse infectious agents in both compartments is of high priority in global health. Intramuscular vaccination of an adenovirus vector (Adv has been shown to induce Ag-specific cytotoxic T lymphocytes (CTLs in both systemic and gut-mucosal compartments. We previously found that type I interferon (IFN signaling is required for induction of gut-mucosal, but not systemic, CTLs following vaccination; however, the molecular mechanism involving type I IFN signaling remains unknown. Here, we found that T helper 17 (Th17-polarizing cytokine expression was down-regulated in the inguinal lymph nodes (iLNs of Ifnar2−/− mice, resulting in the reduction of Ag-specific Th17 cells in the iLNs and gut mucosa of the mice. We also found that prior transfer of Th17 cells reversed the decrease in the number of Ag-specific gut-mucosal CTLs in Ifnar2−/− mice following Adv vaccination. Additionally, prior transfer of Th17 cells into wild-type mice enhanced the induction of Ag-specific CTLs in the gut mucosa, but not in systemic compartments, suggesting a gut mucosa-specific mechanism where Th17 cells regulate the magnitude of vaccine-elicited Ag-specific CTL responses. These data suggest that Th17 cells translate systemic type I IFN signaling into a gut-mucosal CTL response following vaccination, which could promote the development of promising Adv vaccines capable of establishing both systemic and gut-mucosal protective immunity.

  17. Closing the manufacturing process of dendritic cell vaccines transduced with adenovirus vectors.

    Science.gov (United States)

    Gulen, Dumrul; Abe, Fuminori; Maas, Sarah; Reed, Elizabeth; Cowan, Kenneth; Pirruccello, Samuel; Wisecarver, James; Warkentin, Phyllis; Northam, Matt; Turken, Orhan; Coskun, Ugur; Senesac, Joe; Talmadge, James E

    2008-12-20

    Anticancer immunotherapy using dendritic cell (DC) based vaccines provides an adjuvant therapeutic strategy that is not cross reactive with conventional therapeutics. However, manufacturing of DC vaccines requires stringent adherence to Good Manufacturing Practice (GMP) methods and rigorous standardization. Optimally this includes a closed system for monocyte isolation, in combination with closed culture and washing systems and an effective vector transduction strategy. In this study, we used the Gambro Elutra to enrich monocytes from non-mobilized leukapheresis products collected from healthy donors. This approach enriched monocytes from an average frequency of 13.6+3.2% (mean+SEM), to an average frequency of 79.5+4.3% following enrichment with a yield of 79 to 100%. The monocytes were then cultured in a closed system using gas permeable Vuelife fluoroethylene propylene (FEP) bags and X-vivo-15 media containing 10 ng/ml granulocyte-macrophage colony-stimulation factor (GM-CSF) and 5 ng/ml Interleukin (IL) 4. The cultures were re-fed on days two and four, with a 25% media volume and cytokines. Following culture for seven days, the cells were harvested using a Cobe-2991 and concentrated using a bench centrifuge retrofitted with blocks to allow centrifugation of 72 ml bags and supernatant removed using a plasma extractor. This approach reduced the media volume to an average of 17.4 ml and an average DC concentration of 6.3+1.0x10(7) cells/ml, a viability of 93.8+2.2%, a purity of 88.9+3.3% and a total yield of 8.5+1.4x10(8) DCs. Based on the identification of DR+ cells as DCs we had an average yield of 46+8% using a calculation based on the number of monocytes in the apheresis product and the resulting DCs differentiated from monocytes. The use of DCs as a vaccine, required transduction with an adenovirus (Adv) vector with the tumor suppressor, p53 transgene (Adv5CMV-p53) as the antigen at a DC concentration of 9x10(6) DCs/ml at an Ad5CMV-p53: DC ratio of 20

  18. [Effect of immune modulation on immunogenic and protective activity of a live plague vaccine].

    Science.gov (United States)

    Karal'nik, B V; Ponomareva, T S; Deriabin, P N; Denisova, T G; Mel'nikova, N N; Tugambaev, T I; Atshabar, B B; Zakarian, S B

    2014-01-01

    Comparative evaluation of the effect of polyoxidonium and betaleukin on immunogenic and protective activity of a live plague vaccine in model animal experiments. Plague vaccine EV, polyoxidonium, betaleukin, erythrocytic antigenic diagnosticum for determination of F1 antibodies and immune reagents for detection of lymphocytes with F1 receptors (LFR) in adhesive test developed by the authors were used. The experiments were carried out in 12 rabbits and 169 guinea pigs. Immune modulation accelerated the appearance and disappearance of LFR (early phase) and ensured a more rapid and intensive antibody formation (effector phase). Activation by betaleukin is more pronounced than by polyoxidonium. The more rapid and intensive was the development of early phase, the more effective was antibody response to the vaccine. Immune modulation in the experiment with guinea pigs significantly increased protective activity of the vaccine. The use of immune modulators increased immunogenic (in both early and effector phases of antigen-specific response) and protective activity of the EV vaccine. A connection between the acceleration of the first phase of antigen-specific response and general intensity of effector phase of immune response to the EV vaccine was detected. ,

  19. [Evaluation of immunogenicity and safety of 2 immunizations with allantoic intranasal live influenza vaccine Ultragrivac].

    Science.gov (United States)

    Shishkina, L N; Mazurkova, N A; Ternovoĭ, V A; Bulychev, L E; Tumanov, Iu V; Skarnovich, M O; Kabanov, A S; Ryndiuk, N N; Kuzubov, V I; Mironov, A N; Stavskiĭ, E A; Drozdov, I G

    2011-01-01

    Evaluate reactogenicity, safety and immunogenicity in phase 2 clinical trials of 2 immunization schedules with Ultragrivac--an allantoic intranasal life influenza vaccine based on A/17/ duck/Potsdam/86/92 [17/H5] reassortant strain. 4 groups of volunteers participated in the study: group 1--40 individuals were vaccinated twice with a 10 day interval; group 2--40 individuals were vaccinated twice with a 21 day interval; group 3 (control)--10 individuals received placebo twice with a 10 day interval; group 4 (control)--10 individuals received placebo twice with a 21 day interval. Local (secretory IgA), cellular and humoral immune response were evaluated. Humoral immunity was evaluated by the intensity of increase of geometric mean antibody titers against 2 influenza virus strains A/17/duck/Potsdam/86/92 [17/H5] and A/chicken/Suzdalka/Nov-1 1/2005 (H5N1), and by the level of significant (4 times or more) antibody seroconversions after the vaccination. After the use of Ultragrivac the level of secretory IgA in the nasal cavity of vaccinated volunteers in the groups with revaccination intervals of 10 and 21 days increased significantly. The second immunization with 10 or 21 day intervals significantly increased postvaccinal humoral immune response. Humoral immune response induction after 2 vaccinations with 10 day interval was no less effective than with 21 day interval. Ultragrivac allantoic intranasal live influenza vaccine is areactogenic, harmless for vaccinated individuals, safe for those around, and has immunogenic properties against not only homologous virus A(H5N2), but also against influenza strain A(H5N1).

  20. Different levels of immunogenicity of two strains of Fowlpox virus as recombinant vaccine vectors eliciting T-cell responses in heterologous prime-boost vaccination strategies.

    Science.gov (United States)

    Cottingham, Matthew G; van Maurik, Andre; Zago, Manola; Newton, Angela T; Anderson, Richard J; Howard, M Keith; Schneider, Jörg; Skinner, Michael A

    2006-07-01

    The FP9 strain of F has been described as a more immunogenic recombinant vaccine vector than the Webster FPV-M (FPW) strain (R. J. Anderson et al., J. Immunol. 172:3094-3100, 2004). This study expands the comparison to include two separate recombinant antigens and multiple, rather than single, independent viral clones derived from the two strains. Dual-poxvirus heterologous prime-boost vaccination regimens using individual clones of recombinant FP9 or FPW in combination with recombinant modified V Ankara expressing the same antigen were evaluated for their ability to elicit T-cell responses against recombinant antigens from Plasmodium berghei (circumsporozoite protein) or human immunodeficiency virus type 1 (a Gag-Pol-Nef fusion protein). Gamma interferon enzyme-linked immunospot assay and fluorescence-activated cell sorting assays of the responses to specific epitopes confirmed the approximately twofold-greater cellular immunogenicity of FP9 compared to FPW, when given as the priming or boosting immunization. Equality of transgene expression in mouse cells infected with the two strains in vitro was verified by Western blotting. Directed partial sequence analysis and PCR analysis of FPW and comparison to available whole-genome sequences revealed that many loci that are mutated in the highly attenuated and culture-adapted FP9 strain are wild type in FPW, including the seven multikilobase deletions. These "passage-specific" alterations are hypothesized to be involved in determining the immunogenicity of fowlpox virus as a recombinant vaccine vector.

  1. Transcutaneous delivery of T Cell-inducing viral vector Malaria vaccines by microneedle patches

    OpenAIRE

    2011-01-01

    There is an urgent need for improvements to existing vaccine delivery technologies to run parallel with the development of new-generation vaccines. The burdens of needle-based immunisation strategies are exacerbated by poor resource provision in such areas as sub-Saharan Africa, where annual malaria mortality stands at 860,000. Needle-free delivery of vaccine to the skin holds promise for improved immunogenicity with lower doses of vaccine, in addition to significant logistical advantages. Va...

  2. An adenovirus vectored mucosal adjuvant augments protection of mice immunized intranasally with an adenovirus-vectored foot-and-mouth disease virus subunit vaccine.

    Science.gov (United States)

    Alejo, Diana M; Moraes, Mauro P; Liao, Xiaofen; Dias, Camila C; Tulman, Edan R; Diaz-San Segundo, Fayna; Rood, Debra; Grubman, Marvin J; Silbart, Lawrence K

    2013-04-26

    Foot-and-mouth disease virus (FMDV) is a highly contagious pathogen that causes severe morbidity and economic losses to the livestock industry in many countries. The oral and respiratory mucosae are the main ports of entry of FMDV, so the stimulation of local immunity in these tissues may help prevent initial infection and viral spread. E. coli heat-labile enterotoxin (LT) has been described as one of the few molecules that have adjuvant activity at mucosal surfaces. The objective of this study was to evaluate the efficacy of replication-defective adenovirus 5 (Ad5) vectors encoding either of two LT-based mucosal adjuvants, LTB or LTR72. These vectored adjuvants were delivered intranasally to mice concurrent with an Ad5-FMDV vaccine (Ad5-A24) to assess their ability to augment mucosal and systemic humoral immune responses to Ad5-A24 and protection against FMDV. Mice receiving Ad5-A24 plus Ad5-LTR72 had higher levels of mucosal and systemic neutralizing antibodies than those receiving Ad5-A24 alone or Ad5-A24 plus Ad5-LTB. The vaccine plus Ad5-LTR72 group also demonstrated 100% survival after intradermal challenge with a lethal dose of homologous FMDV serotype A24. These results suggest that Ad5-LTR72 could be used as an important tool to enhance mucosal and systemic immunity against FMDV and potentially other pathogens with a common route of entry. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Biomarkers of safety and immune protection for genetically modified live attenuated Leishmania vaccines against visceral leishmaniasis-Discovery and implications

    Directory of Open Access Journals (Sweden)

    Sreenivas eGannavaram

    2014-05-01

    Full Text Available Despite intense efforts there is no safe and efficacious vaccine against visceral leishmaniasis, which is fatal and endemic in many tropical countries. A major shortcoming in the vaccine development against blood borne parasitic agents such as Leishmania is the inadequate predictive power of the early immune responses mounted in the host against the experimental vaccines. Often immune correlates derived from in-bred animal models do not yield immune markers of protection that can be readily extrapolated to humans. The limited efficacy of vaccines based on DNA, sub-unit, heat killed parasites has led to the realization that acquisition of durable immunity against the protozoan parasites requires a controlled infection with a live attenuated organism. Recent success of irradiated malaria parasites as a vaccine candidate further strengthens this approach to vaccination. We developed several gene deletion mutants in L. donovani as potential live attenuated vaccines and reported extensively on the immunogenicity of LdCentrin1 deleted mutant in mice, hamsters and dogs. Additional limited studies using genetically modified live attenuated Leishmania parasites as vaccine candidates have been reported. However, for the live attenuated parasite vaccines, the primary barrier against widespread use remains the absence of clear biomarkers associated with protection and safety. Recent studies in evaluation of vaccines e.g., influenza and yellow fever vaccines, using systems biology tools demonstrated the power of such strategies in understanding the immunological mechanisms that underpin a protective phenotype. Applying similar tools in isolated human tissues such as PBMCs from healthy individuals infected with live attenuated parasites such as LdCen1-/- in vitro followed by human microarray hybridization experiments will enable us to understand how early vaccine-induced gene expression profiles and the associated immune responses are coordinately regulated

  4. Development of a duplex real-time RT-qPCR assay to monitor genome replication, gene expression and gene insert stability during in vivo replication of a prototype live attenuated canine distemper virus vector encoding SIV gag.

    Science.gov (United States)

    Coleman, John W; Wright, Kevin J; Wallace, Olivia L; Sharma, Palka; Arendt, Heather; Martinez, Jennifer; DeStefano, Joanne; Zamb, Timothy P; Zhang, Xinsheng; Parks, Christopher L

    2015-03-01

    Advancement of new vaccines based on live viral vectors requires sensitive assays to analyze in vivo replication, gene expression and genetic stability. In this study, attenuated canine distemper virus (CDV) was used as a vaccine delivery vector and duplex 2-step quantitative real-time RT-PCR (RT-qPCR) assays specific for genomic RNA (gRNA) or mRNA have been developed that concurrently quantify coding sequences for the CDV nucleocapsid protein (N) and a foreign vaccine antigen (SIV Gag). These amplicons, which had detection limits of about 10 copies per PCR reaction, were used to show that abdominal cavity lymphoid tissues were a primary site of CDV vector replication in infected ferrets, and importantly, CDV gRNA or mRNA was undetectable in brain tissue. In addition, the gRNA duplex assay was adapted for monitoring foreign gene insert genetic stability during in vivo replication by analyzing the ratio of CDV N and SIV gag genomic RNA copies over the course of vector infection. This measurement was found to be a sensitive probe for assessing the in vivo genetic stability of the foreign gene insert. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Mucosal delivery of a vectored RSV vaccine is safe and elicits protective immunity in rodents and nonhuman primates

    Directory of Open Access Journals (Sweden)

    Angiolo Pierantoni

    Full Text Available Respiratory Syncytial Virus (RSV is a leading cause of severe respiratory disease in infants and the elderly. No vaccine is presently available to address this major unmet medical need. We generated a new genetic vaccine based on chimpanzee Adenovirus (PanAd3-RSV and Modified Vaccinia Ankara RSV (MVA-RSV encoding the F, N, and M2-1 proteins of RSV, for the induction of neutralizing antibodies and broad cellular immunity. Because RSV infection is restricted to the respiratory tract, we compared intranasal (IN and intramuscular (M administration for safety, immunogenicity, and efficacy in different species. A single IN or IM vaccination completely protected BALB/c mice and cotton rats against RSV replication in the lungs. However, only IN administration could prevent infection in the upper respiratory tract. IM vaccination with MVA-RSV also protected cotton rats from lower respiratory tract infection in the absence of detectable neutralizing antibodies. Heterologous prime boost with PanAd3-RSV and MVA-RSV elicited high neutralizing antibody titers and broad T-cell responses in nonhuman primates. In addition, animals primed in the nose developed mucosal IgA against the F protein. In conclusion, we have shown that our vectored RSV vaccine induces potent cellular and humoral responses in a primate model, providing strong support for clinical testing.

  6. Intranasal boosting with an adenovirus-vectored vaccine markedly enhances protection by parenteral Mycobacterium bovis BCG immunization against pulmonary tuberculosis.

    Science.gov (United States)

    Santosuosso, Michael; McCormick, Sarah; Zhang, Xizhong; Zganiacz, Anna; Xing, Zhou

    2006-08-01

    Parenterally administered Mycobacterium bovis BCG vaccine confers only limited immune protection from pulmonary tuberculosis in humans. There is a need for developing effective boosting vaccination strategies. We examined a heterologous prime-boost regimen utilizing BCG as a prime vaccine and our recently described adenoviral vector expressing Ag85A (AdAg85A) as a boost vaccine. Since we recently demonstrated that a single intranasal but not intramuscular immunization with AdAg85A was able to induce potent protection from pulmonary Mycobacterium tuberculosis challenge in a mouse model, we compared the protective effects of parenteral and mucosal booster immunizations following subcutaneous BCG priming. Protection by BCG prime immunization was not effectively boosted by subcutaneous BCG or intramuscular AdAg85A. In contrast, protection by BCG priming was remarkably boosted by intranasal AdAg85A. Such enhanced protection by intranasal AdAg85A was correlated to the numbers of gamma interferon-positive CD4 and CD8 T cells residing in the airway lumen of the lung. Our study demonstrates that intranasal administration of AdAg85A represents an effective way to boost immune protection by parenteral BCG vaccination.

  7. Bacillus subtilis as a tool for vaccine development: from antigen factories to delivery vectors

    Directory of Open Access Journals (Sweden)

    Luís C.S. Ferreira

    2005-03-01

    Full Text Available Bacillus subtilis and some of its close relatives have a long history of industrial and biotechnological applications. Search for antigen expression systems based on recombinant B. subtilis strains sounds attractive both by the extensive genetic knowledge and the lack of an outer membrane, which simplify the secretion and purification of heterologous proteins. More recently, genetically modified B. subtilis spores have been described as indestructible delivery vehicles for vaccine antigens. Nonetheless both production and delivery of antigens by B. subtilis strains face some inherent obstacles, as unstable gene expression and reduced immunogenicity that, otherwise, can be overcome by already available gene technology approaches. In the present review we present the status of B. subtilis-based vaccine research, either as protein factories or delivery vectors, and discuss some alternatives for a better use of genetically modified strains.Bacillus subtilis e alguns de seus parentes mais próximos possuem uma longa história de aplicações industriais e biotecnológicas. A busca de sistemas de expressão de antígenos baseados em linhagens recombinants de B. subtilis mostra-se atrativa em função do conhecimento genético disponível e ausência de uma membrana externa, o que simplifica a secreção e a purificação de proteínas heterólogas. Mais recentemente, esporos geneticamente modificados de B. subtilis foram descritos com veículos indestrutíveis para o transporte de antígenos vacinais. Todavia a produção e o transporte de antígenos por linhagens de B. subtilis encontra obstáculos, como a expressão gênica instável e imunogenicidade reduzida, que podem ser superados com o auxílio de tecnologias genéticas atualmente disponíveis. Apresentamos nesta revisão o estado atual da pesquisa em vacinas baseadas em B. subtilis, empregado tanto como fábrica de proteínas ou veículos, e discute algumas alternativas para o uso mais

  8. Co-administration of live measles and yellow fever vaccines and inactivated pentavalent vaccines is associated with increased mortality compared with measles and yellow fever vaccines only. An observational study from Guinea-Bissau.

    Science.gov (United States)

    Fisker, Ane Bærent; Ravn, Henrik; Rodrigues, Amabelia; Østergaard, Marie Drivsholm; Bale, Carlito; Benn, Christine Stabell; Aaby, Peter

    2014-01-23

    Studies from low-income countries indicate that co-administration of inactivated diphtheria-tetanus-pertussis (DTP) vaccine and live attenuated measles vaccine (MV) is associated with increased mortality compared with receiving MV only. Pentavalent (DTP-H. Influenza type B-Hepatitis B) vaccine is replacing DTP in many low-income countries and yellow fever vaccine (YF) has been introduced to be given together with MV. Pentavalent and YF vaccines were introduced in Guinea-Bissau in 2008. We investigated whether co-administration of pentavalent vaccine with MV and yellow fever vaccine has similar negative effects. In 2007-2011, we conducted a randomised placebo-controlled trial of vitamin A at routine vaccination contacts among children aged 6-23 months in urban and rural Guinea-Bissau. In the present study, we included 2331 children randomised to placebo who received live vaccines only (MV or MV+YF) or a combination of live and inactivated vaccines (MV+DTP or MV+YF+pentavalent). Mortality was compared in Cox proportional hazards models stratified for urban/rural enrolment adjusted for age and unevenly distributed baseline factors. While DTP was still used 685 children received MV only and 358 MV+DTP; following the change in programme, 940 received MV+YF only and 348 MV+YF+pentavalent. During 6 months of follow-up, the adjusted mortality rate ratio (MRR) for co-administered live and inactivated vaccines compared with live vaccines only was 3.24 (1.20-8.73). For MV+YF+pentavalent compared with MV+YF only, the adjusted MRR was 7.73 (1.79-33.4). In line with previous studies of DTP, the present results indicate that pentavalent vaccine co-administered with MV and YF is associated with increased mortality. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Innovative in cellulo method as an alternative to in vivo neurovirulence test for the characterization and quality control of human live Yellow Fever virus vaccines: a pilot study

    OpenAIRE

    Da Costa , Anaelle; Prehaud , Christophe; Khou , Cécile; Pardigon , Nathalie; Saulnier , Aure; Nougarede , Nolwenn; Lafon , Monique

    2018-01-01

    International audience; Live attenuated vaccines have proved to be mostly valuable in the prevention of infectious diseases in humans, especially in developing countries. The safety and potency of vaccine, and the consistency of vaccine batch-to-batch manufacturing, must be proven before being administrated to humans. For now, the tests used to control vaccine safety largely involve animal testing. For live viral vaccines, regulations require suppliers to demonstrate the absence of neurovirul...

  10. Expression of the Surface Glycoproteins of Human Parainfluenza Virus Type 3 by Bovine Parainfluenza Virus Type 3, a Novel Attenuated Virus Vaccine Vector

    OpenAIRE

    Haller, Aurelia A.; Miller, Tessa; Mitiku, Misrach; Coelingh, Kathleen

    2000-01-01

    Bovine parainfluenza virus type 3 (bPIV3) is being evaluated as an intranasal vaccine for protection against human PIV3 (hPIV3). In young infants, the bPIV3 vaccine appears to be infectious, attenuated, immunogenic, and genetically stable, which are desirable characteristics for an RNA virus vector. To test the potential of the bPIV3 vaccine strain as a vector, an infectious DNA clone of bPIV3 was assembled and recombinant bPIV3 (r-bPIV3) was rescued. r-bPIV3 displayed a temperature-sensitive...

  11. AVIDITY EVALUATION OF LOCAL IgA ANTIBODIES IN PERSONS IMMUNIZED WITH LIVE INFLUENZA VACCINE

    Directory of Open Access Journals (Sweden)

    S. A. Donina

    2008-01-01

    Full Text Available Abstract. At present, immunogenicity evaluation of influenza vaccines is performed by quantitative assessment of increased serum antibodies. It was, however, shown that the degree of human defense against influenza is mostly related to their qualitative characteristics, i.e., avidity (functional activity. Leading role of local immunity is demonstrated in protection against influenza. Such immunity is mediated by IgA antibodies from mucosal airways. Meanwhile, the avidity issues for local antibodies still remain open.In present study, an attempt was undertaken to evaluate post-vaccination local immunological memory for influenza A virus, according to IgA antibodies from upper respiratory secretions. Two techniques were used to evaluate antibody avidity, that were previously applied for studying this phenomenon with serum imunoglobulins, i.e., a dynamic test (measurement of antigen-antibody reaction rates, and a test with urea, a chaotropic agent (avidity is determined as a strength of antigen-antibody complex. A total of 202 persons (18 to 20 years old were enrolled into the study.With both tests, a broad range of individual avidity values was observed for the antibodies. A significant cohort (up to 30 per cent of persons immunized with live influenza vaccine, showed sharply increased avidity of secretory IgA antibodies by both methods, along with accumulation of these immunoglobulins after vaccination. A reverse relationship is revealed between avidity levels of these antibodies before vaccination, and increase of this parameter post-immunization. The data present convincing arguments for specific renewal of local humoral immunological memory, as induced by live influenza vaccine. The study substantiates a necessity for application of the both tests in parallel, when determining avidity of secretory IgA antibodies. (Med. Immunol., vol. 10, N 4-5, pp 423-430.

  12. The recent progress in RSV vaccine technology.

    Science.gov (United States)

    Fretzayas, Andrew; Papadopoulou, Anna; Kotzia, Doxa; Moustaki, Maria

    2012-12-01

    The most effective way to control RSV infection would be the development of an expedient and safe vaccine. Subunit vaccines, live attenuated RSV vaccines, plasmid DNA vaccines have been tested either in human or in mouse models without reaching the ultimate goal of efficacy and safety, at least in humans. Viruses such as adenovirus, sendai virus, measles virus were also used as vectors for the generation of RSV vaccines with promising results in animal models. Recent patents describe new techniques for the generation of candidate vaccines. These patents include virus like particles as vaccine platforms, recombinant RSVs or modified RSV F protein as component of the vaccine. Despite the number of the candidate vaccines, the new RSV vaccines should overcome many obstacles before being established as effective vaccines for the control of RSV infections especially for the young infants who are more susceptible to the virus.

  13. Production and efficacy of an attenuated live vaccine against contagious ovine ecthyma

    Directory of Open Access Journals (Sweden)

    Attilio Pini

    2008-09-01

    Full Text Available Contagious ecthyma is caused by the orf virus, a member of the family Poxviridae, genus Parapoxvirus. Morbidity in affected sheep flocks is approximately 100%, while mortality varies between 1% and 10%. A live attenuated vaccine was produced by the Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise ‘G. Caporale’. Quality control was performed in accordance with the European Pharmacopoeia. A wild virus strain was attenuated through serial passages on primary chicken embryo fibroblast tissue cultures. The virus suspension was treated according to standard procedures and freeze dried. The immunising dose was 1 ml containing 104,5TCID50, administered intramuscularly. The safety of the vaccine was successfully tested by intramuscular inoculation of 20 susceptible sheep and 20 lambs with the routine dose, 10 times the immunising dose and two normal doses administered at seven-day intervals. The efficacy of the vaccine was tested using three groups of susceptible animals. The first group included 10 lambs and the second 10 adult sheep; the animals were immunised intramuscularly with 1 ml of the reconstituted vaccine. The third group, used as controls, included five sheep and five lambs. Serological reactivity was monitored by indirect enzyme-linked immunosorbent assay (ELISA. The animals were challenged 30 days later with a pathogenic strain administered intradermally along the labial area. Vaccinated animals did not show any clinical signs of disease, whereas all the controls developed typical signs of contagious ecthyma. To confirm the efficacy of the vaccine, a field trial was conducted in four flocks affected by the disease. The trial showed that the vaccine was able to block the normal course of the disease and induce rapid recovery.

  14. Extended Preclinical Safety, Efficacy and Stability Testing of a Live-attenuated Chikungunya Vaccine Candidate.

    Directory of Open Access Journals (Sweden)

    Kenneth S Plante

    Full Text Available We recently described a new, live-attenuated vaccine candidate for chikungunya (CHIK fever, CHIKV/IRES. This vaccine was shown to be well attenuated, immunogenic and efficacious in protecting against CHIK virus (CHIKV challenge of mice and nonhuman primates. To further evaluate its preclinical safety, we compared CHIKV/IRES distribution and viral loads in interferon-α/β receptor-incompetent A129 mice to another CHIK vaccine candidate, 181/clone25, which proved highly immunogenic but mildly reactive in human Phase I/II clinical trials. Compared to wild-type CHIK virus, (wt-CHIKV, both vaccines generated lower viral loads in a wide variety of tissues and organs, including the brain and leg muscle, but CHIKV/IRES exhibited marked restrictions in dissemination and viral loads compared to 181/clone25, and was never found outside the blood, spleen and muscle. Unlike wt-CHIKV, which caused disrupted splenic architecture and hepatic lesions, histopathological lesions were not observed in animals infected with either vaccine strain. To examine the stability of attenuation, both vaccines were passaged 5 times intracranially in infant A129 mice, then assessed for changes in virulence by comparing parental and passaged viruses for footpad swelling, weight stability and survival after subcutaneous infection. Whereas strain 181/clone25 p5 underwent a significant increase in virulence as measured by weight loss (from 30% and mortality (from 0 to 100%, CHIKV/IRES underwent no detectible change in any measure of virulence (no significant weight loss and no mortality. These data indicate greater nonclinical safety of the CHIKV/IRES vaccine candidate compared to 181/clone25, further supporting its eligibility for human testing.

  15. Herpes zoster vaccine live: A 10 year review of post-marketing safety experience.

    Science.gov (United States)

    Willis, English D; Woodward, Meredith; Brown, Elizabeth; Popmihajlov, Zoran; Saddier, Patricia; Annunziato, Paula W; Halsey, Neal A; Gershon, Anne A

    2017-12-19

    Zoster vaccine is a single dose live, attenuated vaccine (ZVL) indicated for individuals ≥50 years-old for the prevention of herpes zoster (HZ). Safety data from clinical trials and post-licensure studies provided reassurance that ZVL is generally safe and well tolerated. The objective of this review was to provide worldwide post-marketing safety information following 10 years of use and >34 million doses distributed. All post-marketing adverse experience (AE) reports received worldwide between 02-May-2006 and 01-May-2016 from healthcare professionals following vaccination with ZVL and submitted to the MSD AE global safety database, were analyzed. A total of 23,556 AE reports, 93% non-serious, were reported. Local injection site reactions (ISRs), with a median time-to-onset of 2 days, were the most frequently reported AEs followed by HZ. The majority of HZ reports were reported within 2 weeks of vaccination and considered, based on time-to-onset, pathogenesis of HZ, and data from clinical trials, to be caused by wild-type varicella-zoster virus (VZV). HZ confirmed by PCR analysis to be VZV Oka/Merck vaccine-strain was identified in an immunocompetent individual 8 months postvaccination and in 4 immunocompromised individuals. Disseminated HZ was reported very rarely (marketing use, was favorable and consistent with that observed in clinical trials and post-licensure studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Tackling the issue of environmental survival of live Salmonella Typhimurium vaccines: deletion of the lon gene.

    Science.gov (United States)

    Leyman, Bregje; Boyen, Filip; Van Parys, Alexander; Verbrugghe, Elin; Haesebrouck, Freddy; Pasmans, Frank

    2012-12-01

    Vaccination is an important measure to control Salmonella contamination in the meat production chain. A previous study showed that both the ΔrfaJ and ΔrfaL strains are suitable markers and allow serological differentiation of infected and vaccinated animals. The aim of this study was to verify whether deletion of the lon gene in a Salmonella Typhimurium ΔrfaJ marker strain resulted in decreased environmental survival. Our results indicate that deletion of the lon gene in the ΔrfaJ strain did not affect invasiveness in IPEC-J2 cells and resulted in an increased susceptibility to UV, disinfectants (such as hydrogen peroxide and tosylchloramide sodium) and citric acid. Immunization of pigs with inactivated ΔrfaJ or ΔlonΔrfaJ vaccines allowed differentiation of infected and vaccinated pigs. Furthermore, deletion of the lon gene did not reduce the protection conferred by live wild type or ΔrfaJ vaccines against subsequent challenge with a virulent Salmonella Typhimurium strain in BALB/c mice. Based on our results in mice, we conclude that deletion of lon in ΔrfaJ contributes to environmental safety of the ΔrfaJ DIVA strain. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Improved vaccine protection against retrovirus infection after co-administration of adenoviral vectors encoding viral antigens and type I interferon subtypes

    Directory of Open Access Journals (Sweden)

    Groitl Peter

    2011-09-01

    Full Text Available Abstract Background Type I interferons (IFNs exhibit direct antiviral effects, but also distinct immunomodulatory properties. In this study, we analyzed type I IFN subtypes for their effect on prophylactic adenovirus-based anti-retroviral vaccination of mice against Friend retrovirus (FV or HIV. Results Mice were vaccinated with adenoviral vectors encoding FV Env and Gag proteins alone or in combination with vectors encoding IFNα1, IFNα2, IFNα4, IFNα5, IFNα6, IFNα9 or IFNβ. Only the co-administration of adenoviral vectors encoding IFNα2, IFNα4, IFNα6 and IFNα9 resulted in strongly improved immune protection of vaccinated mice from subsequent FV challenge infection with high control over FV-induced splenomegaly and reduced viral loads. The level of protection correlated with augmented virus-specific CD4+ T cell responses and enhanced antibody titers. Similar results were obtained when mice were vaccinated against HIV with adenoviral vectors encoding HIV Env and Gag-Pol in combination with various type I IFN encoding vectors. Here mainly CD4+ T cell responses were enhanced by IFNα subtypes. Conclusions Our results indicate that certain IFNα subtypes have the potential to improve the protective effect of adenovirus-based vaccines against retroviruses. This correlated with augmented virus-specific CD4+ T cell and antibody responses. Thus, co-expression of select type I IFNs may be a valuable tool for the development of anti-retroviral vaccines.

  18. Microneedle-mediated immunization of an adenovirus-based malaria vaccine enhances antigen-specific antibody immunity and reduces anti-vector responses compared to the intradermal route.

    Science.gov (United States)

    Carey, John B; Vrdoljak, Anto; O'Mahony, Conor; Hill, Adrian V S; Draper, Simon J; Moore, Anne C

    2014-08-21

    Substantial effort has been placed in developing efficacious recombinant attenuated adenovirus-based vaccines. However induction of immunity to the vector is a significant obstacle to its repeated use. Here we demonstrate that skin-based delivery of an adenovirus-based malaria vaccine, HAdV5-PyMSP1₄₂, to mice using silicon microneedles induces equivalent or enhanced antibody responses to the encoded antigen, however it results in decreased anti-vector responses, compared to intradermal delivery. Microneedle-mediated vaccine priming and resultant induction of low anti-vector antibody titres permitted repeated use of the same adenovirus vaccine vector. This resulted in significantly increased antigen-specific antibody responses in these mice compared to ID-treated mice. Boosting with a heterologous vaccine; MVA-PyMSP1₄₂ also resulted in significantly greater antibody responses in mice primed with HAdV5-PyMSP1₄₂ using MN compared to the ID route. The highest protection against blood-stage malaria challenge was observed when a heterologous route of immunization (MN/ID) was used. Therefore, microneedle-mediated immunization has potential to both overcome some of the logistic obstacles surrounding needle-and-syringe-based immunization as well as to facilitate the repeated use of the same adenovirus vaccine thereby potentially reducing manufacturing costs of multiple vaccines. This could have important benefits in the clinical ease of use of adenovirus-based immunization strategies.

  19. Microneedle-mediated immunization of an adenovirus-based malaria vaccine enhances antigen-specific antibody immunity and reduces anti-vector responses compared to the intradermal route

    Science.gov (United States)

    Carey, John B.; Vrdoljak, Anto; O'Mahony, Conor; Hill, Adrian V. S.; Draper, Simon J.; Moore, Anne C.

    2014-01-01

    Substantial effort has been placed in developing efficacious recombinant attenuated adenovirus-based vaccines. However induction of immunity to the vector is a significant obstacle to its repeated use. Here we demonstrate that skin-based delivery of an adenovirus-based malaria vaccine, HAdV5-PyMSP142, to mice using silicon microneedles induces equivalent or enhanced antibody responses to the encoded antigen, however it results in decreased anti-vector responses, compared to intradermal delivery. Microneedle-mediated vaccine priming and resultant induction of low anti-vector antibody titres permitted repeated use of the same adenovirus vaccine vector. This resulted in significantly increased antigen-specific antibody responses in these mice compared to ID-treated mice. Boosting with a heterologous vaccine; MVA-PyMSP142 also resulted in significantly greater antibody responses in mice primed with HAdV5-PyMSP142 using MN compared to the ID route. The highest protection against blood-stage malaria challenge was observed when a heterologous route of immunization (MN/ID) was used. Therefore, microneedle-mediated immunization has potential to both overcome some of the logistic obstacles surrounding needle-and-syringe-based immunization as well as to facilitate the repeated use of the same adenovirus vaccine thereby potentially reducing manufacturing costs of multiple vaccines. This could have important benefits in the clinical ease of use of adenovirus-based immunization strategies. PMID:25142082

  20. Effect of different adjuvant formulations on the immunogenicity and protective effect of a live Mycoplasma hyopneumoniae vaccine after intramuscular inoculation.

    Science.gov (United States)

    Xiong, Qiyan; Wei, Yanna; Xie, Haidong; Feng, Zhixin; Gan, Yuan; Wang, Chunlai; Liu, Maojun; Bai, Fangfang; Xie, Fang; Shao, Guoqing

    2014-06-05

    Mycoplasma hyopneumoniae (M. hyopneumoniae) vaccine strain 168 is an intrapulmonically injected attenuated live vaccine that is available in the Chinese market. The aim of this study was to develop suitable adjuvants for this live vaccine to provide effective protection after intramuscular inoculation. Several adjuvant components were screened to assess their toxicity for the live vaccine, and various adjuvant formulations were then designed and prepared. Vaccines supplemented with these adjuvants were used to immunize mice intramuscularly to assess the capacity of the adjuvants to induce a specific immune response. The screened formulations were then evaluated in pigs. Seven of the eight adjuvant components did not affect the viability of the live vaccine, and seven different adjuvant formulations were then designed. In mice, the ISCOM-matrix adjuvant and the levamisole-chitosan mixture adjuvant significantly enhanced serum IgG responses against M. hyopneumoniae, while lymphocyte proliferation was enhanced by the ISCOM-matrix adjuvant, the carbomer-astragalus polysaccharide mixture adjuvant and an oil-in-water emulsion adjuvant. These four adjuvants were evaluated in pigs. Enhancement of specific lymphocyte proliferation responses was observed in the groups vaccinated with the ISCOM-matrix adjuvant and the carbomer-astragalus polysaccharide mixture adjuvant. Significant enhancement of serum IgG antibody production was observed before challenge in pigs vaccinated with the carbomer-astragalus polysaccharide mixture adjuvant and the levamisole-chitosan mixture adjuvant, while after challenge, all of the animals that received vaccines containing adjuvants had higher antibody concentrations against M. hyopneumoniae than unvaccinated animals. Animals inoculated with a vaccine containing the ISCOM-matrix adjuvant (median score 3.57) or the carbomer-astragalus polysaccharide mixture adjuvant (median score 5.28) had reduced lesion scores compared to unvaccinated animals

  1. Protective Immunity against Tularemia Provided by an Adenovirus-Vectored Vaccine Expressing Tul4 of Francisella tularensis

    OpenAIRE

    Kaur, Ravinder; Chen, Shan; Arévalo, Maria T.; Xu, Qingfu; Chen, Yanping; Zeng, Mingtao

    2012-01-01

    Francisella tularensis, a category A bioterrorism agent, is a highly infectious organism that is passed on via skin contact and inhalation routes. A live attenuated vaccine strain (LVS) has been developed, but it has not been licensed for public use by the FDA due to safety concerns. Thus, there exists a need for a safer and improved vaccine. In this study, we have constructed a replication-incompetent adenovirus, Ad/opt-Tul4, carrying a codon-optimized gene for expression of a membrane prote...

  2. Immunogenicity and Safety of the HZ/su Adjuvanted Herpes Zoster Subunit Vaccine in Adults Previously Vaccinated With a Live Attenuated Herpes Zoster Vaccine.

    Science.gov (United States)

    Grupping, Katrijn; Campora, Laura; Douha, Martine; Heineman, Thomas C; Klein, Nicola P; Lal, Himal; Peterson, James; Vastiau, Ilse; Oostvogels, Lidia

    2017-12-12

    Protection against herpes zoster (HZ) induced by the live attenuated zoster vaccine Zostavax (ZVL) wanes within 3-7 years. Revaccination may renew protection. We assessed whether (re)vaccination with the adjuvanted HZ subunit vaccine candidate (HZ/su) induced comparable immune responses in previous ZVL recipients and ZVL-naive individuals (HZ-NonVac). In an open-label, multicenter study, adults ≥65 years of age, vaccinated with ZVL ≥5 years previously (HZ-PreVac), were matched to ZVL-naive adults (HZ-NonVac). Participants received 2 doses of HZ/su 2 months apart. The primary objective of noninferiority of the humoral immune response 1 month post-dose 2 was considered demonstrated if the upper limit of the 95% confidence interval (CI) of the adjusted anti-glycoprotein E geometric mean concentration (GMC) ratio of HZ-NonVac over HZ-PreVac was <1.5. HZ/su cellular immunogenicity, reactogenicity, and safety were also assessed. In 430 participants, humoral immune response to HZ/su was noninferior in HZ-PreVac compared with HZ-NonVac (adjusted GMC ratio, 1.04 [95% CI, .92-1.17]). Cellular immunogenicity, reactogenicity, and safety appeared to be comparable between groups. HZ/su was well-tolerated, with no safety concerns raised within 1 month post-dose 2. HZ/su induces a strong immune response irrespective of prior vaccination with ZVL, and may be an attractive option to revaccinate prior ZVL recipients. NCT02581410. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  3. Prime-booster vaccination of cattle with an influenza viral vector Brucella abortus vaccine induces a long-term protective immune response against Brucella abortus infection.

    Science.gov (United States)

    Tabynov, Kaissar; Yespembetov, Bolat; Ryskeldinova, Sholpan; Zinina, Nadezhda; Kydyrbayev, Zhailaubay; Kozhamkulov, Yerken; Inkarbekov, Dulat; Sansyzbay, Abylai

    2016-01-20

    This study analyzed the duration of the antigen-specific humoral and T-cell immune responses and protectiveness of a recently-developed influenza viral vector Brucella abortus (Flu-BA) vaccine expressing Brucella proteins Omp16 and L7/L12 and containing the adjuvant Montadine Gel01 in cattle. At 1 month post-booster vaccination (BV), both humoral (up to 3 months post-BV; GMT IgG ELISA titer 214±55 to 857±136, with a prevalence of IgG2a over IgG1 isotype antibodies) and T-cell immune responses were observed in vaccinated heifers (n=35) compared to control animals (n=35, injected with adjuvant/PBS only). A pronounced T-cell immune response was induced and maintained for 12 months post-BV, as indicated by the lymphocyte stimulation index (2.7±0.4 to 10.1±0.9 cpm) and production of IFN-γ (13.7±1.7 to 40.0±3.0 ng/ml) at 3, 6, 9, and 12 months post-BV. Prime-boost vaccination provided significant protection against B. abortus infection at 3, 6, 9 and 12 months (study duration) post-BV (7 heifers per time point; alpha=0.03-0.01 vs. control group). Between 57.1 and 71.4% of vaccinated animals showed no signs of B. abortus infection (or Brucella isolation) at 3, 6, 9 and 12 months post-BV; the severity of infection, as indicated by the index of infection (P=0.0003 to Brucella colonization (P=0.03 to abortus infection was also observed among pregnant vaccinated heifers (alpha=0.03), as well as their fetuses and calves (alpha=0.01), for 12 months post-BV. Additionally, 71.4% of vaccinated heifers calved successfully whereas all pregnant control animals aborted (alpha=0.01). Prime-boost vaccination of cattle with Flu-BA induces an antigen-specific humoral and pronounced T cell immune response and most importantly provides good protectiveness, even in pregnant heifers, for at least 12 months post-BV. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Concomitant use of an oral live pentavalent human-bovine reassortant rotavirus vaccine with licensed parenteral pediatric vaccines in the United States.

    Science.gov (United States)

    Rodriguez, Zoe M; Goveia, Michelle G; Stek, Jon E; Dallas, Michael J; Boslego, John W; DiNubile, Mark J; Heaton, Penny M

    2007-03-01

    A live pentavalent rotavirus vaccine (PRV) containing 5 human-bovine (WC3) reassortants expressing human serotypes G1, G2, G3, G4 and P1A[8] was evaluated in a blinded, placebo-controlled study. Possible interactions between PRV and concomitantly administered licensed pediatric vaccines were investigated in a United States-based nested substudy (Concomitant Use Study) of the Rotavirus Efficacy and Safety Trial. From 2002 to 2003, healthy infants approximately 6 to 12 weeks of age at entry were randomized to receive either 3 oral doses of PRV or placebo at 4- to 10-week intervals. Subjects were also to receive combined Haemophilus influenzae type b and hepatitis B vaccine (2 doses), diphtheria and tetanus toxoids and acellular pertussis vaccine (3 doses), inactivated poliovirus vaccine (2 doses) and pneumococcal conjugate vaccine (3 doses) on the same day; oral poliovirus vaccine was not administered. Immunogenicity was assessed by measuring antibody responses to PRV and antigens contained in the licensed vaccines. Cases of rotavirus gastroenteritis were defined by forceful vomiting and/or -3 watery or looser-than-normal stools within a 24-hour period, and detection of rotavirus antigen in the stool. Safety was assessed by reporting of adverse events using diary cards. The Concomitant Use Study enrolled 662 subjects in the PRV group and 696 subjects in the placebo group. For the 17 antigens in the concomitantly administered vaccines, antibody responses were similar in PRV and placebo recipients, except for moderately diminished antibody responses to the pertactin component of pertussis vaccine. Efficacy of PRV against rotavirus gastroenteritis of any severity was 89.5% (95% CI = 26.5-99.8%). PRV was generally well tolerated when given concomitantly with the prespecified vaccines. In this study, antibody responses to the concomitantly administered vaccines were generally similar in PRV and placebo recipients. PRV was efficacious and well tolerated when given

  5. Cationic lipid-formulated DNA vaccine against hepatitis B virus: immunogenicity of MIDGE-Th1 vectors encoding small and large surface antigen in comparison to a licensed protein vaccine.

    Directory of Open Access Journals (Sweden)

    Anne Endmann

    Full Text Available Currently marketed vaccines against hepatitis B virus (HBV based on the small (S hepatitis B surface antigen (HBsAg fail to induce a protective immune response in about 10% of vaccinees. DNA vaccination and the inclusion of PreS1 and PreS2 domains of HBsAg have been reported to represent feasible strategies to improve the efficacy of HBV vaccines. Here, we evaluated the immunogenicity of SAINT-18-formulated MIDGE-Th1 vectors encoding the S or the large (L protein of HBsAg in mice and pigs. In both animal models, vectors encoding the secretion-competent S protein induced stronger humoral responses than vectors encoding the L protein, which was shown to be retained mainly intracellularly despite the presence of a heterologous secretion signal. In pigs, SAINT-18-formulated MIDGE-Th1 vectors encoding the S protein elicited an immune response of the same magnitude as the licensed protein vaccine Engerix-B, with S protein-specific antibody levels significantly higher than those considered protective in humans, and lasting for at least six months after the third immunization. Thus, our results provide not only the proof of concept for the SAINT-18-formulated MIDGE-Th1 vector approach but also confirm that with a cationic-lipid formulation, a DNA vaccine at a relatively low dose can elicit an immune response similar to a human dose of an aluminum hydroxide-adjuvanted protein vaccine in large animals.

  6. A novel multiplex poliovirus binding inhibition assay applicable for large serosurveillance and vaccine studies, without the use of live poliovirus.

    NARCIS (Netherlands)

    Schepp, Rutger M; Berbers, Guy A M; Ferreira, José A; Reimerink, Johan H; van der Klis, Fiona R

    2017-01-01

    Large-scale serosurveillance or vaccine studies for poliovirus using the "gold standard" WHO neutralisation test (NT) are very laborious and time consuming. With the polio eradication at hand and with the removal of live attenuated Sabin strains from the oral poliovirus vaccine (OPV), starting with

  7. Immunogenicity of an Intranasally Administered Modified Live Canine Parvovirus Type 2b Vaccine in Pups with Maternally Derived Antibodies

    Science.gov (United States)

    Martella, Vito; Cavalli, Alessandra; Decaro, Nicola; Elia, Gabriella; Desario, Costantina; Campolo, Marco; Bozzo, Giancarlo; Tarsitano, Elvira; Buonavoglia, Canio

    2005-01-01

    The ability of a modified live canine parvovirus type 2b vaccine to elicit active immunization in pups with maternally derived antibodies (MDA) by intranasal administration was evaluated. The vaccine induced seroconversion in 100% of pups with MDA titers of ≤80 and in 51.6% of pups with titers between 160 and 320. PMID:16210491

  8. Immunogenicity of an Intranasally Administered Modified Live Canine Parvovirus Type 2b Vaccine in Pups with Maternally Derived Antibodies

    OpenAIRE

    Martella, Vito; Cavalli, Alessandra; Decaro, Nicola; Elia, Gabriella; Desario, Costantina; Campolo, Marco; Bozzo, Giancarlo; Tarsitano, Elvira; Buonavoglia, Canio

    2005-01-01

    The ability of a modified live canine parvovirus type 2b vaccine to elicit active immunization in pups with maternally derived antibodies (MDA) by intranasal administration was evaluated. The vaccine induced seroconversion in 100% of pups with MDA titers of ≤80 and in 51.6% of pups with titers between 160 and 320.

  9. Immunogenicity of an intranasally administered modified live canine parvovirus type 2b vaccine in pups with maternally derived antibodies.

    Science.gov (United States)

    Martella, Vito; Cavalli, Alessandra; Decaro, Nicola; Elia, Gabriella; Desario, Costantina; Campolo, Marco; Bozzo, Giancarlo; Tarsitano, Elvira; Buonavoglia, Canio

    2005-10-01

    The ability of a modified live canine parvovirus type 2b vaccine to elicit active immunization in pups with maternally derived antibodies (MDA) by intranasal administration was evaluated. The vaccine induced seroconversion in 100% of pups with MDA titers of < or = 80 and in 51.6% of pups with titers between 160 and 320.

  10. Complete Genome Sequence of the Goatpox Virus Strain Gorgan Obtained Directly from a Commercial Live Attenuated Vaccine

    Science.gov (United States)

    Mathijs, Elisabeth; Vandenbussche, Frank; Haegeman, Andy; Al-Majali, Ahmad; De Clercq, Kris

    2016-01-01

    This is a report of the complete genome sequence of the goatpox virus strain Gorgan, which was obtained directly from a commercial live attenuated vaccine (Caprivac, Jordan Bio-Industries Centre). PMID:27738031

  11. Novel bivalent vectored vaccine for control of myxomatosis and rabbit haemorrhagic disease.

    Science.gov (United States)

    Spibey, N; McCabe, V J; Greenwood, N M; Jack, S C; Sutton, D; van der Waart, L

    2012-03-24

    A novel, recombinant myxoma virus-rabbit haemorrhagic disease virus (RHDV) vaccine has been developed for the prevention of myxomatosis and rabbit haemorrhagic disease (RHD). A number of laboratory studies are described illustrating the safety and efficacy of the vaccine following subcutaneous administration in laboratory rabbits from four weeks of age onwards. In these studies, both vaccinated and unvaccinated control rabbits were challenged using pathogenic strains of RHD and myxoma viruses, and 100 per cent of the vaccinated rabbits were protected against both myxomatosis and RHD.

  12. Serologic response of roosters to gradient dosage levels of a commercially available live F strain-derived Mycoplasma gallisepticum vaccine over time

    Science.gov (United States)

    Spray application is a commonly used time- and labor-efficient means to deliver live Mycoplasma gallisepticum (MG) vaccine to laying hens in commercial production facilities. The dosage of vaccine received by spray vaccinated birds can vary due to variation in the spray plume and vaccine suspension...

  13. Safety issues from a Phase 3 clinical trial of a live-attenuated chimeric yellow fever tetravalent dengue vaccine.

    Science.gov (United States)

    Halstead, Scott B

    2018-02-26

    A tetravalent live-attenuated 3-dose vaccine composed of chimeras of yellow fever 17D and the four dengue viruses (CYD, also called Dengvaxia) completed phase 3 clinical testing in over 35,000 children leading to a recommendation that vaccine be administered to >/ = 9 year-olds residing in highly dengue- endemic countries. When clinical trial results were assessed 2 years after the first dose, vaccine efficacy among seropositives was high, but among seronegatives efficacy was marginal. Breakthrough dengue hospitalizations of vaccinated children occurred continuously over a period of 4-5 years post 3rd dose in an age distribution suggesting these children had been vaccinated when seronegative. This surmise was validated recently when the manufacturer reported that dengue NS1 IgG antibodies were absent in sera from hospitalized vaccinated children, an observation consistent with their having received Dengvaxia when seronegative. Based upon published efficacy data and in compliance with initial published recommendations by the manufacturer and WHO the Philippine government undertook to vaccinate 800,000-plus 9 year-olds starting in April 2016. Eighteen months later, dengue hospitalizations and a deaths were reported among vaccinated children. The benefits of administering Dengvaxia predicted by the manufacturer, WHO and others derive from scoring dengue hospitalizations of vaccinated children as vaccine failures rather than as vaccine enhanced dengue disease. Recommended regimens for administration of Dengvaxia should have been structured to warn of and avoid serious adverse events.

  14. Vaccination status of people living with HIV/AIDS in outpatient care in Fortaleza, Ceará, Brazil

    Directory of Open Access Journals (Sweden)

    Gilmara Holanda da Cunha

    2016-09-01

    Full Text Available Antiretroviral therapy has increased the survival of patients with HIV/AIDS, thus necessitating health promotion practice with immunization. Vaccines are critical components for protecting people living with HIV/AIDS (PLWHA. The purpose of study was to analyze the vaccination status of PLWHA in outpatient care in Fortaleza, Ceará, Brazil. Cross-sectional study performed from June 2014 to June 2015. The screening was done with patients in antiretroviral therapy, 420 patients underwent screening, but only 99 met the inclusion criteria. Data were collected for interviews using forms to characterize sociodemographic, clinical and vaccination situations. Only 14 patients had complete vaccination schedules. The most used vaccines were hepatitis B, influenza vaccine and 23-valent pneumococcal. There was no difference between men and women regarding the proportion of PLWHA with full vaccination schedule or between sex, skin color, marital status, sexual orientation, religion or occupational status. There was no difference between having or not having a complete vaccination schedule and age, years of education, family income or number of hospitalizations. CD4+ T-cells count of patients with incomplete immunization was lower than patients with complete immunization. Health education strategies can be done individually or in groups to explain the importance of vaccination and to remind about doses to be administered. Most patients did not have proper adherence to vaccination schedules, especially due to lack of guidance. Results implied that education in health is important for vaccination adhesion, knowledge of adverse events and continuation of schemes.

  15. Pan-Influenza A Protection by Prime-Boost Vaccination with Cold-Adapted Live-Attenuated Influenza Vaccine in a Mouse Model.

    Science.gov (United States)

    Jang, Yo Han; Kim, Joo Young; Byun, Young Ho; Son, Ahyun; Lee, Jeong-Yoon; Lee, Yoon Jae; Chang, Jun; Seong, Baik Lin

    2018-01-01

    Influenza virus infections continually pose a major public health threat with seasonal epidemics and sporadic pandemics worldwide. While currently licensed influenza vaccines provide only strain-specific protection, antigenic drift and shift occasionally render the viruses resistant to the host immune responses, which highlight the need for a vaccine that provides broad protection against multiple subtypes. In this study, we suggest a vaccination strategy using cold-adapted, live attenuated influenza vaccines (CAIVs) to provide a broad, potent, and safe cross-protection covering antigenically distinct hemagglutinin (HA) groups 1 and 2 influenza viruses. Using a mouse model, we tested different prime-boost combinations of CAIVs for their ability to induce humoral and T-cell responses, and protective efficacy against H1 and H5 (HA group 1) as well as H3 and H7 (HA group 2) influenza viruses. Notably, even in the absence of antibody-mediated neutralizing activity or HA inhibitory activity in vitro , CAIVs provided a potent protection against heterologous and heterosubtypic lethal challenges in vivo . Heterologous combination of prime (H1)-boost (H5) vaccine strains showed the most potent cross-protection efficacy. In vivo depletion experiments demonstrated not only that T cells and natural killer cells contributed to the cross-protection, but also the involvement of antibody-dependent mechanisms for the cross-protection. Vaccination-induced antibodies did not enhance the infectivity of heterologous viruses, and prime vaccination did not interfere with neutralizing antibody generation by the boost vaccination, allaying vaccine safety concerns associated with heterogeneity between the vaccines and challenge strains. Our data show that CAIV-based strategy can serve as a simple but powerful option for developing a "truly" universal influenza vaccine providing pan-influenza A protection, which has not been achieved yet by other vaccine strategies. The promising results

  16. Pan-Influenza A Protection by Prime–Boost Vaccination with Cold-Adapted Live-Attenuated Influenza Vaccine in a Mouse Model

    Science.gov (United States)

    Jang, Yo Han; Kim, Joo Young; Byun, Young Ho; Son, Ahyun; Lee, Jeong-Yoon; Lee, Yoon Jae; Chang, Jun; Seong, Baik Lin

    2018-01-01

    Influenza virus infections continually pose a major public health threat with seasonal epidemics and sporadic pandemics worldwide. While currently licensed influenza vaccines provide only strain-specific protection, antigenic drift and shift occasionally render the viruses resistant to the host immune responses, which highlight the need for a vaccine that provides broad protection against multiple subtypes. In this study, we suggest a vaccination strategy using cold-adapted, live attenuated influenza vaccines (CAIVs) to provide a broad, potent, and safe cross-protection covering antigenically distinct hemagglutinin (HA) groups 1 and 2 influenza viruses. Using a mouse model, we tested different prime–boost combinations of CAIVs for their ability to induce humoral and T-cell responses, and protective efficacy against H1 and H5 (HA group 1) as well as H3 and H7 (HA group 2) influenza viruses. Notably, even in the absence of antibody-mediated neutralizing activity or HA inhibitory activity in vitro, CAIVs provided a potent protection against heterologous and heterosubtypic lethal challenges in vivo. Heterologous combination of prime (H1)–boost (H5) vaccine strains showed the most potent cross-protection efficacy. In vivo depletion experiments demonstrated not only that T cells and natural killer cells contributed to the cross-protection, but also the involvement of antibody-dependent mechanisms for the cross-protection. Vaccination-induced antibodies did not enhance the infectivity of heterologous viruses, and prime vaccination did not interfere with neutralizing antibody generation by the boost vaccination, allaying vaccine safety concerns associated with heterogeneity between the vaccines and challenge strains. Our data show that CAIV-based strategy can serve as a simple but powerful option for developing a “truly” universal influenza vaccine providing pan-influenza A protection, which has not been achieved yet by other vaccine strategies. The promising

  17. Biomarkers of safety and immune protection for genetically modified live attenuated leishmania vaccines against visceral leishmaniasis - discovery and implications.

    Science.gov (United States)

    Gannavaram, Sreenivas; Dey, Ranadhir; Avishek, Kumar; Selvapandiyan, Angamuthu; Salotra, Poonam; Nakhasi, Hira L

    2014-01-01

    Despite intense efforts there is no safe and efficacious vaccine against visceral leishmaniasis, which is fatal and endemic in many tropical countries. A major shortcoming in the vaccine development against blood-borne parasitic agents such as Leishmania is the inadequate predictive power of the early immune responses mounted in the host against the experimental vaccines. Often immune correlates derived from in-bred animal models do not yield immune markers of protection that can be readily extrapolated to humans. The limited efficacy of vaccines based on DNA, subunit, heat killed parasites has led to the realization that acquisition of durable immunity against the protozoan parasites requires a controlled infection with a live attenuated organism. Recent success of irradiated malaria parasites as a vaccine candidate further strengthens this approach to vaccination. We developed several gene deletion mutants in Leishmania donovani as potential live attenuated vaccines and reported extensively on the immunogenicity of LdCentrin1 deleted mutant in mice, hamsters, and dogs. Additional limited studies using genetically modified live attenuated Leishmania parasites as vaccine candidates have been reported. However, for the live attenuated parasite vaccines, the primary barrier against widespread use remains the absence of clear biomarkers associated with protection and safety. Recent studies in evaluation of vaccines, e.g., influenza and yellow fever vaccines, using systems biology tools demonstrated the power of such strategies in understanding the immunological mechanisms that underpin a protective phenotype. Applying similar tools in isolated human tissues such as PBMCs from healthy individuals infected with live attenuated parasites such as LdCen(-/-) in vitro followed by human microarray hybridization experiments will enable us to understand how early vaccine-induced gene expression profiles and the associated immune responses are coordinately regulated in normal

  18. Biomarkers of Safety and Immune Protection for Genetically Modified Live Attenuated Leishmania Vaccines Against Visceral Leishmaniasis – Discovery and Implications

    Science.gov (United States)

    Gannavaram, Sreenivas; Dey, Ranadhir; Avishek, Kumar; Selvapandiyan, Angamuthu; Salotra, Poonam; Nakhasi, Hira L.

    2014-01-01

    Despite intense efforts there is no safe and efficacious vaccine against visceral leishmaniasis, which is fatal and endemic in many tropical countries. A major shortcoming in the vaccine development against blood-borne parasitic agents such as Leishmania is the inadequate predictive power of the early immune responses mounted in the host against the experimental vaccines. Often immune correlates derived from in-bred animal models do not yield immune markers of protection that can be readily extrapolated to humans. The limited efficacy of vaccines based on DNA, subunit, heat killed parasites has led to the realization that acquisition of durable immunity against the protozoan parasites requires a controlled infection with a live attenuated organism. Recent success of irradiated malaria parasites as a vaccine candidate further strengthens this approach to vaccination. We developed several gene deletion mutants in Leishmania donovani as potential live attenuated vaccines and reported extensively on the immunogenicity of LdCentrin1 deleted mutant in mice, hamsters, and dogs. Additional limited studies using genetically modified live attenuated Leishmania parasites as vaccine candidates have been reported. However, for the live attenuated parasite vaccines, the primary barrier against widespread use remains the absence of clear biomarkers associated with protection and safety. Recent studies in evaluation of vaccines, e.g., influenza and yellow fever vaccines, using systems biology tools demonstrated the power of such strategies in understanding the immunological mechanisms that underpin a protective phenotype. Applying similar tools in isolated human tissues such as PBMCs from healthy individuals infected with live attenuated parasites such as LdCen−/− in vitro followed by human microarray hybridization experiments will enable us to understand how early vaccine-induced gene expression profiles and the associated immune responses are coordinately regulated in normal

  19. Development of a Live Attenuated Bivalent Oral Vaccine Against Shigella sonnei Shigellosis and Typhoid Fever.

    Science.gov (United States)

    Wu, Yun; Chakravarty, Sumana; Li, Minglin; Wai, Tint T; Hoffman, Stephen L; Sim, B Kim Lee

    2017-01-15

    Shigella sonnei and Salmonella Typhi cause significant morbidity and mortality. We exploited the safety record of the oral, attenuated S. Typhi vaccine (Ty21a) by using it as a vector to develop a bivalent oral vaccine to protect against S. sonnei shigellosis and typhoid fever. We recombineered the S. sonnei form I O-antigen gene cluster into the Ty21a chromosome to create Ty21a-Ss, which stably expresses S. sonnei form I O antigen. To enhance survivability in the acid environment of the stomach, we created an acid-resistant strain, Ty21a-AR-Ss, by inserting Shigella glutaminase-glutamate decarboxylase systems coexpressed with S. sonnei form I O-antigen gene. Mice immunized intranasally with Ty21a-AR-Ss produced antibodies against S. sonnei and S. Typhi, and survived lethal intranasal S. sonnei challenge. This paves the way for proposed good manufacturing practices manufacture and clinical trials intended to test the clinical effectiveness of Ty21a-AR-Ss in protecting against S. sonnei shigellosis and typhoid fever, as compared with the current Ty21a vaccine. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  20. The live attenuated chimeric vaccine rWN/DEN4Δ30 is well-tolerated and immunogenic in healthy flavivirus-naïve adult volunteers.

    Science.gov (United States)

    Durbin, Anna P; Wright, Peter F; Cox, Amber; Kagucia, Wangeci; Elwood, Daniel; Henderson, Susan; Wanionek, Kimberli; Speicher, Jim; Whitehead, Stephen S; Pletnev, Alexander G

    2013-11-19

    WNV has become the leading vector-borne cause of meningoencephalitis in the United States. Although the majority of WNV infections result in asymptomatic illness, approximately 20% of infections result in West Nile fever and 1% in West Nile neuroinvasive disease (WNND), which causes encephalitis, meningitis, or flaccid paralysis. The elderly are at particular risk for WNND, with more than half the cases occurring in persons older than sixty years of age. There is no licensed treatment for WNND, nor is there any licensed vaccine for humans for the prevention of WNV infection. The Laboratory of Infectious Diseases at the National Institutes of Health has developed a recombinant live attenuated WNV vaccine based on chimerization of the wild-type WNV NY99 genome with that of the live attenuated DENV-4 candidate vaccine rDEN4Δ30. The genes encoding the prM and envelope proteins of DENV-4 were replaced with those of WNV NY99 and the resultant virus was designated rWN/DEN4Δ30. The vaccine was evaluated in healthy flavivirus-naïve adult volunteers age 18-50 years in two separate studies, both of which are reported here. The first study evaluated 10³ or 10⁴ PFU of the vaccine given as a single dose; the second study evaluated 10⁵ PFU of the vaccine given as two doses 6 months apart. The vaccine was well-tolerated and immunogenic at all three doses, inducing seroconversion to WNV NY99 in 74% (10³ PFU), 75% (10⁴ PFU), and 55% (10⁵ PFU) of subjects after a single dose. A second 10⁵ PFU dose of rWN/DEN4Δ30 given 6 months after the first dose increased the seroconversion rate 89%. Based on the encouraging results from these studies, further evaluation of the candidate vaccine in adults older than 50 years of age is planned. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Evaluation of live attenuated S79 mumps vaccine effectiveness in mumps outbreaks: a matched case-control study.

    Science.gov (United States)

    Fu, Chuan-xi; Nie, Jun; Liang, Jian-hua; Wang, Ming

    2009-02-05

    Mumps virus infection is a potentially serious viral infection of childhood and early adulthood. In China, live attenuated S(79) mumps vaccine has been licensed for pediatric use since 1990. The objective of this study was to determine the effectiveness of live attenuated S(79) mumps vaccine against clinical mumps in outbreaks. Cases were selected from mumps outbreaks in schools in Guangzhou between 2004 and 2005. Each case was matched by gender, age and classroom. Vaccination information was obtained from Children's EPI Administrative Computerized System. Vaccine effectiveness (VE) was calculated for 1 or 2 doses of S(79) vaccine with 95% confidence intervals (CI). One hundred and ninety-four cases and 194 controls were enrolled into the study. VE of the S(79) mumps vaccine for 1 dose versus 0 confer protection 80.4% (95% CI, 60.0%-90.4%) and VEs against mumps in outbreaks for 1 dose of mumps vaccine are similar among those children aged 4-9 years and aged over 10 years old. The live attenuated S(79) mumps vaccine can be effective in preventing clinical mumps outbreaks.

  2. Live Attenuated Pertussis Vaccine BPZE1 Protects Baboons Against Bordetella pertussis Disease and Infection

    Science.gov (United States)

    Papin, James F.; Lecher, Sophie; Debrie, Anne-Sophie; Thalen, Marcel; Solovay, Ken; Rubin, Keith; Mielcarek, Nathalie

    2017-01-01

    Abstract Evidence suggests that the resurgence of pertussis in many industrialized countries may result from the failure of current vaccines to prevent nasopharyngeal colonization by Bordetella pertussis, the principal causative agent of whooping cough. Here, we used a baboon model to test the protective potential of the novel, live attenuated pertussis vaccine candidate BPZE1. A single intranasal/intratracheal inoculation of juvenile baboons with BPZE1 resulted in transient nasopharyngeal colonization and induction of immunoglobulin G and immunoglobulin A to all antigens tested, while causing no adverse symptoms or leukocytosis. When BPZE1-vaccinated baboons were challenged with a high dose of a highly virulent B. pertussis isolate, they were fully protected against disease, whereas naive baboons developed illness (with 1 death) and leukocytosis. Total postchallenge nasopharyngeal virulent bacterial burden of vaccinated animals was substantially reduced (0.002%) compared to naive controls, providing promising evidence in nonhuman primates that BPZE1 protects against both pertussis disease and B. pertussis infection. PMID:28535276

  3. Major histocompatibility complex-linked immune response of young chickens vaccinated with an attenuated live infectious bursal disease virus vaccine followed by an infection

    DEFF Research Database (Denmark)

    Juul-Madsen, Helle; Nielsen, O.L.; Krogh-Maibom, T.

    2002-01-01

    The influence of the MHC on infectious bursal disease virus (IBDV) vaccine response in chickens was investigated in three different chicken lines containing four different MHC haplotypes. Two MHC haplotypes were present in all three lines with one haplotype (1319) shared between the lines. Line I...... further contains the BW1 haplotype isolated from a Red jungle Fowl. Line 131 further contains the B131 haplotype isolated from a meat-type chicken, Finally, Line 21 further contains the international B21 haplotype. The chickens were vaccinated with live attenuated commercial IBDV vaccine at 3 wk of age...

  4. Novel vector vaccine against Brucella abortus based on influenza A viruses expressing Brucella L7/L12 or Omp16 proteins: evaluation of protection in pregnant heifers.

    Science.gov (United States)

    Tabynov, Kaissar; Yespembetov, Bolat; Sansyzbay, Abylai

    2014-10-14

    The present study provides the first information about the protection of a novel influenza viral vector vaccine expressing the Brucella proteins ribosomal L7/L12 or Omp16 containing the adjuvant Montanide Gel01 in pregnant heifers. Immunization of pregnant heifers was conducted via the conjunctival (n=10) or subcutaneous (n=10) route using cross prime and booster vaccination schedules at an interval of 28 days. The vector vaccine was evaluated in comparison with positive control groups vaccinated with Brucella abortus S19 (n=10) or B. abortus RB51 (n=10) and a negative (PBS+Montanide Gel01; n=10) control group. Via both the conjunctival or subcutaneous route, evaluation of protectiveness against abortion, effectiveness of vaccination and index of infection (in heifers and their fetuses or calves) demonstrated the vector vaccine provided good protection against B. abortus 544 infection compared to the negative control group (PBS+Montanide Gel01) and comparable protection to commercial vaccines B. abortus S19 or B. abortus RB51. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Stabilization of Live Attenuated Influenza Vaccines by Freeze Drying, Spray Drying, and Foam Drying.

    Science.gov (United States)

    Lovalenti, Phillip M; Anderl, Jeff; Yee, Luisa; Nguyen, Van; Ghavami, Behnaz; Ohtake, Satoshi; Saxena, Atul; Voss, Thomas; Truong-Le, Vu

    2016-05-01

    The goal of this research is to develop stable formulations for live attenuated influenza vaccines (LAIV) by employing the drying methods freeze drying, spray drying, and foam drying. Formulated live attenuated Type-A H1N1 and B-strain influenza vaccines with a variety of excipient combinations were dried using one of the three drying methods. Process and storage stability at 4, 25 and 37°C of the LAIV in these formulations was monitored using a TCID50 potency assay. Their immunogenicity was also evaluated in a ferret model. The thermal stability of H1N1 vaccine was significantly enhanced through application of unique formulation combinations and drying processes. Foam dried formulations were as much as an order of magnitude more stable than either spray dried or freeze dried formulations, while exhibiting low process loss and full retention of immunogenicity. Based on long-term stability data, foam dried formulations exhibited a shelf life at 4, 25 and 37°C of >2, 1.5 years and 4.5 months, respectively. Foam dried LAIV Type-B manufactured using the same formulation and process parameters as H1N1 were imparted with a similar level of stability. Foam drying processing methods with appropriate selection of formulation components can produce an order of magnitude improvement in LAIV stability over other drying methods.

  6. A Reverse Genetics Approach for the Design of Methyltransferase-Defective Live Attenuated Avian Metapneumovirus Vaccines.

    Science.gov (United States)

    Zhang, Yu; Sun, Jing; Wei, Yongwei; Li, Jianrong

    2016-01-01

    Avian metapneumovirus (aMPV), also known as avian pneumovirus or turkey rhinotracheitis virus, is the causative agent of turkey rhinotracheitis and is associated with swollen head syndrome in chickens. aMPV belongs to the family Paramyxoviridae which includes many important human pathogens such as human respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and human parainfluenza virus type 3 (PIV3). The family also includes highly lethal emerging pathogens such as Nipah virus and Hendra virus, as well as agriculturally important viruses such as Newcastle disease virus (NDV). For many of these viruses, there is no effective vaccine. Here, we describe a reverse genetics approach to develop live attenuated aMPV vaccines by inhibiting the viral mRNA cap methyltransferase. The viral mRNA cap methyltransferase is an excellent target for the attenuation of paramyxoviruses because it plays essential roles in mRNA stability, efficient viral protein translation and innate immunity. We have described in detail the materials and methods used to generate recombinant aMPVs that lack viral mRNA cap methyltransferase activity. We have also provided methods to evaluate the genetic stability, pathogenesis, and immunogenicity of live aMPV vaccine candidates in turkeys.

  7. Development and biological properties of a new live attenuated mumps vaccine.

    Science.gov (United States)

    Saika, Shizuko; Kidokoro, Minoru; Kubonoya, Hiroko; Ito, Kozo; Ohkawa, Tokitada; Aoki, Athuko; Nagata, Noriyo; Suzuki, Kazuyoshi

    2006-01-01

    To develop a new live attenuated mumps vaccine, a wild mumps Y7 strain isolated from a patient who developed mild parotitis was treated with nitrosoguanidine and ultraviolet, followed by selection of a temperature-sensitive clone. The selected clone, Y125, showed stable temperature-sensitivity in Vero cells. Intraspinal inoculation of marmosets with the Y125 produced only minimal histopathological changes, while intracerebral inoculation of neonatal rats revealed that the Y125 did not cause hydrocephalus. Both these effects of the Y125 were similar to those of the non-neurovirulent Jeryl Lynn strain. Furthermore, subcutaneous inoculation of the Y125 induced high levels of neutralizing antibodies in all Cercopithecus monkeys examined. Although the safety and immunogenicity should be confirmed in further field trials in humans, the present results indicate that the Y125 could be a promising vaccine candidate.

  8. Preliminary development of a live attenuated canine parvovirus vaccine from an isolate of British origin.

    Science.gov (United States)

    Churchill, A E

    1987-04-04

    Canine parvovirus isolated from a case of haemorrhagic enteritis in a breeding kennel in England was passaged and cloned in cultured feline and canine cells. No significant evidence of pathogenicity was found during six serial passages of the modified virus back through young dogs. The attenuated virus was excreted by inoculated animals and spread rapidly to uninoculated animals held in contact. When high titre attenuated virus was given to the six-week-old offspring of a seropositive dam a prompt seroconversion was observed. When the attenuated virus was used as an experimental vaccine in 108 pups in an infected breeding colony a highly significant improvement was obtained in the accumulated morbidity and mortality compared with a parallel group vaccinated with modified live feline panleucopenia virus.

  9. Evaluation of a Salmonella vectored vaccine expressing Mycobacterium avium subsp. paratuberculosis antigens against challenge in a goat model.

    Directory of Open Access Journals (Sweden)

    Syed M Faisal

    Full Text Available Johnes disease (JD, caused by Mycobacterium avium subsp paratuberculosis (MAP, occurs worldwide as chronic granulomatous enteritis of domestic and wild ruminants. To develop a cost effective vaccine, in a previous study we constructed an attenuated Salmonella strain that expressed a fusion product made up of partial fragments of MAP antigens (Ag85A, Ag85B and SOD that imparted protection against challenge in a mouse model. In the current study we evaluated the differential immune response and protective efficacy of the Sal-Ag vaccine against challenge in a goat model as compared to the live attenuated vaccine MAP316F. PBMCs from goats vaccinated with Sal-Ag and challenged with MAP generated significantly lower levels of IFN-γ, following in vitro stimulation with either Antigen-mix or PPD jhonin, than PBMC from MAP316F vaccinated animals. Flow cytometric analysis showed the increase in IFN-γ correlated with a significantly higher level of proliferation of CD4, CD8 and γδT cells and an increased expression of CD25 and CD45R0 in MAP316F vaccinated animals as compared to control animals. Evaluation of a range of cytokines involved in Th1, Th2, Treg, and Th17 immune responses by quantitative PCR showed low levels of expression of Th1 (IFN-γ, IL-2, IL-12 and proinflammatory cytokines (IL-6, IL-8, IL-18, TNF-α in the Sal-Ag immunized group. Significant levels of Th2 and anti-inflammatory cytokines transcripts (IL-4, IL-10, IL-13, TGF-β were expressed but their level was low and with a pattern similar to the control group. Over all, Sal-Ag vaccine imparted partial protection that limited colonization in tissues of some animals upon challenge with wild type MAP but not to the level achieved with MAP316F. In conclusion, the data indicates that Sal-Ag vaccine induced only a low level of protective immunity that failed to limit the colonization of MAP in infected animals. Hence the Sal-Ag vaccine needs further refinement to increase its efficacy.

  10. Evaluation of a vectored equine herpesvirus type 1 (EHV-1) vaccine expressing H3 haemagglutinin in the protection of dogs against canine influenza.

    Science.gov (United States)

    Rosas, Cristina; Van de Walle, Gerlinde R; Metzger, Stephan M; Hoelzer, Karin; Dubovi, Edward J; Kim, Sung G; Parrish, Colin R; Osterrieder, Nikolaus

    2008-05-02

    In 2004, canine influenza virus (CIV) was identified as a respiratory pathogen of dogs for the first time and found to be closely related to H3N8 equine influenza virus (EIV). We generated a recombinant vectored vaccine that expresses H3 of a recent isolate of EIV using equine herpesvirus type 1 (EHV-1) as the delivery vehicle. This EHV-1 vectored vaccine exhibited robust and stable EIV H3 expression and induced a strong influenza virus-specific response in both mice and dogs upon intranasal or subcutaneous administration. Furthermore, upon challenge with the recent CIV isolate A/canine/PA/10915-07, protection of vaccinated dogs could be demonstrated by a significant reduction in clinical sings, and, more importantly, by a significant reduction in virus shedding. We concluded that the EHV-1/H3 recombinant vector can be a valuable alternative for protection of dogs against clinical disease induced by CIV and can significantly reduce virus spread.

  11. Live attenuated influenza vaccine use and safety in children and adults with asthma.

    Science.gov (United States)

    Duffy, Jonathan; Lewis, Melissa; Harrington, Theresa; Baxter, Roger; Belongia, Edward A; Jackson, Lisa A; Jacobsen, Steven J; Lee, Grace M; Naleway, Allison L; Nordin, James; Daley, Matthew F

    2017-04-01

    Live attenuated influenza vaccine (LAIV) might increase the risk of wheezing in persons with asthma or children younger than 5 years with a history of recurrent wheezing. To describe the use and assess the safety of LAIV in persons with asthma in the Vaccine Safety Datalink population. We identified persons with asthma using diagnosis codes and medication records in 7 health care organizations over 3 influenza seasons (2008-2009 through 2010-2011) and determined their influenza vaccination rates. Using the self-controlled risk interval method, we calculated the incidence rate ratio of medically attended respiratory events in the 14 days after LAIV compared with 29 to 42 days after vaccination in persons 2 through 49 years old. In our population of 6.3 million, asthma prevalence was 5.9%. Of persons with asthma, approximately 50% received any influenza vaccine but less than 1% received LAIV. The safety study included 12,354 LAIV doses (75% in children; 93% in those with intermittent or mild persistent asthma). The incidence rate ratio for inpatient and emergency department visits for lower respiratory events (including asthma exacerbation and wheezing) was 0.98 (95% confidence interval 0.63-1.51) and the incidence rate ratio for upper respiratory events was 0.94 (95% confidence interval 0.48-1.86). The risk of lower respiratory events was similar for intermittent and mild persistent asthma, across age groups, and for seasonal trivalent LAIV and 2009 H1N1 pandemic monovalent LAIV. LAIV use in asthma was mostly in persons with intermittent or mild persistent asthma. LAIV was not associated with an increased risk of medically attended respiratory adverse events. Published by Elsevier Inc.

  12. Development of live attenuated Streptococcus agalactiae as potential vaccines by selecting for resistance to sparfloxacin.

    Science.gov (United States)

    Pridgeon, Julia W; Klesius, Phillip H

    2013-05-31

    To develop attenuated bacteria as potential live vaccines, sparfloxacin was used in this study to modify 40 isolates of Streptococcus agalactiae. Majority of S. agalactiae used in this study were able to develop at least 80-fold resistance to sparfloxacin. When the virulence of the sparfloxacin-resistant S. agalactiae isolates were tested in 10-12g Nile tilapia by intraperitoneal injection at dose of 2×10(7)CFU/fish, 31 were found to be avirulent to fish. Of the 31 avirulent sparfloxacin-resistant S. agalactiae isolates, 30 provided 75-100% protection to 10-12g Nile tilapia against challenges with a virulent S. agalactiae isolate Sag 50. When the virulence of the 30 sparfloxacin-resistant S. agalactiae isolates was tested in 3-5g Nile tilapia by intraperitoneal injection at dose of 2×10(7)CFU/fish, six were found to be avirulent to 3-5g Nile tilapia. Of the six avirulent sparfloxacin-resistant S. agalactiae isolates, four provided 3-5g Nile tilapia 100% protection against challenges with homologous isolates, including Sag 97-spar isolate that was non-hemolytic. However, Sag 97-spar failed to provide broad cross-protection against challenges with heterologous isolates. When Nile tilapia was vaccinated with a polyvalent vaccine consisting of 30 sparfloxacin-resistant S. agalactiae isolates at dose of 2×10(6)CFU/fish, the polyvalent vaccine provided significant (PS. agalactiae. Taken together, our results suggest that a polyvalent vaccine consisting of various strains of S. agalactiae might be essential to provide broader protection to Nile tilapia against infections caused by S. agalactiae. Published by Elsevier Ltd.

  13. Full-length genome sequence analysis of an avian leukosis virus subgroup J (ALV-J) as contaminant in live poultry vaccine: The commercial live vaccines might be a potential route for ALV-J transmission.

    Science.gov (United States)

    Wang, P; Lin, L; Li, H; Shi, M; Gu, Z; Wei, P

    2018-02-25

    One avian leukosis virus subgroup J (ALV-J) strain was isolated from 67 commercial live poultry vaccines produced by various manufacturers during 2013-2016 in China. The complete genomes of the isolate were sequenced and it was found that the genes gag and pol of the strain were relatively conservative, while the gp85 gene of the strain GX14YYA1 had the highest similarities with a field strain GX14ZS14, which was isolated from the chickens of a farm that had once used the same vaccine as the one found to be contaminated with the GX14YYA1. This is the first report of ALV-J contaminant in live poultry vaccine in China. Our finding demonstrates that vaccination of the commercial live vaccines might be a potential new route for ALV-J transmission in chickens and highlights the need for more extensive monitoring of the commercial live vaccines in China. © 2018 Blackwell Verlag GmbH.

  14. malERA: An updated research agenda for diagnostics, drugs, vaccines, and vector control in malaria elimination and eradication.

    Science.gov (United States)

    2017-11-01

    Since the turn of the century, a remarkable expansion has been achieved in the range and effectiveness of products and strategies available to prevent, treat, and control malaria, including advances in diagnostics, drugs, vaccines, and vector control. These advances have once again put malaria elimination on the agenda. However, it is clear that even with the means available today, malaria control and elimination pose a formidable challenge in many settings. Thus, currently available resources must be used more effectively, and new products and approaches likely to achieve these goals must be developed. This paper considers tools (both those available and others that may be required) to achieve and maintain malaria elimination. New diagnostics are needed to direct treatment and detect transmission potential; new drugs and vaccines to overcome existing resistance and protect against clinical and severe disease, as well as block transmission and prevent relapses; and new vector control measures to overcome insecticide resistance and more powerfully interrupt transmission. It is also essential that strategies for combining new and existing approaches are developed for different settings to maximise their longevity and effectiveness in areas with continuing transmission and receptivity. For areas where local elimination has been recently achieved, understanding which measures are needed to maintain elimination is necessary to prevent rebound and the reestablishment of transmission. This becomes increasingly important as more countries move towards elimination.

  15. Safety and Immunogenicity of a Recombinant Adenovirus Serotype 35-Vectored HIV-1 Vaccine in Adenovirus Serotype 5 Seronegative and Seropositive Individuals.

    Science.gov (United States)

    Fuchs, Jonathan D; Bart, Pierre-Alexandre; Frahm, Nicole; Morgan, Cecilia; Gilbert, Peter B; Kochar, Nidhi; DeRosa, Stephen C; Tomaras, Georgia D; Wagner, Theresa M; Baden, Lindsey R; Koblin, Beryl A; Rouphael, Nadine G; Kalams, Spyros A; Keefer, Michael C; Goepfert, Paul A; Sobieszczyk, Magdalena E; Mayer, Kenneth H; Swann, Edith; Liao, Hua-Xin; Haynes, Barton F; Graham, Barney S; McElrath, M Juliana

    2015-05-01

    Recombinant adenovirus serotype 5 (rAd5)-vectored HIV-1 vaccines have not prevented HIV-1 infection or disease and pre-existing Ad5 neutralizing antibodies may limit the clinical utility of Ad5 vectors globally. Using a rare Ad serotype vector, such as Ad35, may circumvent these issues, but there are few data on the safety and immunogenicity of rAd35 directly compared to rAd5 following human vaccination. HVTN 077 randomized 192 healthy, HIV-uninfected participants into one of four HIV-1 vaccine/placebo groups: rAd35/rAd5, DNA/rAd5, and DNA/rAd35 in Ad5-seronegative persons; and DNA/rAd35 in Ad5-seropositive persons. All vaccines encoded the HIV-1 EnvA antigen. Antibody and T-cell responses were measured 4 weeks post boost immunization. All vaccines were generally well tolerated and similarly immunogenic. As compared to rAd5, rAd35 was equally potent in boosting HIV-1-specific humoral and cellular immunity and responses were not significantly attenuated in those with baseline Ad5 seropositivity. Like DNA, rAd35 efficiently primed rAd5 boosting. All vaccine regimens tested elicited cross-clade antibody responses, including Env V1/V2-specific IgG responses. Vaccine antigen delivery by rAd35 is well-tolerated and immunogenic as a prime to rAd5 immunization and as a boost to prior DNA immunization with the homologous insert. Further development of rAd35-vectored prime-boost vaccine regimens is warranted.

  16. Revaccination of Guinea Pigs With the Live Attenuated Mycobacterium tuberculosis Vaccine MTBVAC Improves BCG's Protection Against Tuberculosis.

    Science.gov (United States)

    Clark, Simon; Lanni, Faye; Marinova, Dessislava; Rayner, Emma; Martin, Carlos; Williams, Ann

    2017-09-01

    The need for an effective vaccine against human tuberculosis has driven the development of different candidates and vaccination strategies. Novel live attenuated vaccines are being developed that promise greater safety and efficacy than BCG against tuberculosis. We combined BCG with the vaccine MTBVAC to evaluate whether the efficacy of either vaccine would be affected upon revaccination. In a well-established guinea pig model of aerosol infection with Mycobacterium tuberculosis, BCG and MTBVAC delivered via various prime-boost combinations or alone were compared. Efficacy was determined by a reduction in bacterial load 4 weeks after challenge. Efficacy data suggests MTBVAC-associated immunity is longer lasting than that of BCG when given as a single dose. Long and short intervals between BCG prime and MTBVAC boost resulted in improved efficacy in lungs, compared with BCG given alone. A shorter interval between MTBVAC prime and BCG boost resulted in improved efficacy in lungs, compared with BCG given alone. A longer interval resulted in protection equivalent to that of BCG given alone. These data indicate that, rather than boosting the waning efficacy of BCG, a vaccination schedule involving a combination of the 2 vaccines yielded stronger immunity to M. tuberculosis infection. This work supports development of MTBVAC use as a revaccination strategy to improve on the effects of BCG in vaccinated people living in tuberculosis-endemic countries. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  17. Live attenuated Francisella novicida vaccine protects against Francisella tularensis pulmonary challenge in rats and non-human primates.

    Directory of Open Access Journals (Sweden)

    Ping Chu

    2014-10-01

    Full Text Available Francisella tularensis causes the disease tularemia. Human pulmonary exposure to the most virulent form, F. tularensis subsp. tularensis (Ftt, leads to high morbidity and mortality, resulting in this bacterium being classified as a potential biothreat agent. However, a closely-related species, F. novicida, is avirulent in healthy humans. No tularemia vaccine is currently approved for human use. We demonstrate that a single dose vaccine of a live attenuated F. novicida strain (Fn iglD protects against subsequent pulmonary challenge with Ftt using two different animal models, Fischer 344 rats and cynomolgus macaques (NHP. The Fn iglD vaccine showed protective efficacy in rats, as did a Ftt iglD vaccine, suggesting no disadvantage to utilizing the low human virulent Francisella species to induce protective immunity. Comparison of specific antibody profiles in vaccinated rat and NHP sera by proteome array identified a core set of immunodominant antigens in vaccinated animals. This is the first report of a defined live attenuated vaccine that demonstrates efficacy against pulmonary tularemia in a NHP, and indicates that the low human virulence F. novicida functions as an effective tularemia vaccine platform.

  18. The Long-Term Safety, Public Health Impact, and Cost-Effectiveness of Routine Vaccination with a Recombinant, Live-Attenuated Dengue Vaccine (Dengvaxia): A Model Comparison Study.

    Science.gov (United States)

    Flasche, Stefan; Jit, Mark; Rodríguez-Barraquer, Isabel; Coudeville, Laurent; Recker, Mario; Koelle, Katia; Milne, George; Hladish, Thomas J; Perkins, T Alex; Cummings, Derek A T; Dorigatti, Ilaria; Laydon, Daniel J; España, Guido; Kelso, Joel; Longini, Ira; Lourenco, Jose; Pearson, Carl A B; Reiner, Robert C; Mier-Y-Terán-Romero, Luis; Vannice, Kirsten; Ferguson, Neil

    2016-11-01

    Large Phase III trials across Asia and Latin America have recently demonstrated the efficacy of a recombinant, live-attenuated dengue vaccine (Dengvaxia) over the first 25 mo following vaccination. Subsequent data collected in the longer-term follow-up phase, however, have raised concerns about a potential increase in hospitalization risk of subsequent dengue infections, in particular among young, dengue-naïve vaccinees. We here report predictions from eight independent modelling groups on the long-term safety, public health impact, and cost-effectiveness of routine vaccination with Dengvaxia in a range of transmission settings, as characterised by seroprevalence levels among 9-y-olds (SP9). These predictions were conducted for the World Health Organization to inform their recommendations on optimal use of this vaccine. The models adopted, with small variations, a parsimonious vaccine mode of action that was able to reproduce quantitative features of the observed trial data. The adopted mode of action assumed that vaccination, similarly to natural infection, induces transient, heterologous protection and, further, establishes a long-lasting immunogenic memory, which determines disease severity of subsequent infections. The default vaccination policy considered was routine vaccination of 9-y-old children in a three-dose schedule at 80% coverage. The outcomes examined were the impact of vaccination on infections, symptomatic dengue, hospitalised dengue, deaths, and cost-effectiveness over a 30-y postvaccination period. Case definitions were chosen in accordance with the Phase III trials. All models predicted that in settings with moderate to high dengue endemicity (SP9 ≥ 50%), the default vaccination policy would reduce the burden of dengue disease for the population by 6%-25% (all simulations: -3%-34%) and in high-transmission settings (SP9 ≥ 70%) by 13%-25% (all simulations: 10%- 34%). These endemicity levels are representative of the participating sites in

  19. The Long-Term Safety, Public Health Impact, and Cost-Effectiveness of Routine Vaccination with a Recombinant, Live-Attenuated Dengue Vaccine (Dengvaxia: A Model Comparison Study.

    Directory of Open Access Journals (Sweden)

    Stefan Flasche

    2016-11-01

    Full Text Available Large Phase III trials across Asia and Latin America have recently demonstrated the efficacy of a recombinant, live-attenuated dengue vaccine (Dengvaxia over the first 25 mo following vaccination. Subsequent data collected in the longer-term follow-up phase, however, have raised concerns about a potential increase in hospitalization risk of subsequent dengue infections, in particular among young, dengue-naïve vaccinees. We here report predictions from eight independent modelling groups on the long-term safety, public health impact, and cost-effectiveness of routine vaccination with Dengvaxia in a range of transmission settings, as characterised by seroprevalence levels among 9-y-olds (SP9. These predictions were conducted for the World Health Organization to inform their recommendations on optimal use of this vaccine.The models adopted, with small variations, a parsimonious vaccine mode of action that was able to reproduce quantitative features of the observed trial data. The adopted mode of action assumed that vaccination, similarly to natural infection, induces transient, heterologous protection and, further, establishes a long-lasting immunogenic memory, which determines disease severity of subsequent infections. The default vaccination policy considered was routine vaccination of 9-y-old children in a three-dose schedule at 80% coverage. The outcomes examined were the impact of vaccination on infections, symptomatic dengue, hospitalised dengue, deaths, and cost-effectiveness over a 30-y postvaccination period. Case definitions were chosen in accordance with the Phase III trials. All models predicted that in settings with moderate to high dengue endemicity (SP9 ≥ 50%, the default vaccination policy would reduce the burden of dengue disease for the population by 6%-25% (all simulations: -3%-34% and in high-transmission settings (SP9 ≥ 70% by 13%-25% (all simulations: 10%- 34%. These endemicity levels are representative of the

  20. Live recombinant Salmonella Typhi vaccines constructed to investigate the role of rpoS in eliciting immunity to a heterologous antigen.

    Directory of Open Access Journals (Sweden)

    Huoying Shi

    2010-06-01

    Full Text Available We hypothesized that the immunogenicity of live Salmonella enterica serovar Typhi vaccines expressing heterologous antigens depends, at least in part, on its rpoS status. As part of our project to develop a recombinant attenuated S. Typhi vaccine (RASTyV to prevent pneumococcal diseases in infants and children, we constructed three RASTyV strains synthesizing the Streptococcus pneumoniae surface protein PspA to test this hypothesis. Each vector strain carried ten engineered mutations designed to optimize safety and immunogenicity. Two S. Typhi vector strains (chi9639 and chi9640 were derived from the rpoS mutant strain Ty2 and one (chi9633 from the RpoS(+ strain ISP1820. In chi9640, the nonfunctional rpoS gene was replaced with the functional rpoS gene from ISP1820. Plasmid pYA4088, encoding a secreted form of PspA, was moved into the three vector strains. The resulting RASTyV strains were evaluated for safety in vitro and for immunogenicity in mice. All three RASTyV strains were similar to the live attenuated typhoid vaccine Ty21a in their ability to survive in human blood and human monocytes. They were more sensitive to complement and were less able to survive and persist in sewage and surface water than their wild-type counterparts. Adult mice intranasally immunized with any of the RASTyV strains developed immune responses against PspA and Salmonella antigens. The RpoS(+ vaccines induced a balanced Th1/Th2 immune response while the RpoS(- strain chi9639(pYA4088 induced a strong Th2 immune response. Immunization with any RASTyV provided protection against S. pneumoniae challenge; the RpoS(+ strain chi9640(pYA4088 provided significantly greater protection than the ISP1820 derivative, chi9633(pYA4088. In the pre-clinical setting, these strains exhibited a desirable balance between safety and immunogenicity and are currently being evaluated in a Phase 1 clinical trial to determine which of the three RASTyVs has the optimal safety and

  1. Evaluation of a vectored equine herpesvirus type 1 (EHV-1) vaccine expressing H3 haemagglutinin in the protection of dogs against canine influenza

    OpenAIRE

    Rosas, Cristina; Van de Walle, Gerlinde R.; Metzger, Stephan M.; Hoelzer, Karin; Dubovi, Edward J.; Kim, Sung G.; Parrish, Colin R.; Osterrieder, Nikolaus

    2008-01-01

    In 2004, canine influenza virus (CIV) was identified as a respiratory pathogen of dogs for the first time and is closely related to H3N8 equine influenza virus (EIV). We generated a recombinant vectored vaccine that expresses H3 of a recent isolate of EIV using equine herpesvirus type 1 (EHV-1) as the delivery vehicle. This EHV-1 vectored vaccine exhibited robust and stable EIV H3 expression and induced a strong influenza virus-specific response in both mice and dogs upon intranasal or subcut...

  2. Hatchery Vaccination Against Poultry Viral Diseases: Potential Mechanisms and Limitations.

    Science.gov (United States)

    Abdul-Cader, Mohamed Sarjoon; Palomino-Tapia, Victor; Amarasinghe, Aruna; Ahmed-Hassan, Hanaa; De Silva Senapathi, Upasama; Abdul-Careem, Mohamed Faizal

    Commercial broiler and layer chickens are heavily vaccinated against economically important viral diseases with a view of preventing morbidity, mortality, and production impacts encountered during short production cycles. Hatchery vaccination is performed through in ovo embryo vaccination prehatch or spray and subcutaneous vaccinations performed at the day of hatch before the day-old chickens are being placed in barns with potentially contaminated environments. Commercially, multiple vaccines (e.g., live, live attenuated, and viral vectored vaccines) are available to administer through these routes within a short period (embryo day 18 prehatch to day 1 posthatch). Although the ability to mount immune response, especially the adaptive immune response, is not optimal around the hatch, it is possible that the efficacy of these vaccines depends partly on innate host responses elicited in response to replicating vaccine viruses. This review focuses on the current knowledge of hatchery vaccination in poultry and potential mechanisms of hatchery vaccine-mediated protective responses and limitations.

  3. Utility of two modified-live virus canine distemper vaccines in wild-caught fishers (Martes pennanti).

    Science.gov (United States)

    Peper, Steven T; Peper, Randall L; Mitcheltree, Denise H; Kollias, George V; Brooks, Robert P; Stevens, Sadie S; Serfass, Thomas L

    2016-12-01

    Canine distemper virus (CDV) infects families in the order Carnivora. As a preventive measure, vaccinations against CDV are frequently given to mustelids in captive environments. Our objectives were to compare the utility between two modified-live virus canine distemper vaccines (MLV CDV's), Fervac-D® (no longer manufactured) and Galaxy-D® (now manufactured by MSD Animal Health as part of a multivalent vaccine), in developing an immune response in wild-caught fishers. The Pennsylvania Fisher Reintroduction Project (PFRP) used 14 wild-caught fishers during one year of the project to evaluate the utility of vaccinations against CDV as part of any reintroduction project. Fishers were injected subcutaneously in the nape of the neck with their designated vaccine. Fervac-D® did not effectively stimulate development of a serologic antibody response, whereas Galaxy-D® had adequate seroconversion or rise of titer levels to suggest that the general use of MLV CDV may be suitable in fishers pending further studies. We recommend that future studies be conducted, evaluating the use of currently produced vaccines in fishers. Future research should also focus on the length of days required between administration of primary and booster vaccines to achieve sufficient immune response. If only primary doses are required, then hard-release reintroduction projects for fishers could be recommended. If primary and booster vaccines are required then soft-release reintroduction projects should be recommended that include captive management periods, allowing for appropriate vaccination intervals needed to maximize the probability of protection against CDV.

  4. Transplacental rotavirus IgG interferes with immune response to live oral rotavirus vaccine ORV-116E in Indian infants.

    Science.gov (United States)

    Appaiahgari, Mohan Babu; Glass, Roger; Singh, Shakti; Taneja, Sunita; Rongsen-Chandola, Temsunaro; Bhandari, Nita; Mishra, Sukhdev; Vrati, Sudhanshu

    2014-02-03

    The lower immune response and efficacy of live oral rotavirus (RV) vaccines tested in developing countries may be due in part to high levels of pre-existing RV antibodies transferred to the infant from mother via the placenta. The candidate RV vaccine strain 116E was isolated from a newborn indicating that it might grow well even in the presence of this transplacental rotavirus antibody. Since the immune response to this vaccine among infants in the Indian subcontinent has been greater than that of the commercially licensed vaccines, we questioned whether this might be due to the ability of RV 116E to grow well in infants despite the presence of maternal RV antibody. To this end, we tested pre-immunization sera from Indian infants enrolled in a phase Ia/IIb trial of candidate RV vaccine ORV-116E for transplacental RV IgG to see whether it affected the immune responses and seroconversion to the vaccine. We found that the high titers of transplacental RV IgG diminished the immune responses of infants to ORV-116E vaccine. However, the vaccine was able to overcome the inhibitory effect of this RV IgG in a dose-dependent manner. This report clearly demonstrates the interference of maternal antibody on RV vaccine immunogenicity in infants in a field study as well as the ability of ORV-116E to overcome this interference when used at a higher dose. Copyright © 2013. Published by Elsevier Ltd.

  5. A goat poxvirus-vectored peste-des-petits-ruminants vaccine induces long-lasting neutralization antibody to high levels in goats and sheep.

    Science.gov (United States)

    Chen, Weiye; Hu, Sen; Qu, Linmao; Hu, Qianqian; Zhang, Qian; Zhi, Haibing; Huang, Kehe; Bu, Zhigao

    2010-07-05

    Recombinant capripoxvirus (CPV) is a promising candidate differentiating infected from vaccinated animals (DIVA) vaccine against peste-des-petits-ruminants (PPR). In order for recombinant CPV to be successfully used in the field, there should exist dependable indicators for quality control of vaccine products, surveillance and vaccination evaluation. Viral neutralization antibody (VNA) is correlated to protection against PPR and is a technically feasible indicator for this purpose. The immunogenicity of this vectored vaccine in goats and sheep, however, has not been fully evaluated. In this study, we generated two recombinant CPV viruses, rCPV-PPRVH and rCPV-PPRVF, that express PPR virus (PPRV) glycoproteins H and F, respectively. Vaccination studies with different dosages of recombinant viruses showed that rCPV-PPRVH was a more potent inducer of PPRV VNA than rCPV-PPRVF. One dose of rCPV-PPRVH was enough to seroconvert 80% of immunized sheep. A second dose induced significantly higher PPRV VNA titers. There was no significant difference in PPRV VNA responses between goats and sheep. Subcutaneous inoculation also induced a significant PPRV VNA response. PPRV VNA could be detected for over 6 months in more than 80% of vaccinated goats and sheep. Boost vaccination at 6-month intervals induced significant re-boost efficacy of PPRV VNA in goats and sheep. More over, two doses of rCPV-PPRVH could completely overcome the interference caused by pre-existing immunity to the CPV vaccine backbone in animals. Vaccination with rCPV-PPRVH also protected goats from virulent CPV challenge. Our results demonstrate that VNA can serve as a dependent indicator for effective vaccination and immune protection of animals in the field. The recombinant CPV vaccine used in our studies could be a practical and useful candidate DIVA vaccine in countries where PPR newly emerges or where stamp-out plans are yet to be implemented. Copyright 2010 Elsevier Ltd. All rights reserved.

  6. Hexon-modified recombinant E1-deleted adenoviral vectors as bivalent vaccine carriers for Coxsackievirus A16 and Enterovirus 71.

    Science.gov (United States)

    Zhang, Chao; Yang, Yong; Chi, Yudan; Yin, Jieyun; Yan, Lijun; Ku, Zhiqiang; Liu, Qingwei; Huang, Zhong; Zhou, Dongming

    2015-09-22

    Hand, foot and mouth disease (HFMD) is a major public health concern in Asia; more efficient vaccines against HFMD are urgently required. Adenoviral (Ad) capsids have been used widely for the presentation of foreign antigens to induce specific immune responses in the host. Here, we describe a novel bivalent vaccine for HFMD based on the hexon-modified, E1-deleted chimpanzee adenovirus serotype 68 (AdC68). The novel vaccine candidate was generated by incorporating the neutralising epitope of Coxsackievirus A16 (CA16), PEP71, into hypervariable region 1 (HVR1), and a shortened neutralising epitope of Enterovirus 71 (EV71), sSP70, into HVR2 of the AdC68 hexon. In order to enhance the immunogenicity of EV71, VP1 of EV71 was cloned into the E1-region of the AdC68 vectors. The results demonstrated that these two epitopes were well presented on the virion surface and had high affinity towards specific antibodies, and VP1 of EV71 was also significantly expressed. In pre-clinical mouse models, the hexon-modified AdC68 elicited neutralising antibodies against both CA16 and EV71, which conferred protection to suckling mice against a lethal challenge of CA16 and EV71. In summary, this study demonstrates that the hexon-modified AdC68 may represent a promising bivalent vaccine carrier against EV71 and CA16 and an epitope-display platform for other pathogens. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Biodistribution and safety of a live attenuated tetravalent dengue vaccine in the cynomolgus monkey.

    Science.gov (United States)

    Ravel, Guillaume; Mantel, Nathalie; Silvano, Jeremy; Rogue, Alexandra; Guy, Bruno; Jackson, Nicholas; Burdin, Nicolas

    2017-10-13

    The first licensed dengue vaccine is a recombinant, live, attenuated, tetravalent dengue virus vaccine (CYD-TDV; Sanofi Pasteur). This study assessed the biodistribution, shedding, and toxicity of CYD-TDV in a non-human primate model as part of the nonclinical safety assessment program for the vaccine. Cynomolgus monkeys were given one subcutaneous injection of either one human dose (5log 10 CCID 50 /serotype) of CYD-TDV or saline control. Study endpoints included clinical observations, body temperature, body weight, food consumption, clinical pathology, immunogenicity, and post-mortem examinations including histopathology. Viral load, distribution, persistence, and shedding in tissues and body fluids were evaluated by quantitative reverse transcriptase polymerase chain reaction. The subcutaneous administration of CYD-TDV was well tolerated. There were no toxicological findings other than expected minor local reactions at the injection site. A transient low level of CYD-TDV viral RNA was detected in blood and the viral genome was identified primarily at the injection site and in the draining lymph nodes following immunization. These results, together with other data from repeat-dose toxicity and neurovirulence studies, confirm the absence of toxicological concern with CYD-TDV and corroborate clinical study observations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Post-marketing safety surveillance for inactivated and live-attenuated Japanese encephalitis vaccines in China, 2008-2013.

    Science.gov (United States)

    Wu, Wendi; Liu, Dawei; Li, Keli; Nuorti, J Pekka; Nohynek, Hanna M; Xu, Disha; Ye, Jiakai; Zheng, Jingshan; Wang, Huaqing

    2017-06-22

    Two types of Japanese encephalitis (JE) vaccines, inactivated JE vaccine (JE-I) and live-attenuated JE vaccine (JE-L), are available and used in China. In particular, one JE-L, produced by a domestic manufacturer in China, was prequalified by WHO in 2013. We assessed the safety of JE vaccines in China during 2008-2013 using the Chinese National Adverse Events Following Immunization Information System (CNAEFIS) data. We retrieved AEFI reporting data about JE vaccines from CNAEFIS, 2008-2013, examined demographic characteristics of AEFI cases, and used administrative data on vaccine doses as denominator to calculate and compare crude reporting rates. We also used disproportionality reporting analysis between JE-I and JE-L to assess potential safety signals. A total of 34,879 AEFIs related with JE-I and JE-L were reported, with a ratio of male to female as 1.3:1; 361 (1.0%) cases were classified as serious. JE vaccines were administered concurrently with one or more other vaccines in 13,592 (39.0%) of cases. The overall AEFI reporting rates were 214.4 per million vaccination doses for JE-L and 176.9 for JE-I (rate ratio [RR]: 1.2, 95% confidence interval [CI]: 1.1-1.3) in 2010-2013. Febrile convulsions (FC) following JE-I was found as a signal of disproportionate reporting (SDR). However, there was no significant difference between the reporting rates of FC of JE-I and JE-L (0.3 per million vaccination doses for JE-L, 0.4 for JE-I, p=0.05). While our analysis did not find apparent safety concern of JE vaccines in China, further study should consider JE-I vaccines and febrile convulsion, and taking more sensitive methods to detect signals. Copyright © 2017. Published by Elsevier Ltd.

  9. Interferon alpha inhibits replication of a live-attenuated porcine reproductive and respiratory syndrome virus vaccine preventing development of an adaptive immune response in swine.

    Science.gov (United States)

    Brockmeier, Susan L; Loving, Crystal L; Eberle, Kirsten C; Hau, Samantha J; Buckley, Alexandra; Van Geelen, Albert; Montiel, Nestor A; Nicholson, Tracy; Lager, Kelly M

    2017-12-01

    Type I interferons, such as interferon alpha (IFN-α), contribute to innate antiviral immunity by promoting production of antiviral mediators and are also involved in promoting an adaptive immune response. Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most devastating and costly viruses to the swine industry world-wide and has been shown to induce a meager IFN-α response. Previously we administered porcine IFN-α using a replication-defective adenovirus vector (Ad5-IFN-α) at the time of challenge with virulent PRRSV and demonstrated an increase in the number of virus-specific IFNγ secreting cells, indicating that the presence of IFN-α at the time of infection can alter the adaptive immune responses to PRRSV. In the current experiment, we explored the use of IFN-α as an adjuvant administered with live-attenuated PRRSV vaccine as a method to enhance immune response to the vaccine. Unlike the previous studies with fully virulent virus, one injection of the Ad5-IFN-α abolished replication of the vaccine virus and as a result there was no detectible adaptive immune response. Although IFN-α did not have the desired adjuvant effect, the results further highlight the use of IFN-α as a treatment for PRRSV infection. Published by Elsevier B.V.

  10. Cost of production of live attenuated dengue vaccines: a case study of the Instituto Butantan, Sao Paulo, Brazil.

    Science.gov (United States)

    Mahoney, R T; Francis, D P; Frazatti-Gallina, N M; Precioso, A R; Raw, I; Watler, P; Whitehead, P; Whitehead, S S

    2012-07-06

    A vaccine to prevent dengue disease is urgently needed. Fortunately, a few tetravalent candidate vaccines are in the later stages of development and show promise. But, if the cost of these candidates is too high, their beneficial potential will not be realized. The price of a vaccine is one of the most important factors affecting its ultimate application in developing countries. In recent years, new vaccines such as those for human papilloma virus and pneumococcal disease (conjugate vaccine) have been introduced with prices in developed countries exceeding $50 per dose. These prices are above the level affordable by developing countries. In contrast, other vaccines such as those against Japanese encephalitis (SA14-14-2 strain vaccine) and meningitis type A have prices in developing countries below one dollar per dose, and it is expected that their introduction and use will proceed more rapidly. Because dengue disease is caused by four related viruses, vaccines must be able to protect against all four. Although there are several live attenuated dengue vaccine candidates under clinical evaluation, there remains uncertainty about the cost of production of these tetravalent vaccines, and this uncertainty is an impediment to rapid progress in planning for the introduction and distribution of dengue vaccines once they are licensed. We have undertaken a detailed economic analysis, using standard industrial methodologies and applying generally accepted accounting practices, of the cost of production of a live attenuated vaccine, originally developed at the US National Institutes of Health (National Institute of Allergy and Infectious Diseases), to be produced at the Instituto Butantan in Sao Paulo, Brazil. We determined direct costs of materials, direct costs of personnel and labor, indirect costs, and depreciation. These were analyzed assuming a steady-state production of 60 million doses per year. Although this study does not seek to compute the price of the final

  11. Children who have received no routine polio vaccines in Nigeria: Who are they and where do they live?

    Science.gov (United States)

    Uthman, Olalekan A; Adedokun, Sulaimon T; Olukade, Tawa; Watson, Samuel; Adetokunboh, Olatunji; Adeniran, Adeyinka; Oyetoyan, Solomon A; Gidado, Saheed; Lawoko, Stephen; Wiysonge, Charles S

    2017-09-02

    Nigeria has made remarkable progress against polio, but 2 wild polio virus cases were reported in August 2016; putting an end to 2 y without reported cases. We examined the extent of geographical disparities in childhren not vaccinated against polio and examined individual- and community-level predictors of non-vaccination in Nigeria. We applied multilevel logistic regression models to the recent Nigeria Demographic and Health Survey. The percentage of children not routinely vaccinated against polio in Nigeria varied greatly and clustered geographically, mainly in north-eastern states, with a great risk of spread of transmission within these states and potential exportation to neighboring states and countries. Only about one-third had received all recommended 4 routine oral polio vaccine doses. Non-vaccinated children tended to have a mother who had no formal education and who was currently not working, live in poorer households and were from neighborhoods with higher maternal illiteracy rates.

  12. Protective efficacy of a live attenuated anti-coccidial vaccine administered to 1-day-old chickens.

    Science.gov (United States)

    Crouch, C F; Andrews, S J; Ward, R G; Francis, M J

    2003-06-01

    The efficacy of a live attenuated anti-coccidial vaccine, Paracox-5, administered to 1-day-old chicks was investigated by assessing protection against changes in weight gain following virulent challenge. Vaccinated birds were challenged independently 28 days later with each of the component species (Eimeria acervulina, Eimeria maxima, Eimeria mitis or Eimeria tenella), and protection was demonstrated against associated reduction in weight gain and lesion formation. In addition, an improvement in bird performance, in terms of feed conversion ratio, was also observed following vaccination. Furthermore, under conditions designed to more closely mimic those in the field and using hatchery spray administration, protection against a mixed virulent challenge introduced by 'seeder birds' was demonstrated evenly across a flock of broiler birds within 21 days after vaccination. These data demonstrate that Paracox-5 vaccine will protect broiler chickens against the adverse effects on performance induced by Eimeria spp.

  13. Polymeric nanoparticles: potent vectors for vaccine delivery targeting cancer and infectious diseases.

    Science.gov (United States)

    Bolhassani, Azam; Javanzad, Shabnam; Saleh, Tayebeh; Hashemi, Mehrdad; Aghasadeghi, Mohammad Reza; Sadat, Seyed Mehdi

    2014-01-01

    Nanocarriers with various compositions and biological properties have been extensively applied for in vitro/in vivo drug and gene delivery. The family of nanocarriers includes polymeric nanoparticles, lipid-based carriers (liposomes/micelles), dendrimers, carbon nanotubes, and gold nanoparticles (nanoshells/nanocages). Among different delivery systems, polymeric carriers have several properties such as: easy to synthesize, inexpensive, biocompatible, biodegradable, non-immunogenic, non-toxic, and water soluble. In addition, cationic polymers seem to produce more stable complexes led to a more protection during cellular trafficking than cationic lipids. Nanoparticles often show significant adjuvant effects in vaccine delivery since they may be easily taken up by antigen presenting cells (APCs). Natural polymers such as polysaccharides and synthetic polymers have demonstrated great potential to form vaccine nanoparticles. The development of new adjuvants or delivery systems for DNA and protein immunization is an expanding research field. This review describes polymeric carriers especially PLGA, chitosan, and PEI as vaccine delivery systems.

  14. Activation of cross-reactive mucosal T and B cell responses in human nasopharynx-associated lymphoid tissue in vitro by Modified Vaccinia Ankara-vectored influenza vaccines.

    Science.gov (United States)

    Mullin, Jennifer; Ahmed, Muhammed S; Sharma, Ravi; Upile, Navdeep; Beer, Helen; Achar, Priya; Puksuriwong, Suttida; Ferrara, Francesca; Temperton, Nigel; McNamara, Paul; Lambe, Teresa; Gilbert, Sarah C; Zhang, Qibo

    2016-03-29

    Recent efforts have been focused on the development of vaccines that could induce broad immunity against influenza virus, either through T cell responses to conserved internal antigens or B cell response to cross-reactive haemagglutinin (HA). We studied the capacity of Modified Vaccinia Ankara (MVA)-vectored influenza vaccines to induce cross-reactive immunity to influenza virus in human nasopharynx-associated lymphoid tissue (NALT) in vitro. Adenotonsillar cells were isolated and stimulated with MVA vaccines expressing either conserved nucleoprotein (NP) and matrix protein 1 (M1) (MVA-NP-M1) or pandemic H1N1 HA (MVA-pdmH1HA). The MVA vaccine uptake and expression, and T and B cell responses were analyzed. MVA-vectored vaccines were highly efficient infecting NALT and vaccine antigens were highly expressed by B cells. MVA-NP-M1 elicited T cell response with greater numbers of IFNγ-producing CD4+ T cells and tissue-resident memory T cells than controls. MVA-pdmH1HA induced cross-reactive anti-HA antibodies to a number of influenza subtypes, in an age-dependent manner. The cross-reactive antibodies include anti-avian H5N1 and mainly target HA2 domain. MVA vaccines are efficient in infecting NALT and the vaccine antigen is highly expressed by B cells. MVA vaccines expressing conserved influenza antigens induce cross-reactive T and B cell responses in human NALT in vitro, suggesting the potential as mucosal vaccines for broader immunity against influenza. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Development and trial of vaccines against Brucella.

    Science.gov (United States)

    Lalsiamthara, Jonathan; Lee, John Hwa

    2017-08-31

    The search for ideal brucellosis vaccines remains active today. Currently, no licensed human or canine anti-brucellosis vaccines are available. In bovines, the most successful vaccine (S19) is only used in calves, as adult vaccination results in orchitis in male, prolonged infection, and possible abortion complications in pregnant female cattle. Another widely deployed vaccine (RB51) has a low protective efficacy. An ideal vaccine should exhibit a safe profile as well as enhance protective efficacy. However, currently available vaccines exhibit one or more major drawbacks. Smooth live attenuated vaccines suffer shortcomings such as residual virulence and serodiagnostic interference. Inactivated vaccines, in general, confer relatively low levels of protection. Recent developments to improve brucellosis vaccines include generation of knockout mutants by targeting genes involved in metabolism, virulence, and the lipopolysaccharide synthesis pathway, as well as generation of DNA vaccines, mucosal vaccines, and live vectored vaccines, have all produced varying degrees of success. Herein, we briefly review the bacteriology, pathogenesis, immunological implications, candidate vaccines, vaccinations, and models related to Brucella .

  16. Rapid strategy for screening by pyrosequencing of influenza virus reassortants--candidates for live attenuated vaccines.

    Science.gov (United States)

    Shcherbik, Svetlana V; Pearce, Nicholas C; Levine, Marnie L; Klimov, Alexander I; Villanueva, Julie M; Bousse, Tatiana L

    2014-01-01

    Live attenuated influenza vaccine viruses (LAIVs) can be generated by classical reassortment of gene segments between a cold adapted, temperature sensitive and attenuated Master Donor Virus (MDV) and a seasonal wild-type (wt) virus. The vaccine candidates contain hemagglutinin (HA) and neuraminidase (NA) genes derived from the circulating wt viruses and the remaining six genes derived from the MDV strains. Rapid, efficient selection of the viruses with 6∶2 genome compositions from the large number of genetically different viruses generated during reassortment is essential for the biannual production schedule of vaccine viruses. This manuscript describes a new approach for the genotypic analysis of LAIV reassortant virus clones based on pyrosequencing. LAIV candidate viruses were created by classical reassortment of seasonal influenza A (H3N2) (A/Victoria/361/2011, A/Ohio/02/2012, A/Texas/50/2012) or influenza A (H7N9) (A/Anhui/1/2013) wt viruses with the MDV A/Leningrad/134/17/57(H2N2). Using strain-specific pyrosequencing assays, mixed gene variations were detected in the allantoic progenies during the cloning procedure. The pyrosequencing analysis also allowed for estimation of the relative abundance of segment variants in mixed populations. This semi-quantitative approach was used for selecting specific clones for the subsequent cloning procedures. The present study demonstrates that pyrosequencing analysis is a useful technique for rapid and reliable genotyping of reassortants and intermediate clones during the preparation of LAIV candidates, and can expedite the selection of vaccine virus candidates.

  17. Rapid strategy for screening by pyrosequencing of influenza virus reassortants--candidates for live attenuated vaccines.

    Directory of Open Access Journals (Sweden)

    Svetlana V Shcherbik

    Full Text Available BACKGROUND: Live attenuated influenza vaccine viruses (LAIVs can be generated by classical reassortment of gene segments between a cold adapted, temperature sensitive and attenuated Master Donor Virus (MDV and a seasonal wild-type (wt virus. The vaccine candidates contain hemagglutinin (HA and neuraminidase (NA genes derived from the circulating wt viruses and the remaining six genes derived from the MDV strains. Rapid, efficient selection of the viruses with 6∶2 genome compositions from the large number of genetically different viruses generated during reassortment is essential for the biannual production schedule of vaccine viruses. METHODOLOGY/PRINCIPAL FINDINGS: This manuscript describes a new approach for the genotypic analysis of LAIV reassortant virus clones based on pyrosequencing. LAIV candidate viruses were created by classical reassortment of seasonal influenza A (H3N2 (A/Victoria/361/2011, A/Ohio/02/2012, A/Texas/50/2012 or influenza A (H7N9 (A/Anhui/1/2013 wt viruses with the MDV A/Leningrad/134/17/57(H2N2. Using strain-specific pyrosequencing assays, mixed gene variations were detected in the allantoic progenies during the cloning procedure. The pyrosequencing analysis also allowed for estimation of the relative abundance of segment variants in mixed populations. This semi-quantitative approach was used for selecting specific clones for the subsequent cloning procedures. CONCLUSIONS/SIGNIFICANCE: The present study demonstrates that pyrosequencing analysis is a useful technique for rapid and reliable genotyping of reassortants and intermediate clones during the preparation of LAIV candidates, and can expedite the selection of vaccine virus candidates.

  18. Live attenuated measles virus vaccine therapy for locally established malignant glioblastoma tumor cells

    Directory of Open Access Journals (Sweden)

    Al-Shammari AM

    2014-05-01

    Full Text Available Ahmed M Al-Shammari,1 Farah E Ismaeel,2 Shahlaa M Salih,2 Nahi Y Yaseen11Experimental Therapy Department, Iraqi Center for Cancer and Medical Genetic Researches, Mustansiriya University, 2Departments of Biotechnology, College of Science, Al-Nahrain University, Baghdad, IraqAbstract: Glioblastoma multiforme is the most aggressive malignant primary brain tumor in humans, with poor prognosis. A new glioblastoma cell line (ANGM5 was established from a cerebral glioblastoma multiforme in a 72-year-old Iraqi man who underwent surgery for an intracranial tumor. This study was carried out to evaluate the antitumor effect of live attenuated measles virus (MV Schwarz vaccine strain on glioblastoma multiforme tumor cell lines in vitro. Live attenuated MV Schwarz strain was propagated on Vero, human rhabdomyosarcoma, and human glioblastoma-multiform (ANGM5 cell lines. The infected confluent monolayer appeared to be covered with syncytia with granulation and vacuolation, as well as cell rounding, shrinkage, and large empty space with cell debris as a result of cell lysis and death. Cell lines infected with virus have the ability for hemadsorption to human red blood cells after 72 hours of infection, whereas no hemadsorption of uninfected cells is seen. Detection of MV hemagglutinin protein by monoclonal antibodies in infected cells of all cell lines by immunocytochemistry assay gave positive results (brown color in the cytoplasm of infected cells. Cell viability was measured after 72 hours of infection by 3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay. Results showed a significant cytotoxic effect for MV (P≤0.05 on growth of ANGM5 and rhabdomyosarcoma cell lines after 72 hours of infection. Induction of apoptosis by MV was assessed by measuring mitochondrial membrane potentials in tumor cells after 48, 72, and 120 hours of infection. Apoptotic cells were counted, and the mean percentage of dead cells was significantly higher after 48, 72

  19. Suppressing active replication of a live attenuated simian immunodeficiency virus vaccine does not abrogate protection from challenge

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, Benjamin; Fiebig, Uwe; Hohn, Oliver [Robert Koch-Institut, Berlin (Germany); Plesker, Roland; Coulibaly, Cheick; Cichutek, Klaus; Mühlebach, Michael D. [Paul-Ehrlich-Institut, Langen (Germany); Bannert, Norbert; Kurth, Reinhard [Robert Koch-Institut, Berlin (Germany); Norley, Stephen, E-mail: NorleyS@rki.de [Robert Koch-Institut, Berlin (Germany)

    2016-02-15

    Although safety concerns preclude the use of live attenuated HIV vaccines in humans, they provide a useful system for identifying the elusive correlates of protective immunity in the SIV/macaque animal model. However, a number of pieces of evidence suggest that protection may result from prior occupancy of susceptible target cells by the vaccine virus rather than the immune response. To address this, we developed a Nef-deletion variant of an RT-SHIV whose active replication could be shut off by treatment with RT-inhibitors. Groups of macaques were inoculated with the ∆Nef-RT-SHIV and immune responses allowed to develop before antiretroviral treatment and subsequent challenge with wild-type SIVmac239. Vaccinated animals either resisted infection fully or significantly controlled the subsequent viremia. However, there was no difference between animals undergoing replication of the vaccine virus and those without. This strongly suggests that competition for available target cells does not play a role in protection. - Highlights: • A Nef-deleted RT-SHIV was used as a live attenuated vaccine in macaques. • Vaccine virus replication was shut down to investigate its role in protection. • Ongoing vaccine virus replication did not appear to be necessary for protection. • An analysis of T- and B-cell responses failed to identify a correlate of protection.

  20. Suppressing active replication of a live attenuated simian immunodeficiency virus vaccine does not abrogate protection from challenge

    International Nuclear Information System (INIS)

    Gabriel, Benjamin; Fiebig, Uwe; Hohn, Oliver; Plesker, Roland; Coulibaly, Cheick; Cichutek, Klaus; Mühlebach, Michael D.; Bannert, Norbert; Kurth, Reinhard; Norley, Stephen

    2016-01-01

    Although safety concerns preclude the use of live attenuated HIV vaccines in humans, they provide a useful system for identifying the elusive correlates of protective immunity in the SIV/macaque animal model. However, a number of pieces of evidence suggest that protection may result from prior occupancy of susceptible target cells by the vaccine virus rather than the immune response. To address this, we developed a Nef-deletion variant of an RT-SHIV whose active replication could be shut off by treatment with RT-inhibitors. Groups of macaques were inoculated with the ∆Nef-RT-SHIV and immune responses allowed to develop before antiretroviral treatment and subsequent challenge with wild-type SIVmac239. Vaccinated animals either resisted infection fully or significantly controlled the subsequent viremia. However, there was no difference between animals undergoing replication of the vaccine virus and those without. This strongly suggests that competition for available target cells does not play a role in protection. - Highlights: • A Nef-deleted RT-SHIV was used as a live attenuated vaccine in macaques. • Vaccine virus replication was shut down to investigate its role in protection. • Ongoing vaccine virus replication did not appear to be necessary for protection. • An analysis of T- and B-cell responses failed to identify a correlate of protection.

  1. Vector optimization and needle-free intradermal application of a broadly protective polyvalent influenza A DNA vaccine for pigs and humans

    DEFF Research Database (Denmark)

    Borggren, Marie; Nielsen, Jens; Bragstad, Karoline

    2015-01-01

    such as the induction of cellular and humoral immunity, inherent safety and rapid production time. We have previously developed a DNA vaccine encoding selected influenza proteins of pandemic origin and demonstrated broad protective immune responses in ferrets and pigs. In this study, we evaluated our DNA vaccine......The threat posed by the 2009 pandemic H1N1 virus emphasized the need for new influenza A virus vaccines inducing a broad cross-protective immune response for use in both humans and pigs. An effective and broad influenza vaccine for pigs would greatly benefit the pork industry and contribute...... to public health by diminishing the risk of emerging highly pathogenic reassortants. Current inactivated protein vaccines against swine influenza produce only short-lived immunity and have no efficacy against heterologous strains. DNA vaccines are a potential alternative with advantages...

  2. Protection of chickens against H5N1 highly pathogenic avian influenza virus infection by live vaccination with infectious laryngotracheitis virus recombinants expressing H5 hemagglutinin and N1 neuraminidase.

    Science.gov (United States)

    Pavlova, Sophia P; Veits, Jutta; Keil, Günther M; Mettenleiter, Thomas C; Fuchs, Walter

    2009-01-29

    Attenuated vaccine strains of the alphaherpesvirus causing infectious laryngotracheitis of chickens (ILTV, gallid herpesvirus 1) can be used for mass application. Previously, we showed that live virus vaccination with recombinant ILTV expressing hemagglutinin of highly pathogenic avian influenza viruses (HPAIV) protected chickens against ILT and fowl plague caused by HPAIV carrying the corresponding hemagglutinin subtypes [Lüschow D, Werner O, Mettenleiter TC, Fuchs W. Protection of chickens from lethal avian influenza A virus infection by live-virus vaccination with infectious laryngotracheitis virus recombinants expressing the hemagglutinin (H5) gene. Vaccine 2001;19(30):4249-59; Veits J, Lüschow D, Kindermann K, Werner O, Teifke JP, Mettenleiter TC, et al. Deletion of the non-essential UL0 gene of infectious laryngotracheitis (ILT) virus leads to attenuation in chickens, and UL0 mutants expressing influenza virus haemagglutinin (H7) protect against ILT and fowl plague. J Gen Virol 2003;84(12):3343-52]. However, protection against H5N1 HPAIV was not satisfactory. Therefore, a newly designed dUTPase-negative ILTV vector was used for rapid insertion of the H5-hemagglutinin, or N1-neuraminidase genes of a recent H5N1 HPAIV isolate. Compared to our previous constructs, protein expression was considerably enhanced by insertion of synthetic introns downstream of the human cytomegalovirus immediate-early promoter within the 5'-nontranslated region of the transgenes. Deletion of the viral dUTPase gene did not affect in vitro replication of the ILTV recombinants, but led to sufficient attenuation in vivo. After a single ocular immunization, all chickens developed H5- or N1-specific serum antibodies. Nevertheless, animals immunized with N1-ILTV died after subsequent H5N1 HPAIV challenge, although survival times were prolonged compared to non-vaccinated controls. In contrast, all chickens vaccinated with either H5-ILTV alone, or H5- and N1-ILTV simultaneously, survived

  3. Monitoring vaccine and non-vaccine HPV type prevalence in the post-vaccination era in women living in the Basilicata region, Italy.

    Science.gov (United States)

    Carozzi, Francesca; Puliti, Donella; Ocello, Cristina; Anastasio, Pasquale Silvio; Moliterni, Espedito Antonio; Perinetti, Emilia; Serradell, Laurence; Burroni, Elena; Confortini, Massimo; Mantellini, Paola; Zappa, Marco; Dominiak-Felden, Géraldine

    2018-01-15

    A large free-of-charge quadrivalent HPV (qHPV) vaccination program, covering four cohorts annually (women 11, 14, 17 and 24 years), has been implemented in Basilicata since 2007. This study evaluated vaccine and non-vaccine HPV prevalence 5-7 years post-vaccination program implementation in vaccinated and unvaccinated women. This population-based, cross-sectional study was conducted in the public screening centers of the Local Health Unit in Matera between 2012 and 2014. Cervical samples were obtained for Pap and HPV testing (HC2, LiPA Extra® assay) and participants completed a sociodemographic and behavioral questionnaire. Detailed HPV vaccination status was retrieved from the official HPV vaccine registry. HPV prevalence was described overall, by type and vaccination status. The association between HPV type-detection and risk/protective factors was studied. Direct vaccine protection (qHPV vaccine effectiveness [VE]), cross-protection, and type-replacement were evaluated in cohorts eligible for vaccination, by analyzing HPV prevalence of vaccine and non-vaccine types according to vaccination status. Overall, 2793 women (18-50 years) were included, 1314 of them having been in birth cohorts eligible for the HPV vaccination program (18- to 30-year-old women at enrolment). Among the latter, qHPV vaccine uptake was 59% (at least one dose), with 94% completing the schedule; standardized qHPV type prevalence was 0.6% in vaccinated versus 5.5% in unvaccinated women (P HPV, high-risk non-vaccine HPV, or any single non-vaccine type prevalence was observed between vaccinated and unvaccinated women. These results, conducted in a post-vaccine era, suggest a high qHPV VE and that a well-implemented catch-up vaccination program may be efficient in reducing vaccine-type infections in a real-world setting. No cross-protective effect or evidence of type-replacement was observed a few years after HPV vaccine introduction.

  4. Expression of chicken parvovirus VP2 in chicken embryo fibroblasts requires codon optimization for production of naked DNA and vectored Meleagrid herpesvirus type 1 vaccines

    Science.gov (United States)

    Meleagrid herpesvirus type 1 (MeHV-1) is an ideal vector for the expression of antigens from pathogenic avian organisms in order to generate vaccines. Chicken parvovirus (ChPV) is a widespread infectious virus that causes serious disease in chickens. It is one of the etiological agents largely suspe...

  5. Have we found an optimal insertion site in a Newcastle disease virus vector to express a foreign gene for vaccine and gene therapy purposes?

    Science.gov (United States)

    Using reverse genetics technology, many strains of Newcastle disease virus (NDV) have been developed as vectors to express foreign genes for vaccine and gene therapy purposes. The foreign gene is usually inserted into a non-coding region of the NDV genome as an independent transcription unit. Eval...

  6. Duration of immunity in red wolves (Canis rufus) following vaccination with a modified live parvovirus and canine distemper vaccine.

    Science.gov (United States)

    Anderson, Kadie; Case, Allison; Woodie, Kathleen; Waddell, William; Reed, Holly H

    2014-09-01

    There is growing information available regarding duration of immunity for core vaccines in both domestic and nondomestic species. Vaccination protocols in nondomestic canids have frequently followed guidelines developed for the domestic dog; however, these protocols can be inappropriate for nondomestic canids such as the African wild dog (Lycaon pictus), leaving some animals susceptible to infectious disease and others at risk for contracting vaccine-induced disease. In this study, red wolves (Canis rufus) were vaccinated against canine distemper virus (CDV) and canine parvovirus (CPV) and vaccination titers were followed annually for 3 yr. One hundred percent of wolves developed and maintained a positive titer to CDV for 3 yr and 96.9% of wolves developed and maintained a positive titer to CPV for 3 yr. Seroconversion for canine adenovirus was sporadic. The results of this study support decreasing the frequency of vaccine administration in the red wolf population to a triennial basis.

  7. The yellow fever 17D vaccine virus: molecular basis of viral attenuation and its use as an expression vector

    Directory of Open Access Journals (Sweden)

    Galler R.

    1997-01-01

    Full Text Available The yellow fever (YF virus is the prototype flavivirus. The use of molecular techniques has unraveled the basic mechanisms of viral genome structure and expression. Recent trends in flavivirus research include the use of infectious clone technology with which it is possible to recover virus from cloned cDNA. Using this technique, mutations can be introduced at any point of the viral genome and their resulting effect on virus phenotype can be assessed. This approach has opened new possibilities to study several biological viral features with special emphasis on the issue of virulence/attenuation of the YF virus. The feasibility of using YF virus 17D vaccine strain, for which infectious cDNA is available, as a vector for the expression of heterologous antigens is reviewed

  8. HIV vaccines: new frontiers in vaccine development.

    Science.gov (United States)

    Duerr, Ann; Wasserheit, Judith N; Corey, Lawrence

    2006-08-15

    A human immunodeficiency virus (HIV) vaccine is the most promising and feasible strategy to prevent the events during acute infection that simultaneously set the course of the epidemic in the community and the course of the disease for the individual. Because safety concerns limit the use of live, attenuated HIV and inactivated HIV, a variety of alternate approaches is being investigated. Traditional antibody-mediated approaches using recombinant HIV envelope proteins have shown no efficacy in 2 phase III trials. Current HIV vaccine trials are focusing primarily on cytotoxic T lymphocyte-mediated products that use viral vectors, either alone or as boosts to DNA plasmids that contain viral genes. The most immunogenic of these products appear to be the recombinant adenovirus vector vaccines, 2 of which are now in advanced clinical development.

  9. Transduction of liver cells by lentiviral vectors: analysis in living animals by fluorescence imaging

    NARCIS (Netherlands)

    Pfeifer, A.; Kessler, T.; Yang, M.; Baranov, E.; Kootstra, N.; Cheresh, D. A.; Hoffman, R. M.; Verma, I. M.

    2001-01-01

    Viral vectors based on lentiviruses, such as the human immunodeficiency virus, are able to transduce a broad spectrum of nondividing cells in vivo. This ability of lentiviral vectors makes them an attractive vehicle for gene transfer into the liver. In order to determine the requirements for

  10. Protective efficacy of a single immunization with capripoxvirus-vectored recombinant peste des petits ruminants vaccines in presence of pre-existing immunity.

    Science.gov (United States)

    Caufour, Philippe; Rufael, Tesfaye; Lamien, Charles Euloge; Lancelot, Renaud; Kidane, Menbere; Awel, Dino; Sertse, Tefera; Kwiatek, Olivier; Libeau, Geneviève; Sahle, Mesfin; Diallo, Adama; Albina, Emmanuel

    2014-06-24

    Sheeppox, goatpox and peste des petits ruminants (PPR) are highly contagious ruminant diseases widely distributed in Africa, the Middle East and Asia. Capripoxvirus (CPV)-vectored recombinant PPR vaccines (rCPV-PPR vaccines), which have been developed and shown to protect against both Capripox (CP) and PPR, would be critical tools in the control of these important diseases. In most parts of the world, these disease distributions overlap each other leaving concerns about the potential impact that pre-existing immunity against either disease may have on the protective efficacy of these bivalent rCPV-PPR vaccines. Currently, this question has not been indisputably addressed. Therefore, we undertook this study, under experimental conditions designed for the context of mass vaccination campaigns of small ruminants, using the two CPV recombinants (Kenya sheep-1 (KS-1) strain-based constructs) developed previously in our laboratory. Pre-existing immunity was first induced by immunization either with an attenuated CPV vaccine strain (KS-1) or the attenuated PPRV vaccine strain (Nigeria 75/1) and animals were thereafter inoculated once subcutaneously with a mixture of CPV recombinants expressing either the hemagglutinin (H) or the fusion (F) protein gene of PPRV (10(3) TCID50/animal of each). Finally, these animals were challenged with a virulent CPV strain followed by a virulent PPRV strain 3 weeks later. Our study demonstrated full protection against CP for vaccinated animals with prior exposure to PPRV and a partial protection against PPR for vaccinated animals with prior exposure to CPV. The latter animals exhibited a mild clinical form of PPR and did not show any post-challenge anamnestic neutralizing antibody response against PPRV. The implications of these results are discussed herein and suggestions made for future research regarding the development of CPV-vectored vaccines. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Apparent field safety of a raccoon poxvirus-vectored plague vaccine in free-ranging prairie dogs (Cynomys spp.), Colorado, USA.

    Science.gov (United States)

    Tripp, Daniel W; Rocke, Tonie E; Streich, Sean P; Abbott, Rachel C; Osorio, Jorge E; Miller, Michael W

    2015-04-01

    Prairie dogs (Cynomys spp.) suffer high rates of mortality from plague. An oral sylvatic plague vaccine using the raccoon poxvirus vector (designated RCN-F1/V307) has been developed for prairie dogs. This vaccine is incorporated into palatable bait along with rhodamine B as a biomarker. We conducted trials in August and September 2012 to demonstrate uptake and apparent safety of the RCN-F1/V307 vaccine in two prairie dog species under field conditions. Free-ranging prairie dogs and other associated small rodents readily consumed vaccine-laden baits during field trials with no apparent adverse effects; most sampled prairie dogs (90%) and associated small rodents (78%) had consumed baits. Visual counts of prairie dogs and their burrows revealed no evidence of prairie dog decline after vaccine exposure. No vaccine-related morbidity, mortality, or gross or microscopic lesions were observed. Poxviruses were not isolated from any animal sampled prior to bait distribution or on sites that received placebo baits. We isolated RCN-F1/V307 from 17 prairie dogs and two deer mice (Peromyscus maniculatus) captured on sites where vaccine-laden baits were distributed. Based on these findings, studies examining the utility and effectiveness of oral vaccination to prevent plague-induced mortality in prairie dogs and associated species are underway.

  12. Apparent field safety of a raccoon poxvirus-vectored plague vaccine in free-ranging prairie dogs (Cynomys spp.), Colorado, USA

    Science.gov (United States)

    Tripp, Daniel W.; Rocke, Tonie E.; Streich, Sean P.; Abbott, Rachel C.; Osorio, Jorge E.; Miller, Michael W.

    2015-01-01

    Prairie dogs (Cynomys spp.) suffer high rates of mortality from plague. An oral sylvatic plague vaccine using the raccoon poxvirus vector (designated RCN-F1/V307) has been developed for prairie dogs. This vaccine is incorporated into palatable bait along with rhodamine B as a biomarker. We conducted trials in August and September 2012 to demonstrate uptake and apparent safety of the RCN-F1/V307 vaccine in two prairie dog species under field conditions. Free-ranging prairie dogs and other associated small rodents readily consumed vaccine-laden baits during field trials with no apparent adverse effects; most sampled prairie dogs (90%) and associated small rodents (78%) had consumed baits. Visual counts of prairie dogs and their burrows revealed no evidence of prairie dog decline after vaccine exposure. No vaccine-related morbidity, mortality, or gross or microscopic lesions were observed. Poxviruses were not isolated from any animal sampled prior to bait distribution or on sites that received placebo baits. We isolated RCN-F1/V307 from 17 prairie dogs and two deer mice (Peromyscus maniculatus) captured on sites where vaccine-laden baits were distributed. Based on these findings, studies examining the utility and effectiveness of oral vaccination to prevent plague-induced mortality in prairie dogs and associated species are underway.

  13. Apple Latent Spherical Virus Vector as Vaccine for the Prevention and Treatment of Mosaic Diseases in Pea, Broad Bean, and Eustoma Plants by Bean Yellow Mosaic Virus

    Directory of Open Access Journals (Sweden)

    Nozomi Satoh

    2014-11-01

    Full Text Available We investigated the protective effects of a viral vector based on an Apple latent spherical virus (ALSV harboring a segment of the Bean yellow mosaic virus (BYMV genome against mosaic diseases in pea, broad bean, and eustoma plants caused by BYMV infection. In pea plants pre-inoculated with the ALSV vaccine and challenge inoculated with BYMV expressing green fluorescence protein, BYMV multiplication occurred in inoculated leaves, but was markedly inhibited in the upper leaves. No mosaic symptoms due to BYMV infection were observed in the challenged plants pre-inoculated with the ALSV vaccine. Simultaneous inoculation with the ALSV vaccine and BYMV also prevented mosaic symptoms in broad bean and eustoma plants, and BYMV accumulation was strongly inhibited in the upper leaves of plants treated with the ALSV vaccine. Pea and eustoma plants were pre-inoculated with BYMV followed by inoculation with the ALSV vaccine to investigate the curative effects of the ALSV vaccine. In both plant species, recovery from mosaic symptoms was observed in upper leaves and BYMV accumulation was inhibited in leaves developing post-ALSV vaccination. These results show that ALSV vaccination not only prevents mosaic diseases in pea, broad bean, and eustoma, but that it is also effective in curing these diseases.

  14. Properties of a herpes simplex virus multiple immediate-early gene-deleted recombinant as a vaccine vector

    International Nuclear Information System (INIS)

    Watanabe, Daisuke; Brockman, Mark A.; Ndung'u, Thumbi; Mathews, Lydia; Lucas, William T.; Murphy, Cynthia G.; Felber, Barbara K.; Pavlakis, George N.; Deluca, Neal A.; Knipe, David M.

    2007-01-01

    Herpes simplex virus (HSV) recombinants induce durable immune responses in rhesus macaques and mice and have induced partial protection in rhesus macaques against mucosal challenge with virulent simian immunodeficiency virus (SIV). In this study, we evaluated the properties of a new generation HSV vaccine vector, an HSV-1 multiple immediate-early (IE) gene deletion mutant virus, d106, which contains deletions in the ICP4, ICP27, ICP22, and ICP47 genes. Because several of the HSV IE genes have been implicated in immune evasion, inactivation of the genes encoding these proteins was expected to result in enhanced immunogenicity. The d106 virus expresses few HSV gene products and shows minimal cytopathic effect in cultured cells. When d106 was inoculated into mice, viral DNA accumulated at high levels in draining lymph nodes, consistent with an ability to transduce dendritic cells and activate their maturation and movement to lymph nodes. A d106 recombinant expressing Escherichia coli β-galactosidase induced durable β-gal-specific IgG and CD8 + T cell responses in naive and HSV-immune mice. Finally, d106-based recombinants have been constructed that express simian immunodeficiency virus (SIV) gag, env, or a rev-tat-nef fusion protein for several days in cultured cells. Thus, d106 shows many of the properties desirable in a vaccine vector: limited expression of HSV gene products and cytopathogenicity, high level expression of transgenes, ability to induce durable immune responses, and an ability to transduce dendritic cells and induce their maturation and migration to lymph nodes

  15. [History of development of the live poliomyelitis vaccine from Sabin attenuated strains in 1959 and idea of poliomyelitis eradication].

    Science.gov (United States)

    Lashkevich, V A

    2013-01-01

    In 1958 Poliomyelitis Institute in Moscow and Institute of Experimental Medicine in St. Petersburg received from A. Sabin the attenuated strains of poliomyelitis virus. The characteristics of the strains were thoroughly studied by A. A. Smorodintsev and coworkers. They found that the virulence of the strains fluctuated slightly in 10 consecutive passages through the intestine of the non-immune children. A part of the Sabin material was used by A. A. Smorodintsev and M. P. Chumakov in the beginning of 1959 for immunizing approximately 40000 children in Estonia, Lithuania, and Latvia. Epidemic poliomyelitis rate in these republics decreased from approximately 1000 cases yearly before vaccination to less than 20 in the third quarter of 1959. This was a convincing proof of the efficacy and safety of the vaccine from the attenuated Sabin strains. In 1959, according to A. Sabin's recommendation, a technology of live vaccine production was developed at the Poliomyelitis Institute, and several experimental lots of vaccine were prepared. In the second part of 1959, 13.5 million children in USSR were immunized. The epidemic poliomyelitis rate decreased 3-5 times in different regions without paralytic cases, which could be attributed to the vaccination. These results were the final proof of high efficiency and safety of live poliomyelitis vaccine from the attenuated Sabin strains. Based on these results, A. Sabin and M. P. Chumakov suggested in 1960 the idea of poliomyelitis eradication using mass immunization of children with live vaccine. 72 million persons up to 20 years old were vaccinated in USSR in 1960 with a 5 times drop in the paralytic rate. 50-year-long use of live vaccine results in poliomyelitis eradication in almost all countries worldwide. More than 10 million children were rescued from the death and palsy. Poliomyelitis eradication in a few countries where it still exists depends not on medical services but is defined by the attitude of their leaders to fight

  16. Comparative immunological evaluation of recombinant Salmonella Typhimurium strains expressing model antigens as live oral vaccines.

    Science.gov (United States)

    Zheng, Song-yue; Yu, Bin; Zhang, Ke; Chen, Min; Hua, Yan-Hong; Yuan, Shuofeng; Watt, Rory M; Zheng, Bo-Jian; Yuen, Kwok-Yung; Huang, Jian-Dong

    2012-09-26

    Despite the development of various systems to generate live recombinant Salmonella Typhimurium vaccine strains, little work has been performed to systematically evaluate and compare their relative immunogenicity. Such information would provide invaluable guidance for the future rational design of live recombinant Salmonella oral vaccines. To compare vaccine strains encoded with different antigen delivery and expression strategies, a series of recombinant Salmonella Typhimurium strains were constructed that expressed either the enhanced green fluorescent protein (EGFP) or a fragment of the hemagglutinin (HA) protein from the H5N1 influenza virus, as model antigens. The antigens were expressed from the chromosome, from high or low-copy plasmids, or encoded on a eukaryotic expression plasmid. Antigens were targeted for expression in either the cytoplasm or the outer membrane. Combinations of strategies were employed to evaluate the efficacy of combined delivery/expression approaches. After investigating in vitro and in vivo antigen expression, growth and infection abilities; the immunogenicity of the constructed recombinant Salmonella strains was evaluated in mice. Using the soluble model antigen EGFP, our results indicated that vaccine strains with high and stable antigen expression exhibited high B cell responses, whilst eukaryotic expression or colonization with good construct stability was critical for T cell responses. For the insoluble model antigen HA, an outer membrane expression strategy induced better B cell and T cell responses than a cytoplasmic strategy. Most notably, the combination of two different expression strategies did not increase the immune response elicited. Through systematically evaluating and comparing the immunogenicity of the constructed recombinant Salmonella strains in mice, we identified their respective advantages and deleterious or synergistic effects. Different construction strategies were optimally-required for soluble versus

  17. Immunogenicity of a low-passage, high-titer modified live canine parvovirus vaccine in pups with maternally derived antibodies.

    Science.gov (United States)

    Hoare, C M; DeBouck, P; Wiseman, A

    1997-02-01

    The study evaluated the ability of a low-passage, high-titer modified live canine parvovirus (CPV) vaccine to produce seroconversion in pups with maternally derived hemagglutination inhibition (HI) titers ranging from attenuated and therefore more infective than conventional modified live CPV strains in order to overcome relatively greater levels of maternally derived antibodies, the principal cause of CPV vaccine failures in pups. To assess vaccine performance under field conditions, healthy pups presented at five private veterinary clinics were used as test animals. A single dose of vaccine was given to 59 pups at 12 weeks of age (Group A). To accommodate the protocol of clinics where earlier CPV vaccination was practiced, 87 other pups were vaccinated with two doses, the first at 8-10 weeks of age, and the second at 12 weeks of age (Group B). Geometric mean HI titers were measured for blood samples obtained at the time of vaccination and at 14 weeks of age. Seroconversion was considered to have occurred if pups developed a fourfold or greater increase in HI titer to a level > or = 64. Of the 59 pups in Group A, 100% seroconverted following the single vaccine dose at 12 weeks of age. Of the 87 Group B pups, 82 (94.3%) seroconverted following either of the two vaccine doses. A geometric mean HI titer of 4828 was measured for Group A, and a geometric mean HI titer of 2028 was measured for Group B. An overall seroconversion rate of 96.5% was achieved in pups with maternally derived HI titers < or = 256.

  18. The epidemiological impact of childhood influenza vaccination using live-attenuated influenza vaccine (LAIV) in Germany: predictions of a simulation study

    Science.gov (United States)

    2014-01-01

    Background Routine annual influenza vaccination is primarily recommended for all persons aged 60 and above and for people with underlying chronic conditions in Germany. Other countries have already adopted additional childhood influenza immunisation programmes. The objective of this study is to determine the potential epidemiological impact of implementing paediatric influenza vaccination using intranasally administered live-attenuated influenza vaccine (LAIV) in Germany. Methods A deterministic age-structured model is used to simulate the population-level impact of different vaccination strategies on the transmission dynamics of seasonal influenza in Germany. In our base-case analysis, we estimate the effects of adding a LAIV-based immunisation programme targeting children 2 to 17 years of age to the existing influenza vaccination policy. The data used in the model is based on published evidence complemented by expert opinion. Results In our model, additional vaccination of children 2 to 17 years of age with LAIV leads to the prevention of 23.9 million influenza infections and nearly 16 million symptomatic influenza cases within 10 years. This reduction in burden of disease is not restricted to children. About one third of all adult cases can indirectly be prevented by LAIV immunisation of children. Conclusions Our results demonstrate that vaccinating children 2–17 years of age is likely associated with a significant reduction in the burden of paediatric influenza. Furthermore, annual routine childhood vaccination against seasonal influenza is expected to decrease the incidence of influenza among adults and older people due to indirect effects of herd protection. In summary, our model provides data supporting the introduction of a paediatric influenza immunisation programme in Germany. PMID:24450996

  19. Live, Attenuated Influenza A H5N1 Candidate Vaccines Provide Broad Cross-Protection in Mice and Ferrets

    Science.gov (United States)

    Mills, Kimberly L; Jin, Hong; Duke, Greg; Lu, Bin; Luke, Catherine J; Murphy, Brian; Swayne, David E; Kemble, George; Subbarao, Kanta

    2006-01-01

    Background Recent outbreaks of highly pathogenic influenza A H5N1 viruses in humans and avian species that began in Asia and have spread to other continents underscore an urgent need to develop vaccines that would protect the human population in the event of a pandemic. Methods and Findings Live, attenuated candidate vaccines possessing genes encoding a modified H5 hemagglutinin (HA) and a wild-type (wt) N1 neuraminidase from influenza A H5N1 viruses isolated in Hong Kong and Vietnam in 1997, 2003, and 2004, and remaining gene segments derived from the cold-adapted (ca) influenza A vaccine donor strain, influenza A/Ann Arbor/6/60 ca (H2N2), were generated by reverse genetics. The H5N1 ca vaccine viruses required trypsin for efficient growth in vitro, as predicted by the modification engineered in the gene encoding the HA, and possessed the temperature-sensitive and attenuation phenotypes specified by the internal protein genes of the ca vaccine donor strain. More importantly, the candidate vaccines were immunogenic in mice. Four weeks after receiving a single dose of 106 50% tissue culture infectious doses of intranasally administered vaccines, mice were fully protected from lethality following challenge with homologous and antigenically distinct heterologous wt H5N1 viruses from different genetic sublineages (clades 1, 2, and 3) that were isolated in Asia between 1997 and 2005. Four weeks after receiving two doses of the vaccines, mice and ferrets were fully protected against pulmonary replication of homologous and heterologous wt H5N1 viruses. Conclusions The promising findings in these preclinical studies of safety, immunogenicity, and efficacy of the H5N1 ca vaccines against antigenically diverse H5N1 vaccines provide support for their careful evaluation in Phase 1 clinical trials in humans. PMID:16968127

  20. Live, attenuated influenza A H5N1 candidate vaccines provide broad cross-protection in mice and ferrets.

    Directory of Open Access Journals (Sweden)

    Amorsolo L Suguitan

    2006-09-01

    Full Text Available Recent outbreaks of highly pathogenic influenza A H5N1 viruses in humans and avian species that began in Asia and have spread to other continents underscore an urgent need to develop vaccines that would protect the human population in the event of a pandemic.Live, attenuated candidate vaccines possessing genes encoding a modified H5 hemagglutinin (HA and a wild-type (wt N1 neuraminidase from influenza A H5N1 viruses isolated in Hong Kong and Vietnam in 1997, 2003, and 2004, and remaining gene segments derived from the cold-adapted (ca influenza A vaccine donor strain, influenza A/Ann Arbor/6/60 ca (H2N2, were generated by reverse genetics. The H5N1 ca vaccine viruses required trypsin for efficient growth in vitro, as predicted by the modification engineered in the gene encoding the HA, and possessed the temperature-sensitive and attenuation phenotypes specified by the internal protein genes of the ca vaccine donor strain. More importantly, the candidate vaccines were immunogenic in mice. Four weeks after receiving a single dose of 10(6 50% tissue culture infectious doses of intranasally administered vaccines, mice were fully protected from lethality following challenge with homologous and antigenically distinct heterologous wt H5N1 viruses from different genetic sublineages (clades 1, 2, and 3 that were isolated in Asia between 1997 and 2005. Four weeks after receiving two doses of the vaccines, mice and ferrets were fully protected against pulmonary replication of homologous and heterologous wt H5N1 viruses.The promising findings in these preclinical studies of safety, immunogenicity, and efficacy of the H5N1 ca vaccines against antigenically diverse H5N1 vaccines provide support for their careful evaluation in Phase 1 clinical trials in humans.

  1. In a randomized trial, the live attenuated tetravalent dengue vaccine TV003 is well-tolerated and highly immunogenic in subjects with flavivirus exposure prior to vaccination.

    Directory of Open Access Journals (Sweden)

    Stephen S Whitehead

    2017-05-01

    Full Text Available Infection caused by the four serotypes of dengue virus (DENV-1-4 is a leading cause of mosquito-borne disease. Clinically-severe dengue disease is more common when secondary dengue infection occurs following prior infection with a heterologous dengue serotype. Other flaviviruses such as yellow fever virus, Japanese encephalitis virus, and Zika virus, can also elicit antibodies which are cross-reactive to DENV. As candidate dengue vaccines become available in endemic settings and for individuals who have received other flavivirus vaccines, it is important to examine vaccine safety and immunogenicity in these flavivirus-experienced populations. We performed a randomized, controlled trial of the National Institutes of Health live attenuated tetravalent dengue vaccine candidate (TV003 in fifty-eight individuals with prior exposure to flavivirus infection or vaccine. As in prior studies of this vaccine in flavivirus-naive volunteers, flavivirus-experienced subjects received two doses of vaccine six months apart and were followed closely for clinical events, laboratory changes, viremia, and neutralizing antibody titers. TV003 was well tolerated with few adverse events other than rash, which was predominately mild. Following one dose, 87% of vaccinees had an antibody response to all four serotypes (tetravalent response, suggesting a robust immune response. In addition, 76% of vaccinees were viremic; mean peak titers ranged from 0.68–1.1 log10 PFU/mL and did not differ by serotype. The second dose of TV003 was not associated with viremia, rash, or a sustained boost in antibody titers indicating that a single dose of the vaccine is likely sufficient to prevent viral replication and thus protect against disease. In comparison to the viremia and neutralizing antibody response elicited by TV003 in flavivirus-naïve subjects from prior studies, we found that subjects who were flavivirus-exposed prior to vaccination exhibited slightly higher DENV-3 viremia

  2. Serologic evaluation, efficacy, and safety of a commerical modified-live canine distemper vaccine in domestic ferrets.

    Science.gov (United States)

    Wimsatt, J; Jay, M T; Innes, K E; Jessen, M; Collins, J K

    2001-05-01

    To determine efficacy and safety of a commercial modified-live canine distemper virus (CDV) vaccine used for prophylaxis in domestic ferrets. Sixteen 16-week-old neutered male ferrets. Equal groups of ferrets were inoculated subcutaneously at 16 and 20 weeks of age with saline (0.9% NaCl) solution or a vaccine derived from the Onderstepoort CDV strain and attenuated in a primate cell line. Live virulent CDV was administered to all ferrets intranasally and orally 3 weeks after the second inoculation. Clinical signs and body weights were monitored regularly during the study. Blood samples for serologic examination were drawn prior to each inoculation, before challenge exposure, and 10, 15, and 21 days after exposure. Blood samples for reverse transcriptase polymerase chain reaction (RT-PCR) were obtained 5 days after the first vaccination, and 5, 10, 15, and 21 days after challenge exposure. After challenge exposure, control ferrets had significantly more clinical signs and weight loss, compared with vaccinates. All vaccinated ferrets survived, whereas all control ferrets died. The RT-PCR assay was successful in detecting CDV in blood and fresh or formalin-fixed tissues from infected ferrets. Findings suggest that the vaccine when given SC to domestic ferrets as directed is safe and protective against challenge exposure with virulent CDV. The RT-PCR assay may simplify detection of CDV in fresh and fixed tissues.

  3. Safety of live attenuated influenza vaccine in atopic children with egg allergy.

    Science.gov (United States)

    Turner, Paul J; Southern, Jo; Andrews, Nick J; Miller, Elizabeth; Erlewyn-Lajeunesse, Michel

    2015-08-01

    Live attenuated influenza vaccine (LAIV) is an intranasal vaccine recently incorporated into the United Kingdom immunization schedule. However, it contains egg protein and, in the absence of safety data, is contraindicated in patients with egg allergy. Furthermore, North American guidelines recommend against its use in asthmatic children. We sought to assess the safety of LAIV in children with egg allergy. We performed a prospective, multicenter, open-label, phase IV intervention study involving 11 secondary/tertiary centers in the United Kingdom. Children with egg allergy (defined as a convincing clinical reaction to egg within the past 12 months and/or >95% likelihood of clinical egg allergy as per published criteria) were recruited. LAIV was administered under medical supervision, with observation for 1 hour and telephone follow-up 72 hours later. Four hundred thirty-three doses were administered to 282 children with egg allergy (median, 4.9 years; range, 2-17 years); 115 (41%) had experienced prior anaphylaxis to egg. A physician's diagnosis of asthma/recurrent wheezing was noted in 67%, and 51% were receiving regular preventer therapy. There were no systemic allergic reactions (upper 95% CI for population, 1.3%). Eight children experienced mild self-limiting symptoms, which might have been due an IgE-mediated allergic reaction. Twenty-six (9.4%; 95% CI for population, 6.2% to 13.4%) children experienced lower respiratory tract symptoms within 72 hours, including 13 with parent-reported wheeze. None of these episodes required medical intervention beyond routine treatment. In contrast to current recommendations, LAIV appears to be safe for use in children with egg allergy. Furthermore, the vaccine appears to be well tolerated in children with a diagnosis of asthma or recurrent wheeze. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Bacteroides Fragilis OmpA: Utility as a Live Vaccine Vector for Biodefense Agents

    Science.gov (United States)

    2009-01-01

    prominent pathogen in adult periodontal diseases 62 (Mineoka et al., 2008). OmpA proteins are among the most conserved of all OMPs in bacteria and consist...only involves growing the modified bacteria . We have met these goals and using recent and novel advances in cloning techniques, designed several...seen a precipitous rise in the percentages of multi- antimicrobial resistant bacteria . Over the past 15 years, scientists have developed experimental

  5. QA prime-boost vaccination strategy in prevent serotype O FMDV infection using a "single-cycle" alphavirus vector and empty capsid particles

    DEFF Research Database (Denmark)

    Gullberg, Maria; Lohse, Louise; Bøtner, Anette

    Introduction Foot-and-mouth disease (FMD) remains one of the most economically important infectious diseases of production animals globally. Vaccination can help to control this disease, however, current vaccines based on chemically inactivated FMDV, are imperfect and there is a need for new, safe...... and effective vaccines to control FMD. There is no cross protection between the 7 serotypes but serotype O is the most abundant globally. Material and methods The FMDV capsid protein precursor (P1-2A) of strain O1 Manisa has been expressed with the FMDV 3C protease (3Cpro) using a “single cycle” packaged...... alphavirus self-replicating RNA based on Semliki Forest virus (SFV). Purified O1 Manisa empty capsid particles (ECs) have been prepared using a recombinant vaccinia virus expression system. Cattle have been vaccinated with the SFV-FMDV vectors and boosted subsequently with the ECs and then challenged...

  6. Effect of live attenuated vaccines on the course of experimental allergic encephalomyelitis. A pilot study.

    Science.gov (United States)

    Caspary, E A

    1977-01-01

    The clinical severity of EAE is enhanced by pre-treatment with distemper, measles and BCG vaccine, measles vaccine gives a more severe onset of disease. Rubella vaccine and TAB leads to mild disease which recurs on re-treatment with the appropriate vaccine. These findings and their possible significance in MS are briefly discussed.

  7. Antigenic characterization of a formalin-inactivated poliovirus vaccine derived from live-attenuated Sabin strains.

    Science.gov (United States)

    Tano, Yoshio; Shimizu, Hiroyuki; Martin, Javier; Nishimura, Yorihiro; Simizu, Bunsiti; Miyamura, Tatsuo

    2007-10-10

    A candidate inactivated poliovirus vaccine derived from live-attenuated Sabin strains (sIPV), which are used in the oral poliovirus vaccine (OPV), was prepared in a large-production scale. The modification of viral antigenic epitopes during the formalin inactivation process was investigated by capture ELISA assays using type-specific and antigenic site-specific monoclonal antibodies (MoAbs). The major antigenic site 1 was modified during the formalin inactivation of Sabin 1. Antigenic sites 1-3 were slightly modified during the formalin inactivation of Sabin 2 strain. Sites 1 and 3 were altered on inactivated Sabin 3 virus. These alterations were different to those shown by wild-type Saukett strain, used in conventional IPV (cIPV). It has been previously reported that type 1 sIPV showed higher immunogenicity to type 1 cIPV whereas types 2 and 3 sIPV induced lower level of immunogenicity than their cIPV counterparts. Our results suggest that the differences in epitope structure after formalin inactivation may account, at least in part, for the observed differences in immunogenicity between Sabin and wild-type inactivated poliovaccines.

  8. The control of East Coast fever of cattle by live parasite vaccination: A science-to-impact narrative

    Directory of Open Access Journals (Sweden)

    B.D. Perry

    2016-12-01

    Full Text Available There is an increasing interest in determining the impact of vaccine technologies developed using public funding targeted at international development, and understanding the factors and ingredients which contribute to the success and impacts of such vaccines. This paper chronicles the development of a live vaccine against East Coast fever, a tick-borne disease of cattle caused by Theileria parva. The paper describes the technological innovation, commonly known as infection-and-treatment, which was developed some 40 years ago, explores the institutional settings in which the vaccine was developed and refined, and discusses the political dynamics of both during the decades from first development to field deployment and impacts. The paper also analyses the direct and indirect indicators of success of ITM and the many qualifiers of these, the impacts that the emerging technology has had, both in positive and negative terms, and maps the key contributors and milestones on the research-to-impact pathway.

  9. Multiple antigens of Yersinia pestis delivered by live recombinant attenuated Salmonella vaccine strains elicit protective immunity against plague.

    Science.gov (United States)

    Sanapala, Shilpa; Rahav, Hannah; Patel, Hetal; Sun, Wei; Curtiss, Roy

    2016-05-05

    Based on our improved novel Salmonella vaccine delivery platform, we optimized the recombinant attenuated Salmonella typhimurium vaccine (RASV) χ12094 to deliver multiple Yersinia pestis antigens. These included LcrV196 (amino acids, 131-326), Psn encoded on pYA5383 and F1 encoded in the chromosome, their synthesis did not cause adverse effects on bacterial growth. Oral immunization with χ12094(pYA5383) simultaneously stimulated high antibody titers to LcrV, Psn and F1 in mice and presented complete protection against both subcutaneous (s.c.) and intranasal (i.n.) challenges with high lethal doses of Y. pestis CO92. Moreover, no deaths or other disease symptoms were observed in SCID mice orally immunized with χ12094(pYA5383) over a 60-day period. Therefore, the trivalent S. typhimurium-based live vaccine shows promise for a next-generation plague vaccine. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Memory T-cell immune response in healthy young adults vaccinated with live attenuated influenza A (H5N2) vaccine.

    Science.gov (United States)

    Chirkova, T V; Naykhin, A N; Petukhova, G D; Korenkov, D A; Donina, S A; Mironov, A N; Rudenko, L G

    2011-10-01

    Cellular immune responses of both CD4 and CD8 memory/effector T cells were evaluated in healthy young adults who received two doses of live attenuated influenza A (H5N2) vaccine. The vaccine was developed by reassortment of nonpathogenic avian A/Duck/Potsdam/1402-6/68 (H5N2) and cold-adapted A/Leningrad/134/17/57 (H2N2) viruses. T-cell responses were measured by standard methods of intracellular cytokine staining of gamma interferon (IFN-γ)-producing cells and a novel T-cell recognition of antigen-presenting cells by protein capture (TRAP) assay based on the trogocytosis phenomenon, namely, plasma membrane exchange between interacting immune cells. TRAP enables the detection of activated trogocytosis-positive T cells after virus stimulation. We showed that two doses of live attenuated influenza A (H5N2) vaccine promoted both CD4 and CD8 T-memory-cell responses in peripheral blood of healthy young subjects in the clinical study. Significant differences in geometric mean titers (GMTs) of influenza A (H5N2)-specific IFN-γ(+) cells were observed at day 42 following the second vaccination, while peak levels of trogocytosis(+) T cells were detected earlier, on the 21st day after the second vaccination. The inverse correlation of baseline levels compared to postvaccine fold changes in GMTs of influenza-specific CD4 and CD8 T cells demonstrated that baseline levels of these specific cells could be considered a predictive factor of vaccine immunogenicity.

  11. Screening for viral extraneous agents in live-attenuated avian vaccines by using a microbial microarray and sequencing

    DEFF Research Database (Denmark)

    Olesen, Majken Lindholm; Jørgensen, Lotte Leick; Blixenkrone-Møller, Merete

    2018-01-01

    The absence of extraneous agents (EA) in the raw material used for production and in finished products is one of the principal safety elements related to all medicinal products of biological origin, such as live-attenuated vaccines. The aim of this study was to investigate the applicability...... of the Lawrence Livermore Microbial detection array version 2 (LLMDAv2) combined with whole genome amplification and sequencing for screening for viral EAs in live-attenuated vaccines and specific pathogen-free (SPF) eggs.We detected positive microarray signals for avian endogenous retrovirus EAV-HP and several...... viruses belonging to the Alpharetrovirus genus in all analyzed vaccines and SPF eggs. We used a microarray probe mapping approach to evaluate the presence of intact retroviral genomes, which in addition to PCR analysis revealed that several of the positive microarray signals were most likely due to cross...

  12. Intestinal parasites and vector-borne pathogens in stray and free-roaming cats living in continental and insular Greece

    Science.gov (United States)

    Diakou, Anastasia; Di Cesare, Angela; Accettura, Paolo Matteo; Barros, Luciano; Iorio, Raffaella; Paoletti, Barbara; Frangipane di Regalbono, Antonio; Halos, Lénaïg; Beugnet, Frederic; Traversa, Donato

    2017-01-01

    This survey investigated the distribution of various intestinal parasites and vector-borne pathogens in stray and free-roaming cats living in four regions of Greece. A total number of one hundred and fifty cats living in three Islands (Crete, Mykonos and Skopelos) and in Athens municipality was established as a realistic aim to be accomplished in the study areas. All cats were examined with different microscopic, serological and molecular assays aiming at evaluating the occurrence of intestinal parasites, and exposure to or presence of vector-borne infections. A total of 135 cats (90%) was positive for one or more parasites and/or pathogens transmitted by ectoparasites. Forty-four (29.3%) cats were positive for one single infection, while 91 (60.7%) for more than one pathogen. A high number of (n. 53) multiple infections caused by feline intestinal and vector-borne agents including at least one zoonotic pathogen was detected. Among them, the most frequently recorded helminths were roundworms (Toxocara cati, 24%) and Dipylidium caninum (2%), while a high number of examined animals (58.8%) had seroreaction for Bartonella spp., followed by Rickettsia spp. (43.2%) and Leishmania infantum (6.1%). DNA-based assays revealed the zoonotic arthropod-borne organisms Bartonella henselae, Bartonella clarridgeiae, Rickettsia spp., and L. infantum. These results show that free-ranging cats living in areas of Greece under examination may be exposed to a plethora of internal parasites and vector-borne pathogens, some of them potentially able to infect humans. Therefore, epidemiological vigilance and appropriate control measures are crucial for the prevention and control of these infections and to minimize the risk of infection for people. PMID:28141857

  13. Intestinal parasites and vector-borne pathogens in stray and free-roaming cats living in continental and insular Greece.

    Directory of Open Access Journals (Sweden)

    Anastasia Diakou

    2017-01-01

    Full Text Available This survey investigated the distribution of various intestinal parasites and vector-borne pathogens in stray and free-roaming cats living in four regions of Greece. A total number of one hundred and fifty cats living in three Islands (Crete, Mykonos and Skopelos and in Athens municipality was established as a realistic aim to be accomplished in the study areas. All cats were examined with different microscopic, serological and molecular assays aiming at evaluating the occurrence of intestinal parasites, and exposure to or presence of vector-borne infections. A total of 135 cats (90% was positive for one or more parasites and/or pathogens transmitted by ectoparasites. Forty-four (29.3% cats were positive for one single infection, while 91 (60.7% for more than one pathogen. A high number of (n. 53 multiple infections caused by feline intestinal and vector-borne agents including at least one zoonotic pathogen was detected. Among them, the most frequently recorded helminths were roundworms (Toxocara cati, 24% and Dipylidium caninum (2%, while a high number of examined animals (58.8% had seroreaction for Bartonella spp., followed by Rickettsia spp. (43.2% and Leishmania infantum (6.1%. DNA-based assays revealed the zoonotic arthropod-borne organisms Bartonella henselae, Bartonella clarridgeiae, Rickettsia spp., and L. infantum. These results show that free-ranging cats living in areas of Greece under examination may be exposed to a plethora of internal parasites and vector-borne pathogens, some of them potentially able to infect humans. Therefore, epidemiological vigilance and appropriate control measures are crucial for the prevention and control of these infections and to minimize the risk of infection for people.

  14. Intestinal parasites and vector-borne pathogens in stray and free-roaming cats living in continental and insular Greece.

    Science.gov (United States)

    Diakou, Anastasia; Di Cesare, Angela; Accettura, Paolo Matteo; Barros, Luciano; Iorio, Raffaella; Paoletti, Barbara; Frangipane di Regalbono, Antonio; Halos, Lénaïg; Beugnet, Frederic; Traversa, Donato

    2017-01-01

    This survey investigated the distribution of various intestinal parasites and vector-borne pathogens in stray and free-roaming cats living in four regions of Greece. A total number of one hundred and fifty cats living in three Islands (Crete, Mykonos and Skopelos) and in Athens municipality was established as a realistic aim to be accomplished in the study areas. All cats were examined with different microscopic, serological and molecular assays aiming at evaluating the occurrence of intestinal parasites, and exposure to or presence of vector-borne infections. A total of 135 cats (90%) was positive for one or more parasites and/or pathogens transmitted by ectoparasites. Forty-four (29.3%) cats were positive for one single infection, while 91 (60.7%) for more than one pathogen. A high number of (n. 53) multiple infections caused by feline intestinal and vector-borne agents including at least one zoonotic pathogen was detected. Among them, the most frequently recorded helminths were roundworms (Toxocara cati, 24%) and Dipylidium caninum (2%), while a high number of examined animals (58.8%) had seroreaction for Bartonella spp., followed by Rickettsia spp. (43.2%) and Leishmania infantum (6.1%). DNA-based assays revealed the zoonotic arthropod-borne organisms Bartonella henselae, Bartonella clarridgeiae, Rickettsia spp., and L. infantum. These results show that free-ranging cats living in areas of Greece under examination may be exposed to a plethora of internal parasites and vector-borne pathogens, some of them potentially able to infect humans. Therefore, epidemiological vigilance and appropriate control measures are crucial for the prevention and control of these infections and to minimize the risk of infection for people.

  15. Establishment of human sperm-specific voltage-dependent anion channel 3 recombinant vector for the production of a male contraceptive vaccine

    Directory of Open Access Journals (Sweden)

    Asmarinah Asmarinah

    2012-05-01

    Full Text Available Background: The aim of this study was to construct a recombinant vector of human sperm specific VDAC3 gene for production of VDAC3 antibody, which is potential as male contraception vaccine.Methods: Target fragment sequence of VDAC3 gene was obtained through amplification of human sperm VDAC3 cDNA with primers covering exon 5 to exon 8. Its PCR product in size of 435 bp was cloned to the pET101/D-TOPO expression vector (5753 bp. E. coli bacteria were transformed with this vector. Cloning of VDAC3 fragment gene to the vector was confirmed by the using of XbaI restriction enzyme and PCR colony method with primers covering exons 5-8 of the human VDAC3 gene.Results: Alignment analysis of amplified fragment covering exon 5 to exon 8 of VDAC3 gene showed 94% homology to human VDAC3 gene from databank. After cloning to the expression vector and transformation to E. coli competent cells, twelve colonies could grow in culture media. Gel electrophoresis of sliced VDAC3 recombinant vector showed a single band in the size of 6181 bp in 8 colonies. After application of PCR colony and amplicon sequencing, the result showed a single band in the size of 435 bp and fragment sequence with 94% identity to human VDAC3 gene.Conclusion: The construction of human sperm specific VDAC3 gene recombinant vector was established in this study. In the future, this recombinant vector will be used to produce VDAC3 antibody for the development of a male contraception vaccine. (Med J Indones. 2012;21:61-5Keywords: Contraception, recombinant vector, sperm, VDAC3

  16. Vaccination elicits a prominent acute phase response in horses.

    Science.gov (United States)

    Andersen, Susanne A; Petersen, Henrik H; Ersbøll, Annette K; Falk-Rønne, Jørgen; Jacobsen, Stine

    2012-02-01

    European and American guidelines for vaccination against tetanus and influenza in horses recommend annual and annual/semi-annual vaccinations, respectively, against the two pathogens. Too-frequent vaccination may, however, have adverse effects, among other things because an inflammatory response is elicited with subsequent alterations in homeostasis. The objective of the study was to compare the acute phase response (APR) in 10 horses following administration of two different types of vaccines, namely, an inactivated Immune Stimulating COMplex (ISCOM) vaccine and a live recombinant vector vaccine. Blood was sampled before and after vaccination to measure levels of serum amyloid A (SAA), fibrinogen, white blood cell counts (WBC) and iron. Vaccination induced a prominent APR with increased WBC, elevated blood levels of SAA and fibrinogen, and decreased serum iron concentrations. The ISCOM vaccine caused significantly (Phorse owners about convalescence after vaccination. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Safety and tolerability of a live oral Salmonella typhimurium vaccine candidate in SIV-infected nonhuman primates.

    Science.gov (United States)

    Ault, Alida; Tennant, Sharon M; Gorres, J Patrick; Eckhaus, Michael; Sandler, Netanya G; Roque, Annelys; Livio, Sofie; Bao, Saran; Foulds, Kathryn E; Kao, Shing-Fen; Roederer, Mario; Schmidlein, Patrick; Boyd, Mary Adetinuke; Pasetti, Marcela F; Douek, Daniel C; Estes, Jacob D; Nabel, Gary J; Levine, Myron M; Rao, Srinivas S

    2013-12-02

    Nontyphoidal Salmonella (NTS) serovars are a common cause of acute food-borne gastroenteritis worldwide and can cause invasive systemic disease in young infants, the elderly, and immunocompromised hosts, accompanied by high case fatality. Vaccination against invasive NTS disease is warranted where the disease incidence and mortality are high and multidrug resistance is prevalent, as in sub-Saharan Africa. Live-attenuated vaccines that mimic natural infection constitute one strategy to elicit protection. However, they must particularly be shown to be adequately attenuated for consideration of immunocompromised subjects. Accordingly, we examined the safety and tolerability of an oral live attenuated Salmonella typhimurium vaccine candidate, CVD 1921, in an established chronic simian immunodeficiency virus (SIV)-infected rhesus macaque model. We evaluated clinical parameters, histopathology, and measured differences in mucosal permeability to wild-type and vaccine strains. Compared to the wild-type S. typhimurium strain I77 in both SIV-infected and SIV-uninfected nonhuman primate hosts, this live-attenuated vaccine shows reduced shedding and systemic spread, exhibits limited pathological disease manifestations in the digestive tract, and induces low levels of cellular infiltration in tissues. Furthermore, wild-type S. typhimurium induces increased intestinal epithelial damage and permeability, with infiltration of neutrophils and macrophages in both SIV-infected and SIV-uninfected nonhuman primates compared to the vaccine strain. Based on shedding, systemic spread, and histopathology, the live-attenuated S. typhimurium strain CVD 1921 appears to be safe and well-tolerated in the nonhuman primate model, including chronically SIV-infected rhesus macaques. Copyright © 2013. Published by Elsevier Ltd.

  18. Multimodality imaging of reporter gene expression using a novel fusion vector in living cells and animals

    Science.gov (United States)

    Gambhir, Sanjiv [Portola Valley, CA; Pritha, Ray [Mountain View, CA

    2011-06-07

    Novel double and triple fusion reporter gene constructs harboring distinct imagable reporter genes are provided, as well as applications for the use of such double and triple fusion constructs in living cells and in living animals using distinct imaging technologies.

  19. Serologic response of SPF chickens to live vaccines and other strains of Mycoplasma gallisepticum

    Directory of Open Access Journals (Sweden)

    ER do Nascimento

    2006-03-01

    Full Text Available False positive serologic reactions and difficulties in the diagnosis of Mycoplasma gallisepticum (MG in chickens have increased lately as a result of infection by low virulent MG strains and the use of live MG vaccines in poultry. The objective of this study was to evaluate the serologic responses of SPF chickens exposed to the three commercially available live MG vaccines, and one low virulent MG strain (MG-70, contributing to the diagnosis and monitoring of MG infection in birds. Six groups of SPF chickens were used. The control group was not infected nor challenged; one group was infected with the low virulent strain MG-70 (MG-70; three groups were immunized and named after the MG vaccine used, i.e., MG-6/85, MG-ts11, and MG-F; and finally one group was infected with the virulent MG standard strain, MGR. Random Amplification of Polymorphic DNA (RAPDPCR was used to compare the strains to each other, to the standard MG-A5969, and to MGR. All strains were found to be genetically distinguishable from each other. Birds in the control group showed negative results throughout the experiment and showed no cross-reaction with M. synoviae in any serologic test. ELISA tests at 21 days post first exposure (P1E and seven days after the second exposure (P2E, evidenced that 25% of the MG70 birds were positive, whereas vaccine groups yielded higher positivity rate, i.e., 57%, 43% and 29% for MG-6/85, MG-ts11 and MG-F, respectively. Serum plate agglutination (SPA evidenced the first positive results at 35 days P1E on birds in the MG-F group at the rate of 100%; followed by 40% of birds in the MG-70 group at 63 days P1E. Chickens in MG-ts11 and MG 6/85 groups had identical behavior and yielded 100% positive SPA at 77 days P1E. In regard to hemagglutination inhibition (HI, 14 % of the birds in MG-F and MG-ts11 reacted at 42 days P1E, while MG-70 and MG-6/85 groups yielded positive results only after challenge; MG-70 birds reacted at 56 days P1E at the rate of

  20. A new adenovirus based vaccine vector expressing an Eimeria tenella derived TLR agonist improves cellular immune responses to an antigenic target.

    Directory of Open Access Journals (Sweden)

    Daniel M Appledorn

    2010-03-01

    Full Text Available Adenoviral based vectors remain promising vaccine platforms for use against numerous pathogens, including HIV. Recent vaccine trials utilizing Adenovirus based vaccines expressing HIV antigens confirmed induction of cellular immune responses, but these responses failed to prevent HIV infections in vaccinees. This illustrates the need to develop vaccine formulations capable of generating more potent T-cell responses to HIV antigens, such as HIV-Gag, since robust immune responses to this antigen correlate with improved outcomes in long-term non-progressor HIV infected individuals.In this study we designed a novel vaccine strategy utilizing an Ad-based vector expressing a potent TLR agonist derived from Eimeria tenella as an adjuvant to improve immune responses from a [E1-]Ad-based HIV-Gag vaccine. Our results confirm that expression of rEA elicits significantly increased TLR mediated innate immune responses as measured by the influx of plasma cytokines and chemokines, and activation of innate immune responding cells. Furthermore, our data show that the quantity and quality of HIV-Gag specific CD8(+ and CD8(- T-cell responses were significantly improved when coupled with rEA expression. These responses also correlated with a significantly increased number of HIV-Gag derived epitopes being recognized by host T cells. Finally, functional assays confirmed that rEA expression significantly improved antigen specific CTL responses, in vivo. Moreover, we show that these improved responses were dependent upon improved TLR pathway interactions.The data presented in this study illustrate the potential utility of Ad-based vectors expressing TLR agonists to improve clinical outcomes dependent upon induction of robust, antigen specific immune responses.

  1. Expression of chicken parvovirus VP2 in chicken embryo fibroblasts requires codon optimization for production of naked DNA and vectored meleagrid herpesvirus type 1 vaccines.

    Science.gov (United States)

    Spatz, Stephen J; Volkening, Jeremy D; Mullis, Robert; Li, Fenglan; Mercado, John; Zsak, Laszlo

    2013-10-01

    Meleagrid herpesvirus type 1 (MeHV-1) is an ideal vector for the expression of antigens from pathogenic avian organisms in order to generate vaccines. Chicken parvovirus (ChPV) is a widespread infectious virus that causes serious disease in chickens. It is one of the etiological agents largely suspected in causing Runting Stunting Syndrome (RSS) in chickens. Initial attempts to express the wild-type gene encoding the capsid protein VP2 of ChPV by insertion into the thymidine kinase gene of MeHV-1 were unsuccessful. However, transient expression of a codon-optimized synthetic VP2 gene cloned into the bicistronic vector pIRES2-Ds-Red2, could be demonstrated by immunocytochemical staining of transfected chicken embryo fibroblasts (CEFs). Red fluorescence could also be detected in these transfected cells since the red fluorescent protein gene is downstream from the internal ribosome entry site (IRES). Strikingly, fluorescence could not be demonstrated in cells transiently transfected with the bicistronic vector containing the wild-type or non-codon-optimized VP2 gene. Immunocytochemical staining of these cells also failed to demonstrate expression of wild-type VP2, indicating that the lack of expression was at the RNA level and the VP2 protein was not toxic to CEFs. Chickens vaccinated with a DNA vaccine consisting of the bicistronic vector containing the codon-optimized VP2 elicited a humoral immune response as measured by a VP2-specific ELISA. This VP2 codon-optimized bicistronic cassette was rescued into the MeHV-1 genome generating a vectored vaccine against ChPV disease.

  2. Simultaneous subcutaneous and conjunctival administration of the influenza viral vector based Brucella abortus vaccine to pregnant heifers provides better protection against B. abortus 544 infection than the commercial B. abortus S19 vaccine.

    Science.gov (United States)

    Tabynov, Kaissar; Orynbayev, Mukhit; Renukaradhya, Gourapura J; Sansyzbay, Abylai

    2016-09-30

    In this study, we explored possibility of increasing the protective efficacy of our novel influenza viral vector based B. abortus vaccine (Flu-BA) in pregnant heifers by adapting an innovative method of vaccine delivery. We administered the vaccine concurrently via the conjunctival and subcutaneous routes to pregnant heifers, and these routes were previously tested individually. The Flu-BA vaccination of pregnant heifers (n=9) against a challenge B. abortus 544 infection provided protection from abortion, infection of heifers and fetuses/calves by 88.8%, 100% and 100%, respectively (alpha=0.004-0.0007 vs. negative control; n=7). Our candidate vaccine using this delivery method provided slightly better protection than the commercial B. abortus S19 vaccine in pregnant heifers (n=8), which provided protection from abortion, infection of heifers and fetuses/calves by 87.5%, 75% and 87.5%, respectively. This improved method of the Flu-BA vaccine administration is highly recommended for the recovery of farms which has high prevalence of brucellosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Live Vaccine Strain Francisella tularensis is Detectable at the Inoculation Site but Not in Blood after Vaccination Against Tularemia

    National Research Council Canada - National Science Library

    Hepburn, Matthew J; Purcell, Bret K; Lawler, James V; Coyne, Susan R; Petitt, Patricia L; Sellers, Karen D; Norwood, David A; Ulrich, Melanie P

    2006-01-01

    ...) for the detection of F. tularensis in human clinical samples. Methods. Blood and skin swab samples were prospectively collected from volunteers who received the LVS tularemia vaccine at baseline (negative controls...

  4. Improving Mycobacterium bovis Bacillus Calmette-Guèrin as a Vaccine Delivery Vector for Viral Antigens by Incorporation of Glycolipid Activators of NKT Cells

    OpenAIRE

    Venkataswamy, Manjunatha M.; Ng, Tony W.; Kharkwal, Shalu S.; Carreño, Leandro J.; Johnson, Alison J.; Kunnath-Velayudhan, Shajo; Liu, Zheng; Bittman, Robert; Jervis, Peter J.; Cox, Liam R.; Besra, Gurdyal S.; Wen, Xiangshu; Yuan, Weiming; Tsuji, Moriya; Li, Xiangming

    2014-01-01

    Recombinant Mycobacterium bovis bacillus Calmette-Guèrin (rBCG) has been explored as a vector for vaccines against HIV because of its ability to induce long lasting humoral and cell mediated immune responses. To maximize the potential for rBCG vaccines to induce effective immunity against HIV, various strategies are being employed to improve its ability to prime CD8+ T cells, which play an important role in the control of HIV infections. In this study we adopted a previously described approac...

  5. Heterologous Two-Dose Vaccination with Simian Adenovirus and Poxvirus Vectors Elicits Long-Lasting Cellular Immunity to Influenza Virus A in Healthy Adults

    Directory of Open Access Journals (Sweden)

    L. Coughlan

    2018-03-01

    Full Text Available Background: T-cell responses against highly conserved influenza antigens have been previously associated with protection. However, these immune responses are poorly maintained following recovery from influenza infection and are not boosted by inactivated influenza vaccines. We have previously demonstrated the safety and immunogenicity of two viral vectored vaccines, modified vaccinia virus Ankara (MVA and the chimpanzee adenovirus ChAdOx1 expressing conserved influenza virus antigens, nucleoprotein (NP and matrix protein-1 (M1. We now report on the safety and long-term immunogenicity of multiple combination regimes of these vaccines in young and older adults. Methods: We conducted a Phase I open-label, randomized, multi-center study in 49 subjects aged 18–46 years and 24 subjects aged 50 years or over. Following vaccination, adverse events were recorded and the kinetics of the T cell response determined at multiple time points for up to 18 months. Findings: Both vaccines were well tolerated. A two dose heterologous vaccination regimen significantly increased the magnitude of pre-existing T-cell responses to NP and M1 after both doses in young and older adults. The fold-increase and peak immune responses after a single MVA-NP + M1 vaccination was significantly higher compared to ChAdOx1 NP + M1. In a mixed regression model, T-cell responses over 18 months were significantly higher following the two dose vaccination regimen of MVA/ChAdOx1 NP + M1. Interpretation: A two dose heterologous vaccination regimen of MVA/ChAdOx1 NP + M1 was safe and immunogenic in young and older adults, offering a promising vaccination strategy for inducing long-term broadly cross-reactive protection against influenza A. Funding Source: Medical Research Council UK, NIHR BMRC Oxford. Keywords: Influenza, T-cell responses, Influenza vaccines, Viral vectors, Adults, Older adults

  6. Recombinant lactic acid bacteria as delivery vectors of heterologous antigens: the future of vaccination?

    Science.gov (United States)

    Trombert, A

    2015-01-01

    Lactic acid bacteria (LABs) are good candidates for the development of new oral vaccines and are attractive alternatives to attenuated pathogens. This review focuses on the use of wild-type and recombinant lactococci and lactobacilli with emphasis on their molecular design, immunomodulation and treatment of bacterial infections. The majority of studies related to recombinant LABs have focused on Lactococcus lactis, however, molecular tools have been successfully used for Lactobacillus spp. Recombinant lactobacilli and lactococci have several health benefits, such as immunomodulation, restoration of the microbiota, synthesis of antimicrobial substances and inhibition of virulence factors. In addition, protective immune responses that are well tolerated are induced by the expression of heterologous antigens from recombinant probiotics.

  7. Questions regarding the safety and duration of immunity following live yellow fever vaccination.

    Science.gov (United States)

    Amanna, Ian J; Slifka, Mark K

    2016-12-01

    The World Health Organization (WHO) and other health agencies have concluded that yellow fever booster vaccination is unnecessary since a single dose of vaccine confers lifelong immunity. Areas covered: We reviewed the clinical studies cited by health authorities in their investigation of both the safety profile and duration of immunity for the YFV-17D vaccine and examined the position that booster vaccination is no longer needed. We found that antiviral immunity may be lost in 1-in-3 to 1-in-5 individuals within 5 to 10 years after a single vaccination and that children may be at greater risk for primary vaccine failure. The safety profile of YFV-17D was compared to other licensed vaccines including oral polio vaccine (OPV) and the rotavirus vaccine, RotaShield, which have subsequently been withdrawn from the US and world market, respectively. Expert commentary: Based on these results and recent epidemiological data on vaccine failures (particularly evident at >10 years after vaccination), we believe that current recommendations to no longer administer YFV-17D booster vaccination be carefully re-evaluated, and that further development of safer vaccine approaches should be considered.

  8. Questions regarding the safety and duration of immunity following live yellow fever vaccination

    Science.gov (United States)

    Amanna, Ian J.; Slifka, Mark K.

    2016-01-01

    Introduction The World Health Organization (WHO) and other health agencies have concluded that yellow fever booster vaccination is unnecessary since a single dose of vaccine confers lifelong immunity. Areas Covered We reviewed the clinical studies cited by health authorities in their investigation of both the safety profile and duration of immunity for the YFV-17D vaccine and examined the position that booster vaccination is no longer needed. We found that antiviral immunity may be lost in 1-in-3 to 1-in-5 individuals within 5 to 10 years after a single vaccination and that children may be at greater risk for primary vaccine failure. The safety profile of YFV-17D was compared to other licensed vaccines including oral polio vaccine (OPV) and the rotavirus vaccine, RotaShield, which have subsequently been withdrawn from the US and world market, respectively. Expert Commentary Based on these results and recent epidemiological data on vaccine failures (particularly evident at >10 years after vaccination), we believe that current recommendations to no longer administer YFV-17D booster vaccination be carefully re-evaluated, and that further development of safer vaccine approaches should be considered. PMID:27267203

  9. Public health impact and cost effectiveness of mass vaccination with live attenuated human rotavirus vaccine (RIX4414) in India: model based analysis.

    Science.gov (United States)

    Rose, Johnie; Hawthorn, Rachael L; Watts, Brook; Singer, Mendel E

    2009-09-25

    To examine the public health impact of mass vaccination with live attenuated human rotavirus vaccine (RIX4414) in a birth cohort in India, and to estimate the cost effectiveness and affordability of such a programme. Decision analytical Markov model encompassing all direct medical costs. Infection risk and severity depended on age, number of previous infections, and vaccination history; probabilities of use of inpatient and outpatient health services depended on symptom severity. Published clinical, epidemiological, and economic data. When possible, parameter estimates were based on data specific for India. Population Simulated Indian birth cohort followed for five years. Decrease in rotavirus gastroenteritis episodes (non-severe and severe), deaths, outpatient visits, and admission to hospital; incremental cost effectiveness ratio of vaccination expressed as net cost in 2007 rupees per life year saved. In the base case, vaccination prevented 28,943 (29.7%) symptomatic episodes, 6981 (38.2%) severe episodes, 164 deaths (41.0%), 7178 (33.3%) outpatient visits, and 812 (34.3%) admissions to hospital per 100,000 children. Vaccination cost 8023 rupees (about pound100, euro113, $165) per life year saved, less than India's per capita gross domestic product, a common criterion for cost effectiveness. The net programme cost would be equivalent to 11.6% of the 2006-7 budget of the Indian Department of Health and Family Welfare. Model results were most sensitive to variations in access to outpatient care for those with severe symptoms. If this parameter was increased to its upper limit, the incremental cost effectiveness ratio for vaccination still fell between one and three times the per capita gross domestic product, meeting the World Health Organization's criterion for "cost effective" interventions. Uncertainty analysis indicated a 94.7% probability that vaccination would be cost effective according to a criterion of one times per capita gross domestic product per life

  10. Evaluation of synthetic infection-enhancing lipopeptides as adjuvants for a live-attenuated canine distemper virus vaccine administered intra-nasally to ferrets.

    Science.gov (United States)

    Nguyen, D Tien; Ludlow, Martin; van Amerongen, Geert; de Vries, Rory D; Yüksel, Selma; Verburgh, R Joyce; Osterhaus, Albert D M E; Duprex, W Paul; de Swart, Rik L

    2012-07-20

    Inactivated paramyxovirus vaccines have been associated with hypersensitivity responses upon challenge infection. For measles and canine distemper virus (CDV) safe and effective live-attenuated virus vaccines are available, but for human respiratory syncytial virus and human metapneumovirus development of such vaccines has proven difficult. We recently identified three synthetic bacterial lipopeptides that enhance paramyxovirus infections in vitro, and hypothesized these could be used as adjuvants to promote immune responses induced by live-attenuated paramyxovirus vaccines. Here, we tested this hypothesis using a CDV vaccination and challenge model in ferrets. Three groups of six animals were intra-nasally vaccinated with recombinant (r) CDV(5804P)L(CCEGFPC) in the presence or absence of the infection-enhancing lipopeptides Pam3CSK4 or PHCSK4. The recombinant CDV vaccine virus had previously been described to be over-attenuated in ferrets. A group of six animals was mock-vaccinated as control. Six weeks after vaccination all animals were challenged with a lethal dose of rCDV strain Snyder-Hill expressing the red fluorescent protein dTomato. Unexpectedly, intra-nasal vaccination of ferrets with rCDV(5804P)L(CCEGFPC) in the absence of lipopeptides resulted in good immune responses and protection against lethal challenge infection. However, in animals vaccinated with lipopeptide-adjuvanted virus significantly higher vaccine virus loads were detected in nasopharyngeal lavages and peripheral blood mononuclear cells. In addition, these animals developed significantly higher CDV neutralizing antibody titers compared to animals vaccinated with non-adjuvanted vaccine. This study demonstrates that the synthetic cationic lipopeptides Pam3CSK4 and PHCSK4 not only enhance paramyxovirus infection in vitro, but also in vivo. Given the observed enhancement of immunogenicity their potential as adjuvants for other live-attenuated paramyxovirus vaccines should be considered

  11. Development of live attenuated Streptococcus agalactiae vaccine for tilapia via continuous passage in vitro.

    Science.gov (United States)

    Li, L P; Wang, R; Liang, W W; Huang, T; Huang, Y; Luo, F G; Lei, A Y; Chen, M; Gan, X

    2015-08-01

    Fish Streptococcus agalactiae (S. agalactiae) seriously harms the world's aquaculture industry and causes huge economic losses. This study aimed to develop a potential live attenuated vaccine of S. agalactiae. Pre-screened vaccine candidate strain S. agalactiae HN016 was used as starting material to generate an attenuated strain S. agalactiae YM001 by continuous passage in vitro. The biological characteristics, virulence, and stability of YM001 were detected, and the protective efficacy of YM001 immunization in tilapia was also determined. Our results indicated that the growth, staining, characteristics of pulsed-field gel electrophoresis (PFGE) genotype, and virulence of YM001 were changed significantly as compared to the parental strain HN016. High doses of YM001 by intraperitoneal (IP) injection (1.0 × 10(9) CFU/fish) and oral gavage (1.0 × 10(10) CFU/fish) respectively did not cause any mortality and morbidity in tilapia. The relative percent survivals (RPSs) of fishes immunized with YM001 (1.0 × 10(8) CFU/fish, one time) via injection, immersion, and oral administration were 96.88, 67.22, and 71.81%, respectively, at 15 days, and 93.61, 60.56, and 53.16%, respectively, at 30 days. In all tests with 1-3 times of immunization in tilapia, the dosages at 1 × 10(8) and 1 × 10(9) CFU/fish displayed the similar best results, whereas the immunoprotection of the dosages at 1 × 10(6) and 1 × 10(7) CFU/fish declined significantly (P 0.05). The level of protective antibody elicited by oral immunization was significantly higher compared to that of the control group (P S. agalactiae strain YM001; oral immunization of tilapia with this strain produced a good immune protection. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Live vaccine against measles, mumps, and rubella and the risk of hospital admissions for nontargeted infections

    DEFF Research Database (Denmark)

    Sørup, Signe; Benn, Christine Stabell; Poulsen, Anja

    2014-01-01

    ). Nationwide Danish registers provided data on vaccinations and hospital admissions. The recommended vaccination schedule was inactivated vaccine against diphtheria, tetanus, pertussis, polio, and Haemophilus influenzae type b (DTaP-IPV-Hib) administered at ages 3, 5, and 12 months and MMR at age 15 months...

  13. 9 CFR 113.71 - Chlamydia Psittaci Vaccine (Feline Pneumonitis), Live Chlamydia.

    Science.gov (United States)

    2010-01-01

    ... titer using the titration method used in paragraph (b)(2) of this section. To be eligible for release... used as vaccinates shall be administered a predetermined quantity of vaccine by the method to be... calculations, five replicate titrations shall be conducted on a sample of the vaccine dilution used. If two...

  14. Classical Swine Fever Outbreak after Modified Live LOM Strain Vaccination in Naive Pigs, South Korea

    Science.gov (United States)

    Je, Sang H.; Kwon, Taeyong; Yoo, Sung J.; Lee, Dong-Uk; Lee, SeungYoon; Richt, Juergen A.

    2018-01-01

    We report classical swine fever outbreaks occurring in naive pig herds on Jeju Island, South Korea, after the introduction of the LOM vaccine strain. Two isolates from sick pigs had >99% identity with the vaccine stain. LOM strain does not appear safe; its use in the vaccine should be reconsidered. PMID:29553332

  15. Construction and evaluation of Bordetella pertussis live attenuated vaccine strain BPZE1 producing Fim3.

    NARCIS (Netherlands)

    Debrie, Anne-Sophie; Coutte, Loïc; Raze, Dominique; Mooi, Frits; Alexander, Frances; Gorringe, Andrew; Mielcarek, Nathalie; Locht, Camille

    2018-01-01

    Pertussis or whooping cough is currently the most prevalent vaccine-preventable childhood disease despite >85% global vaccination coverage. In recent years incidence has greatly increased in several high-income countries that have switched from the first-generation, whole-cell vaccine to the newer

  16. Ad35 and ad26 vaccine vectors induce potent and cross-reactive antibody and T-cell responses to multiple filovirus species.

    Directory of Open Access Journals (Sweden)

    Roland Zahn

    Full Text Available Filoviruses cause sporadic but highly lethal outbreaks of hemorrhagic fever in Africa in the human population. Currently, no drug or vaccine is available for treatment or prevention. A previous study with a vaccine candidate based on the low seroprevalent adenoviruses 26 and 35 (Ad26 and Ad35 was shown to provide protection against homologous Ebola Zaire challenge in non human primates (NHP if applied in a prime-boost regimen. Here we have aimed to expand this principle to construct and evaluate Ad26 and Ad35 vectors for development of a vaccine to provide universal filovirus protection against all highly lethal strains that have caused major outbreaks in the past. We have therefore performed a phylogenetic analysis of filovirus glycoproteins to select the glycoproteins from two Ebola species (Ebola Zaire and Ebola Sudan/Gulu,, two Marburg strains (Marburg Angola and Marburg Ravn and added the more distant non-lethal Ebola Ivory Coast species for broadest coverage. Ad26 and Ad35 vectors expressing these five filovirus glycoproteins were evaluated to induce a potent cellular and humoral immune response in mice. All adenoviral vectors induced a humoral immune response after single vaccination in a dose dependent manner that was cross-reactive within the Ebola and Marburg lineages. In addition, both strain-specific as well as cross-reactive T cell responses could be detected. A heterologous Ad26-Ad35 prime-boost regime enhanced mainly the humoral and to a lower extend the cellular immune response against the transgene. Combination of the five selected filovirus glycoproteins in one multivalent vaccine potentially elicits protective immunity in man against all major filovirus strains that have caused lethal outbreaks in the last 20 years.

  17. [VACCINES].

    Science.gov (United States)

    Bellver Capella, Vincente

    2015-10-01

    Vaccines are an extraordinary instrument of immunization of the population against infectious diseases. Around them there are many ethical issues. One of the most debated is what to do with certain groups opposition to vaccination of their children. States have managed in different ways the conflict between the duty of vaccination and the refusal to use vaccines: some impose the vaccination and others simply promote it. In this article we deal with which of these two approaches is the most suitable from an ethical and legal point of view. We stand up for the second option, which is the current one in Spain, and we propose some measures which should be kept in mind to improve immunization programs.

  18. Canine Parvovirus (CPV) Vaccination: Comparison of Neutralizing Antibody Responses in Pups after Inoculation with CPV2 or CPV2b Modified Live Virus Vaccine

    Science.gov (United States)

    Pratelli, Annamaria; Cavalli, Alessandra; Martella, Vito; Tempesta, Maria; Decaro, Nicola; Carmichael, Leland Eugene; Buonavoglia, Canio

    2001-01-01

    Canine parvovirus type 2 (CPV2) emerged in 1978 as causative agent of a new disease of dogs. New antigenic variants (biotypes), designated CPV2a and CPV2b, became widespread during 1979 to 1980 and 1984, respectively. At the present time the original CPV2 has disappeared in the dog population and has been replaced by the two new viruses. In the present study the comparison of neutralizing antibody titers in two groups of pups (18 pups in each group) inoculated with CPV2 and CPV2b modified live virus vaccines is reported. Using the hemagglutination inhibition (HI) test, relevant differences between antibody titers, against either the homologous or the heterologous virus, were not constantly observed. Using the neutralization (Nt) test, however, the pups inoculated with CPV2 had antibody titers which were approximately 30 times higher to the homologous virus (mean, 4,732) than to the heterologous virus (CPV2b) (mean, 162). The results of these experiments support two conclusions: (i) the HI test may not always accurately evaluate the true immune status of dogs with respect to CPV, and (ii) dogs inoculated with CPV2 vaccine develop relatively low Nt antibody titers against the heterologous virus (CPV2b). These data may suggest an advantage for new vaccines, considering that most presently licensed vaccines are produced with CPV2, which no longer exists in the dog population. PMID:11329467

  19. Canine parvovirus (CPV) vaccination: comparison of neutralizing antibody responses in pups after inoculation with CPV2 or CPV2b modified live virus vaccine.

    Science.gov (United States)

    Pratelli, A; Cavalli, A; Martella, V; Tempesta, M; Decaro, N; Carmichael, L E; Buonavoglia, C

    2001-05-01

    Canine parvovirus type 2 (CPV2) emerged in 1978 as causative agent of a new disease of dogs. New antigenic variants (biotypes), designated CPV2a and CPV2b, became widespread during 1979 to 1980 and 1984, respectively. At the present time the original CPV2 has disappeared in the dog population and has been replaced by the two new viruses. In the present study the comparison of neutralizing antibody titers in two groups of pups (18 pups in each group) inoculated with CPV2 and CPV2b modified live virus vaccines is reported. Using the hemagglutination inhibition (HI) test, relevant differences between antibody titers, against either the homologous or the heterologous virus, were not constantly observed. Using the neutralization (Nt) test, however, the pups inoculated with CPV2 had antibody titers which were approximately 30 times higher to the homologous virus (mean, 4,732) than to the heterologous virus (CPV2b) (mean, 162). The results of these experiments support two conclusions: (i) the HI test may not always accurately evaluate the true immune status of dogs with respect to CPV, and (ii) dogs inoculated with CPV2 vaccine develop relatively low Nt antibody titers against the heterologous virus (CPV2b). These data may suggest an advantage for new vaccines, considering that most presently licensed vaccines are produced with CPV2, which no longer exists in the dog population.

  20. Cold-adapted live attenuated influenza vaccines developed in Russia: Can they contribute to meeting the needs for influenza control in other countries?

    International Nuclear Information System (INIS)

    Kendal, Alan P.

    1997-01-01

    It is now more than 30 years since the first cold-adapted influenza viruses were developed in Russia as potential live, attenuated vaccines. In the past 15-20 years considerable experience has been gained from Russian and joint Russian-US laboratory and clinical studies with type A monovalent and bivalent vaccines prepared with genetic reassortant viruses derived from one of these cold-adapted viruses in particular, A/Leningrad/134/57. More recent experiences include use of trivalent cold-adapted vaccines with a type B component. The overall high level of safety of individual and combined vaccines in pre-school and school-aged children, with illness reductions in open field trials equivalent to that seen with inactivated vaccines, is such as to suggest that practical measures might now be justified to facilitate expansion of the use of these vaccines to other countries. It is proposed that further experimentation with the Russian cold-adapted live attenuated vaccines should be focused on issues that will relate to the public health perspective, i.e. selection of the single best candidate type A and B vaccines for intense study using as criteria their potential for meeting licensing requirements outside Russia, and documenting the clinical protective efficacy of a single vaccine dose compared to two doses as studied until now. Resolution of these issues is important to ensure that costs for future live vaccine production, control, and utilization will be kept at lowest levels so that expanded use of live vaccines will have maximum cost-benefit and affordability. To guide those interested in these issues, examples are given of populations for whom a licensed live cold-adapted vaccine might be considered, together with indications of extra data needed to fully validate each suggested use

  1. Vaccination with an adenoviral vector encoding the tumor antigen directly linked to invariant chain induces potent CD4(+) T-cell-independent CD8(+) T-cell-mediated tumor control

    DEFF Research Database (Denmark)

    Sorensen, Maria R; Holst, Peter J; Pircher, Hanspeter

    2009-01-01

    of the vaccine antigen to invariant chain (Ii). To evaluate this strategy we used a mouse model, in which an immunodominant epitope (GP33) of the LCMV glycoprotein (GP) represents the tumor-associated neoantigen. Prophylactic vaccination of C57BL/6 mice with a replication-deficient human adenovirus 5 vector...... encoding GP linked to Ii (Ad-Ii-GP) resulted in complete protection against GP33-expressing B16.F10 tumors. Therapeutic vaccination with Ad-Ii-GP delayed tumor growth by more than 2 wk compared with sham vaccination. Notably, therapeutic vaccination with the linked vaccine was significantly better than...... the tumor degradation. Finally, Ad-Ii-GP but not Ad-GP vaccination can break the immunological non-reactivity in GP transgenic mice indicating that our vaccine strategy will prove efficient also against endogenous tumor antigens....

  2. Immunization with a recombinant subunit OspA vaccine markedly impacts the rate of newly acquired Borrelia burgdorferi infections in client-owned dogs living in a coastal community in Maine, USA.

    Science.gov (United States)

    Eschner, Andrew K; Mugnai, Kristen

    2015-02-10

    In North America, Borrelia burgdorferi is the causative bacterial agent of canine Lyme borreliosis and is transmitted following prolonged attachment and feeding of vector ticks, Ixodes scapularis or Ixodes pacificus. Its prevention is predicated upon tick-avoidance, effective on-animal tick control and effective immunization strategies. The purpose of this study is to characterize dogs that are newly seropositive for Borrelia burgdorferi infection in relation to compliant use of a recombinant OspA canine Lyme borreliosis vaccine. Specifically, Preventive Fractions (PF) and Risk Ratios (RR) associated with the degree of vaccine compliancy (complete versus incomplete) are determined. 6,202 dogs were tested over a five year period in a single veterinary hospital utilizing a non-adjuvanted, recombinant OspA vaccine according to a 0, 1, 6 month (then yearly) protocol. Rates of newly acquired "Lyme-positive" antibody test results were compared between protocol compliant and poorly compliant (incompletely and/or non-vaccinated) dogs. Over the five-year span, one percent (range 0.39 - 1.3) of protocol compliant vaccinated, previously antibody negative dogs became seropositive for infection. Approximately twenty-one percent (range 16.8 - 33.3) of incompletely vaccinated dogs became positive for infection-specific antibodies. The Preventative Fraction for testing positive for antibodies specific for infection with Borrelia burgdorferi in any given year based on optimal vaccine compliance was, on average, 95.3% (range 93.29 - 98.08). The Risk Ratio for becoming infected with Borrelia burgdorferi antibodies in any given year if vaccine non-compliant was 21.41 (range 14.9 - 52.1). There was a high statistically significant relationship (p = <0.0001) in the observed data in terms of vaccination protocol compliance and the probability of Borrelia burgdorferi infection in each of the five years under study. The recombinant outer surface protein A (rOspA) vaccine for dogs is highly

  3. Comparison of the live attenuated yellow fever vaccine 17D-204 strain to its virulent parental strain Asibi by deep sequencing.

    Science.gov (United States)

    Beck, Andrew; Tesh, Robert B; Wood, Thomas G; Widen, Steven G; Ryman, Kate D; Barrett, Alan D T

    2014-02-01

    The first comparison of a live RNA viral vaccine strain to its wild-type parental strain by deep sequencing is presented using as a model the yellow fever virus (YFV) live vaccine strain 17D-204 and its wild-type parental strain, Asibi. The YFV 17D-204 vaccine genome was compared to that of the parental strain Asibi by massively parallel methods. Variability was compared on multiple scales of the viral genomes. A modeled exploration of small-frequency variants was performed to reconstruct plausible regions of mutational plasticity. Overt quasispecies diversity is a feature of the parental strain, whereas the live vaccine strain lacks diversity according to multiple independent measurements. A lack of attenuating mutations in the Asibi population relative to that of 17D-204 was observed, demonstrating that the vaccine strain was derived by discrete mutation of Asibi and not by selection of genomes in the wild-type population. Relative quasispecies structure is a plausible correlate of attenuation for live viral vaccines. Analyses such as these of attenuated viruses improve our understanding of the molecular basis of vaccine attenuation and provide critical information on the stability of live vaccines and the risk of reversion to virulence.

  4. 75 FR 54589 - Availability of an Environmental Assessment for Field Testing Foot-and-Mouth Disease Vaccine...

    Science.gov (United States)

    2010-09-08

    ...] Availability of an Environmental Assessment for Field Testing Foot-and-Mouth Disease Vaccine, Live Adenovirus... unlicensed foot-and-mouth disease vaccine, live adenovirus vector. The EA, which is based on a risk analysis... testing following the close of the comment period for this notice unless new substantial issues bearing on...

  5. Protection of macaques with diverse MHC genotypes against a heterologous SIV by vaccination with a deglycosylated live-attenuated SIV.

    Directory of Open Access Journals (Sweden)

    Chie Sugimoto

    Full Text Available HIV vaccine development has been hampered by issues such as undefined correlates of protection and extensive diversity of HIV. We addressed these issues using a previously established SIV-macaque model in which SIV mutants with deletions of multiple gp120 N-glycans function as potent live attenuated vaccines to induce near-sterile immunity against the parental pathogenic SIVmac239. In this study, we investigated the protective efficacy of these mutants against a highly pathogenic heterologous SIVsmE543-3 delivered intravenously to rhesus macaques with diverse MHC genotypes. All 11 vaccinated macaques contained the acute-phase infection with blood viral loads below the level of detection between 4 and 10 weeks postchallenge (pc, following a transient but marginal peak of viral replication at 2 weeks in only half of the challenged animals. In the chronic phase, seven vaccinees contained viral replication for over 80 weeks pc, while four did not. Neutralizing antibodies against challenge virus were not detected. Although overall levels of SIV specific T cell responses did not correlate with containment of acute and chronic viral replication, a critical role of cellular responses in the containment of viral replication was suggested. Emergence of viruses with altered fitness due to recombination between the vaccine and challenge viruses and increased gp120 glycosylation was linked to the failure to control SIV. These results demonstrate the induction of effective protective immune responses in a significant number of animals against heterologous virus by infection with deglycosylated attenuated SIV mutants in macaques with highly diverse MHC background. These findings suggest that broad HIV cross clade protection is possible, even in hosts with diverse genetic backgrounds. In summary, results of this study indicate that deglycosylated live-attenuated vaccines may provide a platform for the elucidation of correlates of protection needed for a

  6. Identification of sequence changes in live attenuated goose parvovirus vaccine strains developed in Asia and Europe.

    Science.gov (United States)

    Shien, J-H; Wang, Y-S; Chen, C-H; Shieh, H K; Hu, C-C; Chang, P-C

    2008-10-01

    Live attenuated vaccines have been used for control of the disease caused by goose parvovirus (GPV), but the mechanism involved in attenuation of GPV remains elusive. This report presents the complete nucleotide sequences of two live attenuated strains of GPV (82-0321V and VG32/1) that were independently developed in Taiwan and Europe, together with the parental strain of 82-0321V and a field strain isolated in Taiwan in 2006. Sequence comparisons showed that 82-0321V and VG32/1 had multiple deletions and substitutions in the inverted terminal repeats region when compared with their parental strain or the field virus, but these changes did not affect the formation of the hairpin structure essential for viral replication. Moreover, 82-0321V and VG32/1 had five amino acid changes in the non-structural protein, but these changes were located at positions distant from known functional motifs in the non-structural protein. In contrast, 82-0321V had nine changes and VG32/1 had 11 changes in their capsid proteins (VP1), and the majority of these changes occurred at positions close to the putative receptor binding sites of VP1, as predicted using the structure of adeno-associated virus 2 as the model system. Taken together, the results suggest that changes in sequence near the receptor binding sites of VP1 might be responsible for attenuation of GPV. This is the first report of complete nucleotide sequences of GPV other than the virulent B strain, and suggests a possible mechanism for attenuation of GPV.

  7. Public health impact and cost-effectiveness of intranasal live attenuated influenza vaccination of children in Germany.

    Science.gov (United States)

    Damm, Oliver; Eichner, Martin; Rose, Markus Andreas; Knuf, Markus; Wutzler, Peter; Liese, Johannes Günter; Krüger, Hagen; Greiner, Wolfgang

    2015-06-01

    In 2011, intranasally administered live attenuated influenza vaccine (LAIV) was approved in the EU for prophylaxis of seasonal influenza in 2-17-year-old children. Our objective was to estimate the potential epidemiological impact and cost-effectiveness of an LAIV-based extension of the influenza vaccination programme to healthy children in Germany. An age-structured dynamic model of influenza transmission was developed and combined with a decision-tree to evaluate different vaccination strategies in the German health care system. Model inputs were based on published literature or were derived by expert consulting using the Delphi technique. Unit costs were drawn from German sources. Under base-case assumptions, annual routine vaccination of children aged 2-17 years with LAIV assuming an uptake of 50% would prevent, across all ages, 16 million cases of symptomatic influenza, over 600,000 cases of acute otitis media, nearly 130,000 cases of community-acquired pneumonia, nearly 1.7 million prescriptions of antibiotics and over 165,000 hospitalisations over 10 years. The discounted incremental cost-effectiveness ratio was 1,228 per quality-adjusted life year gained from a broad third-party payer perspective (including reimbursed direct costs and specific transfer payments), when compared with the current strategy of vaccinating primarily risk groups with the conventional trivalent inactivated vaccine. Inclusion of patient co-payments and indirect costs in terms of productivity losses resulted in discounted 10-year cost savings of 3.4 billion. In conclusion, adopting universal influenza immunisation of healthy children and adolescents would lead to a substantial reduction in influenza-associated disease at a reasonable cost to the German statutory health insurance system. On the basis of the epidemiological and health economic simulation results, a recommendation of introducing annual routine influenza vaccination of children 2-17 years of age might be taken into

  8. Dengue vaccines: Challenges, development, current status and prospects

    Directory of Open Access Journals (Sweden)

    A Ghosh

    2015-01-01

    Full Text Available Infection with dengue virus (DENV is the most rapidly spreading mosquito-borne viral disease in the world. The clinical spectrum of dengue, caused by any of the four serotypes of DENV, ranges from mild self-limiting dengue fever to severe dengue, in the form dengue hemorrhagic fever (DHF and dengue shock syndrome (DSS. Increased rates of hospitalization due to severe dengue, during outbreaks, result in massive economic losses and strained health services. In the absence of specific antiviral therapy, control of transmission of DENV by vector management is the sole method available for decreasing dengue-associated morbidity. Since vector control strategies alone have not been able to satisfactorily achieve reduction in viral transmission, the implementation of a safe, efficacious and cost-effective dengue vaccine as a supplementary measure is a high public health priority. However, the unique and complex immunopathology of dengue has complicated vaccine development. Dengue vaccines have also been challenged by critical issues like lack of animal models for the disease and absence of suitable markers of protective immunity. Although no licensed dengue vaccine is yet available, several vaccine candidates are under phases of development, including live attenuated virus vaccines, live chimeric virus vaccines, inactivated virus vaccines, subunit vaccines, DNA vaccines and viral-vectored vaccines. Although some vaccine candidates have progressed from animal trials to phase II and III in humans, a number of issues regarding implementation of dengue vaccine in countries like India still need to be addressed. Despite the current limitations, collaborative effects of regulatory bodies like World Health Organization with vaccine manufacturers and policy makers, to facilitate vaccine development and standardize field trials can make a safe and efficacious dengue vaccine a reality in near future.

  9. A novel multiplex poliovirus binding inhibition assay applicable for large serosurveillance and vaccine studies, without the use of live poliovirus.

    Science.gov (United States)

    Schepp, Rutger M; Berbers, Guy A M; Ferreira, José A; Reimerink, Johan H; van der Klis, Fiona R

    2017-03-01

    Large-scale serosurveillance or vaccine studies for poliovirus using the "gold standard" WHO neutralisation test (NT) are very laborious and time consuming. With the polio eradication at hand and with the removal of live attenuated Sabin strains from the oral poliovirus vaccine (OPV), starting with type 2 (as of April 2016), laboratories will need to conform to much more stringent laboratory biosafety regulations when handling live poliovirus strains. In this study, a poliovirus binding inhibition multiplex immunoassay (polio MIA) using inactivated poliovirus vaccine (IPV-Salk) was developed for simultaneous quantification of serum antibodies directed to all three poliovirus types. Our assay shows a good correlation with the NT and an excellent correlation with the ELISA-based binding inhibition assay (POBI). The assay is highly type-specific and reproducible. Additionally, serum sample throughput increases about fivefold relative to NT and POBI and the amount of serum needed is reduced by more than 90%. In conclusion, the polio MIA can be used as a safe and high throughput application, especially for large-scale surveillance and vaccine studies, reducing laboratory time and serum amounts needed. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  10. Temperature-sensitive mutations for live-attenuated Rift Valley fever vaccines: Implications from other RNA viruses

    Directory of Open Access Journals (Sweden)

    Shoko eNishiyama

    2015-08-01

    Full Text Available Rift Valley fever (RVF is a mosquito-borne zoonotic disease endemic to the African continent. RVF is characterized by high rate of abortions in ruminants and hemorrhagic fever, encephalitis or blindness in humans. RVF is caused by the Rift Valley fever virus (RVFV: genus Phlebovirus, family Bunyaviridae. Vaccination is the only known effective strategy to prevent the disease, but there are no licensed RVF vaccines available for humans. A live-attenuated vaccine candidate derived from the wild-type pathogenic Egyptian ZH548 strain, MP-12, has been conditionally licensed for veterinary use in the United States. MP-12 displays a temperature-sensitive (ts phenotype and does not replicate at 41oC. The ts mutation limits viral replication at a specific body temperature and may lead to an attenuation of the virus. Here we will review well-characterized ts mutations for RNA viruses, and further discuss the potential in designing novel live-attenuated vaccines for RVF.

  11. Avian metapneumovirus M2:2 protein inhibits replication in Vero cells: modification facilitates live vaccine development.

    Science.gov (United States)

    Clubbe, Jayne; Naylor, Clive J

    2011-11-28

    Throughout the world, avian metapneumovirus (AMPV) infection of subtype A is principally controlled by two live vaccines both derived from UK field strain #8544. Improvements of those vaccines by use of reverse genetics technology was found to be hampered by the inability of #8544 to replicate in the commonly exploited Vero cell based reverse genetics system. A systematic reverse genetics based genome modification of a DNA copy of #8544, employing sequence data from a Vero grown, #8544 derived, live vaccine; was used to determine mutations required to facilitate virus recovery and replication in Vero cells. This identified a single coding substitution in the M2:2 reading frame as responsible. Furthermore, ablation of M2:2 was found to elicit the same outcome. M2:2 sequence analysis of seven AMPVs found Vero cell adaption to be associated with non similar amino acid changes in M2:2. The study shows that M2:2 modification of field virus #8544 will enable research leading to improved vaccines. This may have more general application to other AMPV field strains. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Humoral and cellular immune responses to Yersinia pestis Pla antigen in humans immunized with live plague vaccine.

    Science.gov (United States)

    Feodorova, Valentina A; Lyapina, Anna M; Khizhnyakova, Maria A; Zaitsev, Sergey S; Sayapina, Lidiya V; Arseneva, Tatiana E; Trukhachev, Alexey L; Lebedeva, Svetlana A; Telepnev, Maxim V; Ulianova, Onega V; Lyapina, Elena P; Ulyanov, Sergey S; Motin, Vladimir L

    2018-06-01

    To establish correlates of human immunity to the live plague vaccine (LPV), we analyzed parameters of cellular and antibody response to the plasminogen activator Pla of Y. pestis. This outer membrane protease is an essential virulence factor that is steadily expressed by Y. pestis. PBMCs and sera were obtained from a cohort of naïve (n = 17) and LPV-vaccinated (n = 34) donors. Anti-Pla antibodies of different classes and IgG subclasses were determined by ELISA and immunoblotting. The analysis of antibody response was complicated with a strong reactivity of Pla with normal human sera. The linear Pla B-cell epitopes were mapped using a library of 15-mer overlapping peptides. Twelve peptides that reacted specifically with sera of vaccinated donors were found together with a major cross-reacting peptide IPNISPDSFTVAAST located at the N-terminus. PBMCs were stimulated with recombinant Pla followed by proliferative analysis and cytokine profiling. The T-cell recall response was pronounced in vaccinees less than a year post-immunization, and became Th17-polarized over time after many rounds of vaccination. The Pla protein can serve as a biomarker of successful vaccination with LPV. The diagnostic use of Pla will require elimination of cross-reactive parts of the antigen.

  13. Vector independent transmission of the vector-borne bluetongue virus.

    Science.gov (United States)

    van der Sluijs, Mirjam Tineke Willemijn; de Smit, Abraham J; Moormann, Rob J M

    2016-01-01

    Bluetongue is an economically important disease of ruminants. The causative agent, Bluetongue virus (BTV), is mainly transmitted by insect vectors. This review focuses on vector-free BTV transmission, and its epizootic and economic consequences. Vector-free transmission can either be vertical, from dam to fetus, or horizontal via direct contract. For several BTV-serotypes, vertical (transplacental) transmission has been described, resulting in severe congenital malformations. Transplacental transmission had been mainly associated with live vaccine strains. Yet, the European BTV-8 strain demonstrated a high incidence of transplacental transmission in natural circumstances. The relevance of transplacental transmission for the epizootiology is considered limited, especially in enzootic areas. However, transplacental transmission can have a substantial economic impact due to the loss of progeny. Inactivated vaccines have demonstrated to prevent transplacental transmission. Vector-free horizontal transmission has also been demonstrated. Since direct horizontal transmission requires close contact of animals, it is considered only relevant for within-farm spreading of BTV. The genetic determinants which enable vector-free transmission are present in virus strains circulating in the field. More research into the genetic changes which enable vector-free transmission is essential to better evaluate the risks associated with outbreaks of new BTV serotypes and to design more appropriate control measures.

  14. Priming T-cell responses with recombinant measles vaccine vector in a heterologous prime-boost setting in non-human primates

    NARCIS (Netherlands)

    Bolton, Diane L.; Santra, Sampa; Swett-Tapia, Cindy; Custers, Jerome; Song, Kaimei; Balachandran, Harikrishnan; Mach, Linh; Naim, Hussein; Kozlowski, Pamela A.; Lifton, Michelle; Goudsmit, Jaap; Letvin, Norman; Roederer, Mario; Radošević, Katarina

    2012-01-01

    Licensed live attenuated virus vaccines capable of expressing transgenes from other pathogens have the potential to reduce the number of childhood immunizations by eliciting robust immunity to multiple pathogens simultaneously. Recombinant attenuated measles virus (rMV) derived from the Edmonston

  15. Simultaneous immunization of cattle with foot-and-mouth disease (FMD and live anthrax vaccines do not interfere with FMD booster responses

    Directory of Open Access Journals (Sweden)

    Myrian Trotta

    2015-01-01

    Full Text Available Foot-and-mouth disease (FMD vaccination in Argentina is compulsory for most of the cattle population and conducted by certified veterinarians. This organized campaign may facilitate the controlled application of other vaccines against endemic diseases, provided immune responses against FMD are not hindered. There is no published information on the interference of immunity against FMD vaccines when applied together with a live bacterial vaccine. In this study we evaluated if the simultaneous application of a Bacillus anthracis live vaccine with a commercial tetravalent oil-based FMD vaccine (FMD-vac used in Argentina, modifies the antibody booster responses against FMD virus (FMDV in cattle. Two groups of 16 heifers with comparable liquid phase blocking ELISA (LPBE titers were immunized with the FMD-vac alone or simultaneously with a commercial attenuated bovine anthrax Sterne strain vaccine (ABV. Serum samples were obtained at 0, 25, 60 and 90 days post vaccination (dpv and specific antibodies against two FMDV vaccine strains were assessed by LPBE, avidity and IgG-isotype ELISAs. Bovines immunized with FMD-vac or FMDV-V + ABV responded with a boost in the LPBE antibody titers and avidity at 25 dpv, and remained within similar levels up to the end of the study. Animals vaccinated with FMD-vac + ABV had significantly higher LPBE titers at 25 dpv, compared to those immunized with FMD-vac alone; which was due to an increase in IgG2 titers. Overall, antibody titers elicited in both groups were similar and followed comparable kinetics over time. We conclude that the simultaneous application of a live anthrax vaccine with the current FMD tetravalent vaccine used in Argentina in cattle previously immunized against FMD, did not counteract the serological response induced by FMD vaccination.

  16. Development of a gravid trap for collecting live malaria vectors Anopheles gambiae s.l.

    Directory of Open Access Journals (Sweden)

    Sisay Dugassa

    Full Text Available Effective malaria vector control targeting indoor host-seeking mosquitoes has resulted in fewer vectors entering houses in many areas of sub-Saharan Africa, with the proportion of vectors outdoors becoming more important in the transmission of this disease. This study aimed to develop a gravid trap for the outdoor collection of the malaria vector Anopheles gambiae s.l. based on evaluation and modification of commercially available gravid traps.Experiments were implemented in an 80 m(2 semi-field system where 200 gravid Anopheles gambiae s.s. were released nightly. The efficacy of the Box, CDC and Frommer updraft gravid traps was compared. The Box gravid trap was tested to determine if the presence of the trap over water and the trap's sound affected catch size. Mosquitoes approaching the treatment were evaluated using electrocuting nets or detergents added to the water in the trap. Based on the results, a new gravid trap (OviART trap that provided an open, unobstructed oviposition site was developed and evaluated.Box and CDC gravid traps collected similar numbers (relative rate (RR 0.8, 95% confidence interval (CI 0.6-1.2; p = 0.284, whereas the Frommer trap caught 70% fewer mosquitoes (RR 0.3, 95% CI 0.2-0.5; p < 0.001. The number of mosquitoes approaching the Box trap was significantly reduced when the trap was positioned over a water-filled basin compared to an open pond (RR 0.7 95% CI 0.6-0.7; p < 0.001. This effect was not due to the sound of the trap. Catch size increased by 60% (RR 1.6, 1.2-2.2; p = 0.001 with the new OviART trap.Gravid An. Gambiae s.s. females were visually deterred by the presence of the trapping device directly over the oviposition medium. Based on these investigations, an effective gravid trap was developed that provides open landing space for egg-laying Anopheles.

  17. Studies on comparative immune response of broiler chicken to different imported live infectious bursal disease vaccines

    International Nuclear Information System (INIS)

    Shoukat, T.M.; Sheikh, M.A.; Akhtar, S.S.; Hassan, S.S.

    2007-01-01

    In the present study the comparative efficacy of different vaccines was carried out. These include Gumbokal. Vaccine, IBA-Vac and IBD, Vac. The vaccines were evaluated on the basis of immure response developed by using indirect haemaggtutination (IHA) test in all the birds the presence of material antibodies on day first of their age by IHA. The titre varied from 1:4 to 1:6. All the vaccinated group and control group was examined for their immune response on the 7th and then gradual increase in titre occurred on day 15th and highest values were observed on 30th day post vaccination. All the three vaccines gave identical results as far as their efficacy against IBDV infection was concerned. (author)

  18. Highly-Immunogenic Virally-Vectored T-cell Vaccines Cannot Overcome Subversion of the T-cell Response by HCV during Chronic Infection

    Directory of Open Access Journals (Sweden)

    Leo Swadling

    2016-08-01

    Full Text Available An effective therapeutic vaccine for the treatment of chronic hepatitis C virus (HCV infection, as an adjunct to newly developed directly-acting antivirals (DAA, or for the prevention of reinfection, would significantly reduce the global burden of disease associated with chronic HCV infection. A recombinant chimpanzee adenoviral (ChAd3 vector and a modified vaccinia Ankara (MVA, encoding the non-structural proteins of HCV (NSmut, used in a heterologous prime/boost regimen induced multi-specific, high-magnitude, durable HCV-specific CD4+ and CD8+ T-cell responses in healthy volunteers, and was more immunogenic than a heterologous Ad regimen. We now assess the immunogenicity of this vaccine regimen in HCV infected patients (including patients with a low viral load suppressed with interferon/ribavirin therapy, determine T-cell cross-reactivity to endogenous virus, and compare immunogenicity with that observed previously in both healthy volunteers and in HCV infected patients vaccinated with the heterologous Ad regimen. Vaccination of HCV infected patients with ChAd3-NSmut/MVA-NSmut was well tolerated. Vaccine-induced HCV-specific T-cell responses were detected in 8/12 patients; however, CD4+ T-cell responses were rarely detected, and the overall magnitude of HCV-specific T-cell responses was markedly reduced when compared to vaccinated healthy volunteers. Furthermore, HCV-specific cells had a distinct partially-functional phenotype (lower expression of activation markers, granzyme B, and TNFα production, weaker in vitro proliferation, and higher Tim3 expression, with comparable Tbet and Eomes expression compared to healthy volunteers. Robust anti-vector T-cells and antibodies were induced, showing that there is no global defect in immunity. The level of viremia at the time of vaccination did not correlate with the magnitude of the vaccine-induced T-cell response. Full-length, next-generation sequencing of the circulating virus demonstrated that T

  19. [Immunization with Bifidobacterium bifidum-vectored OprI vaccine of Pseudomonas aeruginosa enhances inhibitory effect on P. aeruginosa in mice].

    Science.gov (United States)

    Liu, Xiao; Li, Wengui

    2017-08-01

    Objective To study the pulmonary bacterial loads, splenocyte proliferation, distributions of T cell subsets and cell apoptosis in mice immunized with Bifidobacterium bifidum-vectored OprI (Bb-OprI) vaccine of Pseudomonas aeruginosa and challenged with P. aeruginosa PA01 strain. Methods BALB/c mice were immunized with 5×10 9 CFUs of vaccine by intragastric administration, 3 times a week for 3 weeks, and challenged intranasally with 5×10 6 CFUs of PA01 strain at the fourth week after the first immunization. At the second week after the challenge, all mice were sacrificed to separate their lungs and spleens, and the pulmonary bacterial loads were counted. The proliferation of the splenocytes was determined by MTT assay. The splenic CD4 + , CD8 + T cell subsets and the apoptotic rate of splenocytes were detected by flow cytometry. Results The number of pulmonary bacterial colonies in the mice immunized with the vaccine and challenged with PA01 strain decreased, while the proliferation of splenocytes and the proportion of CD4 + T cells markedly increased, and the apoptosis of splenocytes was notably reduced. Conclusion The intragastric vaccination of recombinant Bb-OprI vaccine can increase the proportion of CD4 + T cells and enhance the inhibitory effect on P. aeruginosa.

  20. Multiagent vaccines vectored by Venezuelan equine encephalitis virus replicon elicits immune responses to Marburg virus and protection against anthrax and botulinum neurotoxin in mice.

    Science.gov (United States)

    Lee, John S; Groebner, Jennifer L; Hadjipanayis, Angela G; Negley, Diane L; Schmaljohn, Alan L; Welkos, Susan L; Smith, Leonard A; Smith, Jonathan F

    2006-11-17

    The development of multiagent vaccines offers the advantage of eliciting protection against multiple diseases with minimal inoculations over a shorter time span. We report here the results of using formulations of individual Venezuelan equine encephalitis (VEE) virus replicon-vectored vaccines against a bacterial disease, anthrax; a viral disease, Marburg fever; and against a toxin-mediated disease, botulism. The individual VEE replicon particles (VRP) expressed mature 83-kDa protective antigen (MAT-PA) from Bacillus anthracis, the glycoprotein (GP) from Marburg virus (MBGV), or the H(C) fragment from botulinum neurotoxin (BoNT H(C)). CBA/J mice inoculated with a mixture of VRP expressing BoNT H(C) serotype C (BoNT/C H(C)) and MAT-PA were 80% protected from a B. anthracis (Sterne strain) challenge and then 100% protected from a sequential BoNT/C challenge. Swiss mice inoculated with individual VRP or with mixtures of VRP vaccines expressing BoNT H(C) serotype A (BoNT/A H(C)), MAT-PA, and MBGV-GP produced antibody responses specific to the corresponding replicon-expressed protein. Combination of the different VRP vaccines did not diminish the antibody responses measured for Swiss mice inoculated with formulations of two or three VRP vaccines as compared to mice that received only one VRP vaccine. Swiss mice inoculated with VRP expressing BoNT/A H(C) alone or in combination with VRP expressing MAT-PA and MBGV GP, were completely protected from a BoNT/A challenge. These studies demonstrate the utility of combining individual VRP vaccines into multiagent formulations for eliciting protective immune responses to various types of diseases.

  1. Vaccine process technology.

    Science.gov (United States)

    Josefsberg, Jessica O; Buckland, Barry

    2012-06-01

    The evolution of vaccines (e.g., live attenuated, recombinant) and vaccine production methods (e.g., in ovo, cell culture) are intimately tied to each other. As vaccine technology has advanced, the methods to produce the vaccine have advanced and new vaccine opportunities have been created. These technologies will continue to evolve as we strive for safer and more immunogenic vaccines and as our understanding of biology improves. The evolution of vaccine process technology has occurred in parallel to the remarkable growth in the development of therapeutic proteins as products; therefore, recent vaccine innovations can leverage the progress made in the broader biotechnology industry. Numerous important legacy vaccines are still in use today despite their traditional manufacturing processes, with further development focusing on improving stability (e.g., novel excipients) and updating formulation (e.g., combination vaccines) and delivery methods (e.g., skin patches). Modern vaccine development is currently exploiting a wide array of novel technologies to create safer and more efficacious vaccines including: viral vectors produced in animal cells, virus-like particles produced in yeast or insect cells, polysaccharide conjugation to carrier proteins, DNA plasmids produced in E. coli, and therapeutic cancer vaccines created by in vitro activation of patient leukocytes. Purification advances (e.g., membrane adsorption, precipitation) are increasing efficiency, while innovative analytical methods (e.g., microsphere-based multiplex assays, RNA microarrays) are improving process understanding. Novel adjuvants such as monophosphoryl lipid A, which acts on antigen presenting cell toll-like receptors, are expanding the previously conservative list of widely accepted vaccine adjuvants. As in other areas of biotechnology, process characterization by sophisticated analysis is critical not only to improve yields, but also to determine the final product quality. From a regulatory

  2. Improving Mycobacterium bovis bacillus Calmette-Guèrin as a vaccine delivery vector for viral antigens by incorporation of glycolipid activators of NKT cells.

    Science.gov (United States)

    Venkataswamy, Manjunatha M; Ng, Tony W; Kharkwal, Shalu S; Carreño, Leandro J; Johnson, Alison J; Kunnath-Velayudhan, Shajo; Liu, Zheng; Bittman, Robert; Jervis, Peter J; Cox, Liam R; Besra, Gurdyal S; Wen, Xiangshu; Yuan, Weiming; Tsuji, Moriya; Li, Xiangming; Ho, David D; Chan, John; Lee, Sunhee; Frothingham, Richard; Haynes, Barton F; Panas, Michael W; Gillard, Geoffrey O; Sixsmith, Jaimie D; Korioth-Schmitz, Birgit; Schmitz, Joern E; Larsen, Michelle H; Jacobs, William R; Porcelli, Steven A

    2014-01-01

    Recombinant Mycobacterium bovis bacillus Calmette-Guèrin (rBCG) has been explored as a vector for vaccines against HIV because of its ability to induce long lasting humoral and cell mediated immune responses. To maximize the potential for rBCG vaccines to induce effective immunity against HIV, various strategies are being employed to improve its ability to prime CD8+ T cells, which play an important role in the control of HIV infections. In this study we adopted a previously described approach of incorporating glycolipids that activate CD1d-restricted natural killer T (NKT) cells to enhance priming of CD8+ T cells by rBCG strains expressing an SIV Gag antigen (rBCG-SIV gag). We found that the incorporation of the synthetic NKT activating glycolipid α-galactosylceramide (α-GC) into rBCG-SIV gag significantly enhanced CD8+ T cell responses against an immunodominant Gag epitope, compared to responses primed by unmodified rBCG-SIV gag. The abilities of structural analogues of α-GC to enhance CD8+ T cell responses to rBCG were compared in both wild type and partially humanized mice that express human CD1d molecules in place of mouse CD1d. These studies identified an α-GC analogue known as 7DW8-5, which has previously been used successfully as an adjuvant in non-human primates, as a promising compound for enhancing immunogenicity of antigens delivered by rBCG.vectors. Our findings support the incorporation of synthetic glycolipid activators of NKT cells as a novel approach to enhance the immunogenicity of rBCG-vectored antigens for induction of CD8+ T cell responses. The glycolipid adjuvant 7DW8-5 may be a promising candidate for advancing to non-human primate and human clinical studies for the development of HIV vaccines based on rBCG vectors.

  3. Improving Mycobacterium bovis bacillus Calmette-Guèrin as a vaccine delivery vector for viral antigens by incorporation of glycolipid activators of NKT cells.

    Directory of Open Access Journals (Sweden)

    Manjunatha M Venkataswamy

    Full Text Available Recombinant Mycobacterium bovis bacillus Calmette-Guèrin (rBCG has been explored as a vector for vaccines against HIV because of its ability to induce long lasting humoral and cell mediated immune responses. To maximize the potential for rBCG vaccines to induce effective immunity against HIV, various strategies are being employed to improve its ability to prime CD8+ T cells, which play an important role in the control of HIV infections. In this study we adopted a previously described approach of incorporating glycolipids that activate CD1d-restricted natural killer T (NKT cells to enhance priming of CD8+ T cells by rBCG strains expressing an SIV Gag antigen (rBCG-SIV gag. We found that the incorporation of the synthetic NKT activating glycolipid α-galactosylceramide (α-GC into rBCG-SIV gag significantly enhanced CD8+ T cell responses against an immunodominant Gag epitope, compared to responses primed by unmodified rBCG-SIV gag. The abilities of structural analogues of α-GC to enhance CD8+ T cell responses to rBCG were compared in both wild type and partially humanized mice that express human CD1d molecules in place of mouse CD1d. These studies identified an α-GC analogue known as 7DW8-5, which has previously been used successfully as an adjuvant in non-human primates, as a promising compound for enhancing immunogenicity of antigens delivered by rBCG.vectors. Our findings support the incorporation of synthetic glycolipid activators of NKT cells as a novel approach to enhance the immunogenicity of rBCG-vectored antigens for induction of CD8+ T cell responses. The glycolipid adjuvant 7DW8-5 may be a promising candidate for advancing to non-human primate and human clinical studies for the development of HIV vaccines based on rBCG vectors.

  4. Use of the live attenuated Japanese Encephalitis vaccine SA 14-14-2 in children: A review of safety and tolerability studies.

    Science.gov (United States)

    Ginsburg, Amy Sarah; Meghani, Ankita; Halstead, Scott B; Yaich, Mansour

    2017-10-03

    Japanese encephalitis (JE) is the leading cause of viral neurological disease and disability in Asia. Some 50-80% of children with clinical JE die or have long-term neurologic sequelae. Since there is no cure, human vaccination is the only effective long-term control measure, and the World Health Organization recommends that at-risk populations receive a safe and effective vaccine. Four different types of JE vaccines are currently available: inactivated mouse brain-derived vaccines, inactivated Vero cell vaccines, live attenuated SA 14-14-2 vaccines and a live recombinant (chimeric) vaccine. With the rapidly increasing demand for and availability and use of JE vaccines, countries face an important decision in the selection of a JE vaccine. This article provides a comprehensive review of the available safety literature for the live attenuated SA 14-14-2 JE vaccine (LAJEV), the most widely used new generation JE vaccine. With well-established effectiveness data, a single dose of LAJEV protects against clinical JE disease for at least 5 years, providing a long duration of protection compared with inactivated mouse brain-derived vaccines. Since 1988, about 700 million doses of the LAJEV have been distributed globally. Our review found that LAJEV is well tolerated across a wide age range and can safely be given to children as young as 8 months of age. While serious adverse events attributable to LAJEV have been reported, independent experts have not found sufficient evidence for causality based on the available data.

  5. Adenovirus type 35-vectored tuberculosis vaccine has an acceptable safety and tolerability profile in healthy, BCG-vaccinated, QuantiFERON(®)-TB Gold (+) Kenyan adults without evidence of tuberculosis.

    Science.gov (United States)

    Walsh, Douglas S; Owira, Victorine; Polhemus, Mark; Otieno, Lucas; Andagalu, Ben; Ogutu, Bernhards; Waitumbi, John; Hawkridge, Anthony; Shepherd, Barbara; Pau, Maria Grazia; Sadoff, Jerald; Douoguih, Macaya; McClain, J Bruce

    2016-05-05

    In a Phase 1 trial, we evaluated the safety of AERAS-402, an adenovirus 35-vectored TB vaccine candidate expressing 3 Mycobacterium tuberculosis (Mtb) immunodominant antigens, in subjects with and without latent Mtb infection. HIV-negative, BCG-vaccinated Kenyan adults without evidence of tuberculosis, 10 QuantiFERON(®)-TB Gold In-Tube test (QFT-G)(-) and 10 QFT-G(+), were randomized 4:1 to receive AERAS-402 or placebo as two doses, on Days 0 and 56, with follow up to Day 182. There were no deaths, serious adverse events or withdrawals. For 1 AERAS-402 QFT-G(-) and 1 AERAS-402 QFT-G(+) subject, there were 3 self-limiting severe AEs of injection site pain: 1 after the first vaccination and 1 after each vaccination, respectively. Two additional severe AEs considered vaccine-related were reported after the first vaccination in AERAS-402 QFT-G(+) subjects: elevated blood creatine phosphokinase and neutropenia, the latter slowly improving but remaining abnormal until study end. AERAS-402 was not detected in urine or throat cultures for any subject. In intracellular cytokine staining studies, curtailed by technical issues, we saw modest CD4+ and CD8+ T cell responses to Mtb Ag85A/b peptide pools among both QFT-G(-) and (+) subjects, with trends in the CD4+ T cells suggestive of boosting after the second vaccine dose, slightly more so in QFT-G(+) subjects. CD4+ and CD8+ responses to Mtb antigen TB10.4 were minimal. Increases in Adenovirus 35 neutralizing antibodies from screening to end of study, seen in 50% of AERAS-402 recipients, were mostly minimal. This small study confirms acceptable safety and tolerability profiles for AERAS-402, in line with other Phase 1 studies of AERAS-402, now to include QFT-G(+) subjects. Published by Elsevier Ltd.

  6. Zika virus: Vaccine initiatives and obstacles

    Directory of Open Access Journals (Sweden)

    Reema Mukherjee

    2017-01-01

    Full Text Available Over 130,000 humans in Brazil are infected with Zika virus (ZIKV since March 2015, and presently 29 countries in Americas have reported local autochthonous ZIKV transmission. Besides the associated clinical features, Brazil has also reported a temporal and spatial association of ZIKV with Guillain-Barre syndrome (GBS and Zika fetal syndrome. ZIKV vaccine approaches include purified inactivated virus, nucleic acid-based vaccines (DNA, RNA, live vector vaccines, subunit vaccines, virus-like particle technologies, and live recombinant vaccines similar to the technologies used against other human flaviviruses. At present, 15 commercial entities are involved in the development of ZIKV vaccine. Vaccines developed through different approaches would have their own inherent advantages and disadvantages. The presentation of disease in different populations and lack of clarity on the pathogenesis and complications is the most important obstacle. Second, Zika belongs to a genus that is notorious for the antibody-mediated enhancement of infection, which proved to be a stumbling block during the development of the dengue vaccine. Identifying large naive and yet uninfected at-risk populations may be an obstacle to demonstrating efficacy. Next, the association of Zika with GBS is being researched since the vaccine may have the potential to provoke similar neuropathophysiologic mechanisms. Zika's association with adverse fetal outcomes necessitates that pregnant women and women of childbearing age are considered for evaluating vaccines, which form a vulnerable group for vaccine trials.

  7. Enrollment in YFV Vaccine Trial: An Evaluation of Recruitment Outcomes Associated with a Randomized Controlled Double-Blind Trial of a Live Attenuated Yellow Fever Vaccine.

    Science.gov (United States)

    Frew, Paula M; Shapiro, Eve T; Lu, Lu; Edupuganti, Srilatha; Keyserling, Harry L; Mulligan, Mark J

    2013-04-15

    This investigation evaluated several factors associated with diverse participant enrollment of a clinical trial assessing safety, immunogenicity, and comparative viremia associated with administration of 17-D live, attenuated yellow fever vaccine given alone or in combination with human immune globulin. We obtained baseline participant information (e.g., sociodemographic, medical) and followed recruitment outcomes from 2005 to 2007. Of 355 potential Yellow Fever vaccine study participants, 231 cases were analyzed. Strong interest in study participation was observed among racial and ethnically diverse persons with 36.34% eligible following initial study screening, resulting in 18.75% enrollment. The percentage of white participants increased from 63.66% (prescreened sample) to 81.25% (enrollment group). The regression model was significant with white race as a predictor of enrollment (OR=2.744, 95% CI=1.415-5.320, p=0.003).In addition, persons were more likely to enroll via direct outreach and referral mechanisms compared to mass advertising (OR=2.433, 95% CI=1.102-5.369). The findings indicate that racially diverse populations can be recruited to vaccine clinical trials, yet actual enrollment may not reflect that diversity.

  8. Production of cell culture (MDCK) derived live attenuated influenza vaccine (LAIV) in a fully disposable platform process.

    Science.gov (United States)

    George, Meena; Farooq, Masiha; Dang, Thi; Cortes, Bernadette; Liu, Jonathan; Maranga, Luis

    2010-08-15

    The majority of influenza vaccines are manufactured using embryonated hens' eggs. The potential occurrence of a pandemic outbreak of avian influenza might reduce or even eliminate the supply of eggs, leaving the human population at risk. Also, the egg-based production technology is intrinsically cumbersome and not easily scalable to provide a rapid worldwide supply of vaccine. In this communication, the production of a cell culture (Madin-Darby canine kidney (MDCK)) derived live attenuated influenza vaccine (LAIV) in a fully disposable platform process using a novel Single Use Bioreactor (SUB) is presented. The cell culture and virus infection was maintained in a disposable stirred tank reactor with PID control of pH, DO, agitation, and temperature, similar to traditional glass or stainless steel bioreactors. The application of this technology was tested using MDCK cells grown on microcarriers in proprietary serum free medium and infection with 2006/2007 seasonal LAIV strains at 25-30 L scale. The MDCK cell growth was optimal at the agitation rate of 100 rpm. Optimization of this parameter allowed the cells to grow at a rate similar to that achieved in the conventional 3 L glass stirred tank bioreactors. Influenza vaccine virus strains, A/New Caledonia/20/99 (H1N1 strain), A/Wisconsin/67/05 (H3N2 strain), and B/Malaysia/2506/04 (B strain) were all successfully produced in SUB with peak virus titers > or =8.6 log(10) FFU/mL. This result demonstrated that more than 1 million doses of vaccine can be produced through one single run of a small bioreactor at the scale of 30 L and thus provided an alternative to the current vaccine production platform with fast turn-around and low upfront facility investment, features that are particularly useful for emerging and developing countries and clinical trial material production.

  9. Distinction between infections with European and American/vaccine type PRRS virus after vaccination with a modified-live PRRS virus vaccine

    DEFF Research Database (Denmark)

    Bøtner, Anette; Strandbygaard, Bertel; Sørensen, K. J.

    2000-01-01

    types of PRRSV was made on a serological basis. The immunoperoxidase monolayer assay (IPMA), carried out using a Danish strain (IPMA/DK) and the vaccine strain (IPMA/vac) in parallel, allows the distinction of infections with EU and US strains of PRRSV. In herds infected with the EU type, the titer...... in individual samples is higher in the IPMA/DK compared to the titer in the IPMA/vac, while in herds infected with the vaccine/US type, the titers are highest in the IPMA/vac. Furthermore, a double blocking ELISA has been developed, which enables large scale screening for and simultaneous distinction between...... ELISA-Vac), which enables us to serologically distinguish between EU and US strains of PRRSV infections. In herds infected with the Danish strain of PRRSV, most animals have a ratio below 1, while in herds infected with the vaccine/US strain most animals have a ratio above 2. The distinction between...

  10. "Saving lives": Adapting and adopting Human Papilloma Virus (HPV) vaccination in Austria.

    Science.gov (United States)

    Paul, Katharina T

    2016-03-01

    Vaccination against the sexually transmitted Human Papilloma Virus (HPV), a necessary agent for the development of cervical cancer, has triggered much debate. In Austria, HPV policy turned from "lagging behind" in 2008 into "Europe's frontrunner" by 2013. Drawing on qualitative research, the article shows how the vaccine was transformed and made "good enough" over the course of five years. By means of tinkering and shifting storylines, policy officials and experts disassociated the vaccine from gender, vaccine manufacturers, and youth sexuality. Ultimately, the HPV vaccine functioned to strengthen the national immunization program. To this end, preventing an effective problematization of the extant screening program was essential. Copyright © 2016 The Author. Published by Elsevier Ltd.. All rights reserved.

  11. New vaccine strategies against enterotoxigenic Escherichia coli: II: Enhanced systemic and secreted antibody responses against the CFA/I fimbriae by priming with DNA and boosting with a live recombinant Salmonella vaccine

    Directory of Open Access Journals (Sweden)

    M.O. Lásaro

    1999-02-01

    Full Text Available The induction of systemic (IgG and mucosal (IgA antibody responses against the colonization factor I antigen (CFA/I of enterotoxigenic Escherichia coli (ETEC was evaluated in mice primed with an intramuscularly delivered CFA/I-encoding DNA vaccine followed by two oral immunizations with a live recombinant Salmonella typhimurium vaccine strain expressing the ETEC antigen. The booster effect induced by the oral immunization was detected two weeks and one year after the administration of the DNA vaccine. The DNA-primed/Salmonella-boosted vaccination regime showed a synergistic effect on the induced CFA/I-specific systemic and secreted antibody levels which could not be attained by either immunization strategy alone. These results suggest that the combined use of DNA vaccines and recombinant Salmonella vaccine strains can be a useful immunization strategy against enteric pathogens.

  12. Classical swine fever vaccines-State-of-the-art.

    Science.gov (United States)

    Blome, Sandra; Moß, Claudia; Reimann, Ilona; König, Patricia; Beer, Martin

    2017-07-01

    Due to its impact on animal health and pig industry, classical swine fever (CSF) is still one of the most important viral diseases of pigs. To control the disease, safe and highly efficacious live attenuated vaccines exist for decades. These vaccines have usually outstanding efficacy and safety but lack differentiability of infected from vaccinated animals (DIVA or marker strategy). In contrast, the first generation of E2 subunit marker vaccines shows constraints in efficacy, application, and production. To overcome these limitations, new generations of marker vaccines are developed. A wide range of approaches have been tried including recombinant vaccines, recombinant inactivated vaccines or subunit vaccines, vector vaccines, and DNA/RNA vaccines. During the last years, especially attenuated deletion vaccines or chimeric constructs have shown potential. At present, especially two new constructs have been intensively tested, the adenovirus-delivered, Semliki Forest virus replicon-vectored marker vaccine candidate "rAdV-SFV-E2" and the pestivirus chimera "CP7_E2alf". The later was recently licensed by the European Medicines Agency. Under field conditions, all marker vaccines have to be accompanied by a potent test system. Particularly this point shows still weaknesses and it is important to embed vaccination in a well-established vaccination strategy and a suitable diagnostic workflow. In summary, conventional vaccines are a standard in terms of efficacy. However, only vaccines with DIVA will allow improved eradication strategies e.g. also under emergency vaccination conditions in free regions. To answer this demand, new generations of marker vaccines have been developed and add now to the tool box of CSF control. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Cost-effectiveness analysis of intranasal live attenuated vaccine (LAIV versus injectable inactivated influenza vaccine (TIV for Canadian children and adolescents

    Directory of Open Access Journals (Sweden)

    Tarride JE

    2012-10-01

    Full Text Available Jean-Eric Tarride,1,2 Natasha Burke,1,2 Camilla Von Keyserlingk,1,2 Daria O'Reilly,1,2 Feng Xie,1,2 Ron Goeree1,21Programs for Assessment of Technology in Health (PATH Research Institute, St Joseph's Healthcare Hamilton, Hamilton, 2Department of Clinical Epidemiology and Biostatistics, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, CanadaBackground: Influenza affects all age groups and is common in children. Between 15% and 42% of preschool- and school-aged children experience influenza each season. Recently, intranasal live attenuated influenza vaccine, trivalent (LAIV has been approved in Canada.Objective: The objective of this study was to determine the cost-effectiveness of LAIV compared with that of the injectable inactivated influenza vaccine, trivalent (TIV in Canadian children and adolescents from both a payer (eg. Ministry of Health perspective and a societal perspective.Methods: A cost-effectiveness model comparing LAIV and TIV in children aged 24–59 months old was supplemented by primary (ie, a survey of 144 Canadian physicians and secondary (eg, literature data to model children aged 2–17 years old. Parameter uncertainty was addressed through univariate and probability analyses.Results: Although LAIV increased vaccination costs when compared to TIV, LAIV reduced the number of influenza cases and lowered the number of hospitalizations, emergency room visits, outpatient visits, and parents’ days lost from work. The estimated offsets in direct and societal costs saved were CAD$4.20 and CAD$35.34, respectively, per vaccinated child aged 2–17 years old. When costs and outcomes were considered, LAIV when compared to TIV, was the dominant strategy. At a willingness to pay of CAD$50,000 per quality adjusted life year gained, or CAD$100,000 per quality adjusted life year gained, the probabilistic results indicated that the probability of LAIV being cost-effective was almost 1.Conclusions: LAIV reduces the burden

  14. Two studies evaluating the safety and immunogenicity of a live, attenuated Shigella flexneri 2a vaccine (SC602) and excretion of vaccine organisms in North American volunteers.

    Science.gov (United States)

    Katz, David E; Coster, Trinka S; Wolf, Marcia K; Trespalacios, Fernando C; Cohen, Dani; Robins, Guy; Hartman, Antoinette B; Venkatesan, Malabi M; Taylor, David N; Hale, Thomas L

    2004-02-01

    We report the first community-based evaluation of Shigella flexneri 2a strain SC602, a live, oral vaccine strain attenuated by deletion of the icsA (virG) plasmid virulence gene, given at 10(4) CFU. The primary objectives of this trial were to determine the safety and immunogenicity of the vaccine and to determine the duration of colonization. Four of 34 volunteers experienced transient fevers, and three reported diarrhea during the first 3 days of the study. Half of the volunteers mounted a positive serum immunoglobulin A (IgA) response to S. flexneri lipopolysaccharide. All but one of the volunteers excreted the vaccine in their stools for 1 to 33 days, and this excretion was often intermittent. Data from the community-based study were supplemented with an inpatient trial in which three volunteers received 10(3) and nine received 10(4) CFU. All volunteers who received 10(3) CFU excreted SC602 and had an IgA antibody-secreting cell response. Two of these had a serum IgA response. Six of the nine volunteers who received 10(4) CFU excreted SC602. One vaccinee had a transient fever and two met the definition of diarrhea. Six volunteers that received 10(4) CFU had an antibody-secreting cell response, and four had a serum IgA response. SC602 has now been tested at 10(4) CFU in a total of 58 volunteers. The cumulative results of these clinical trials, reported here and previously (Coster et al., Infect. Immun. 67:3437-3443, 1999), have demonstrated that SC602 is a substantially attenuated candidate vaccine that can evoke protection against the most severe symptoms of shigellosis in a stringent human challenge model of disease.

  15. Immunization with a Novel Human type 5 Adenovirus-Vectored Vaccine Expressing the Premembrane and Envelope Proteins of Zika Virus Provides Consistent and Sterilizing Protection in Multiple Immunocompetent and Immunocompromised Animal Models.

    Science.gov (United States)

    Guo, Qiang; Chan, Jasper Fuk-Woo; Poon, Vincent Kwok-Man; Wu, Shipo; Chan, Chris Chung-Sing; Hou, Lihua; Yip, Cyril Chik-Yan; Ren, Changpeng; Cai, Jian-Piao; Zhao, Mengsu; Zhang, Anna Jinxia; Song, Xiaohong; Chan, Kwok-Hung; Wang, Busen; Kok, Kin-Hang; Wen, Yanbo; Yuen, Kwok-Yung; Chen, Wei

    2018-03-29

    Zika virus (ZIKV) infection may be associated with severe complications and disseminated via both vector-borne and non-vector-borne routes. Adenovirus-vectored vaccines represent a favorable controlling measure for the ZIKV epidemic as they have been shown to be safe, immunogenic, and rapidly generable for other emerging viral infections. Evaluations of two previously reported adenovirus-vectored ZIKV vaccines were performed using non-lethal animal models and/or non-epidemic ZIKV strain. We constructed and evaluated two human adenovirus-5-vectored vaccines containing the ZIKV premembrane-envelope(Ad5-Sig-prM-Env) and envelope(Ad5-Env) proteins, respectively, in multiple non-lethal and lethal animal models using epidemic ZIKV strains. Both vaccines elicited robust humoral and cellular immune responses in immunocompetent BALB/c mice. Dexamethasone-immunosuppressed mice vaccinated with either vaccine demonstrated robust and durable antibody responses and significantly lower blood/tissue viral loads than controls(Panimal models, Ad5-Sig-prM-Env-vaccinated mice had significantly(P<0.05) higher titers of anti-ZIKV-specific neutralizing antibody titers and lower(undetectable) viral loads than Ad5-Env-vaccinated mice. The close correlation between the neutralizing antibody titer and viral load helped to explain the better protective effect of Ad5-Sig-prM-Env than Ad5-Env. Anamnestic response was absent in Ad5-Sig-prM-Env-vaccinated A129 mice. Ad5-Sig-prM-Env provided sterilizing protection against ZIKV infection in mice.

  16. Immune responses and interactions following simultaneous application of live Newcastle disease, infectious bronchitis and avian metapneumovirus vaccines in specific-pathogen-free chicks.

    Science.gov (United States)

    Awad, Faez; Forrester, Anne; Baylis, Matthew; Lemiere, Stephane; Jones, Richard; Ganapathy, Kannan

    2015-02-01

    Interactions between live Newcastle disease virus (NDV), avian metapneumovirus (aMPV) and infectious bronchitis virus (IBV) vaccines following simultaneous vaccination of day old specific pathogen free (SPF) chicks were evaluated. The chicks were divided into eight groups: seven vaccinated against NDV, aMPV and IBV (single, dual or triple) and one unvaccinated as control. Haemagglutination inhibition (HI) NDV antibody titres were similar across all groups but were above protective titres. aMPV vaccine when given with other live vaccines suppressed levels of aMPV enzyme-linked immunosorbent assay (ELISA) antibodies. Cellular and local immunity induced by administration of NDV, aMPV or IBV vaccines (individually or together) showed significant increase in CD4+, CD8+ and IgA bearing B-cells in the trachea compared to the unvaccinated group. Differences between the vaccinated groups were insignificant. Simultaneous vaccination with live NDV, aMPV and IBV did not affect the protection conferred against aMPV or IBV. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Early protection events in swine immunized with an experimental live attenuated classical swine fever marker vaccine, FlagT4G.

    Directory of Open Access Journals (Sweden)

    Lauren G Holinka

    Full Text Available Prophylactic vaccination using live attenuated classical swine fever (CSF vaccines has been a very effective method to control the disease in endemic regions and during outbreaks in previously disease-free areas. These vaccines confer effective protection against the disease at early times post-vaccination although the mechanisms mediating the protection are poorly characterized. Here we present the events occurring after the administration of our in-house developed live attenuated marker vaccine, FlagT4Gv. We previously reported that FlagT4Gv intramuscular (IM administered conferred effective protection against intranasal challenge with virulent CSFV (BICv as early as 7 days post-vaccination. Here we report that FlagT4Gv is able to induce protection against disease as early as three days post-vaccination. Immunohistochemical testing of tissues from FlagT4Gv-inoculated animals showed that tonsils were colonized by the vaccine virus by day 3 post-inoculation. There was a complete absence of BICv in tonsils of FlagT4Gv-inoculated animals which had been intranasal (IN challenged with BICv 3 days after FlagT4Gv infection, confirming that FlagT4Gv inoculation confers sterile immunity. Analysis of systemic levels of 19 different cytokines in vaccinated animals demonstrated an increase of IFN-α three days after FlagT4Gv inoculation compared with mock infected controls.

  18. Seroprevalence of fowl pox antibody in indigenous chickens in jos north and South council areas of plateau state, Nigeria: implication for vector vaccine.

    Science.gov (United States)

    Adebajo, Meseko Clement; Ademola, Shittu Ismail; Oluwaseun, Akinyede

    2012-01-01

    Fowl pox is a viral disease of domestic and wild birds. The large size of the genome makes it a useful vector for recombinant DNA technology. Although the disease has been described in both commercial and indigenous chickens in Nigeria, data are limited on seroprevalence in free range chickens. Such data are, however, important in the design and implementation of fowl pox virus vector vaccine. We surveyed current antibody status to fowl pox virus in free range chickens by testing 229 sera collected from 10 villages in Jos North and Jos South LGA of Plateau State Nigeria. Sera were analyzed by AGID against standard fowl pox antigen. Fifty-two of the 229 (23%) tested sera were positive for fowl pox virus antibody, and the log titre in all positive specimen was >2. Thirty (21%) and twenty-two (27%) of the samples from Jos South and Jos North, respectively, tested positive. This was, however, not statistically significant (P = 0.30). Generally the study showed a significant level of antibody to fowl pox virus in the study area. This observation may hinder effective use of fowl pox vectored viral vaccine. Fowl pox control is recommended to reduce natural burden of the disease.

  19. Horizontal transmission of the Leningrad-3 live attenuated mumps vaccine virus.

    Science.gov (United States)

    Atrasheuskaya, A V; Neverov, A A; Rubin, S; Ignatyev, G M

    2006-03-06

    Here we describe symptomatic transmission of the Leningrad-3 mumps vaccine virus from healthy vaccinees to previously vaccinated contacts. Throat swab and serum samples were taken from six symptomatic mumps cases and from 13 family contacts. Assessment of serum IgG and IgM anti-mumps virus antibodies and IgG avidity testing was performed using commercial test kits. Sera neutralizing antibodies were measured by plaque reduction neutralization assay using the L-3 vaccine mumps virus as the target. All six of the symptomatic mumps cases and three contact subjects tested positive for mumps by RT-PCR. The genomic sequences tested (F, SH and HN genes) of all nine of these samples were identical to the L-3 mumps vaccine strain. All 13 contacts were asymptomatic; however clear serological evidence of mumps infection was found in some of them. The likely epidemiological source of the transmitted L-3 mumps virus was children who were recently vaccinated at the schools attended by the six symptomatic mumps patients described here. The L-3 mumps vaccine virus can be shed and transmitted horizontally, even to subjects previously vaccinated with the same virus.

  20. A phase I double blind, placebo-controlled, randomized study of a multigenic HIV-1 adenovirus subtype 35 vector vaccine in healthy uninfected adults.

    Directory of Open Access Journals (Sweden)

    Michael C Keefer

    Full Text Available We conducted a phase I, randomized, double-blind, placebo-controlled trial to assess the safety and immunogenicity of escalating doses of two recombinant replication defective adenovirus serotype 35 (Ad35 vectors containing gag, reverse transcriptase, integrase and nef (Ad35-GRIN and env (Ad35-ENV, both derived from HIV-1 subtype A isolates. The trial enrolled 56 healthy HIV-uninfected adults.Ad35-GRIN/ENV (Ad35-GRIN and Ad35-ENV mixed in the same vial in equal proportions or Ad35-GRIN was administered intramuscularly at 0 and 6 months. Participants were randomized to receive either vaccine or placebo (10/4 per group, respectively within one of four dosage groups: Ad35-GRIN/ENV 2×10(9 (A, 2×10(10 (B, 2×10(11 (C, or Ad35-GRIN 1×10(10 (D viral particles.No vaccine-related serious adverse event was reported. Reactogenicity events reported were dose-dependent, mostly mild or moderate, some severe in Group C volunteers, all transient and resolving spontaneously. IFN-γ ELISPOT responses to any vaccine antigen were detected in 50, 56, 70 and 90% after the first vaccination, and in 75, 100, 88 and 86% of Groups A-D vaccine recipients after the second vaccination, respectively. The median spot forming cells (SFC per 10(6 PBMC to any antigen was 78-139 across Groups A-C and 158-174 in Group D, after each of the vaccinations with a maximum of 2991 SFC. Four to five HIV proteins were commonly recognized across all the groups and over multiple timepoints. CD4+ and CD8+ T-cell responses were polyfunctional. Env antibodies were detected in all Group A-C vaccinees and Gag antibodies in most vaccinees after the second immunization. Ad35 neutralizing titers remained low after the second vaccination.Ad35-GRIN/ENV reactogenicity was dose-related. HIV-specific cellular and humoral responses were seen in the majority of volunteers immunized with Ad35-GRIN/ENV or Ad35-GRIN and increased after the second vaccination. T-cell responses were broad and polyfunctional

  1. Firewalls Prevent Systemic Dissemination of Vectors Derived from Human Adenovirus Type 5 and Suppress Production of Transgene-Encoded Antigen in a Murine Model of Oral Vaccination.

    Science.gov (United States)

    Revaud, Julien; Unterfinger, Yves; Rol, Nicolas; Suleman, Muhammad; Shaw, Julia; Galea, Sandra; Gavard, Françoise; Lacour, Sandrine A; Coulpier, Muriel; Versillé, Nicolas; Havenga, Menzo; Klonjkowski, Bernard; Zanella, Gina; Biacchesi, Stéphane; Cordonnier, Nathalie; Corthésy, Blaise; Ben Arous, Juliette; Richardson, Jennifer P

    2018-01-01

    To define the bottlenecks that restrict antigen expression after oral administration of viral-vectored vaccines, we tracked vectors derived from the human adenovirus type 5 at whole body, tissue, and cellular scales throughout the digestive tract in a murine model of oral delivery. After intragastric administration of vectors encoding firefly luciferase or a model antigen, detectable levels of transgene-encoded protein or mRNA were confined to the intestine, and restricted to delimited anatomical zones. Expression of luciferase in the form of multiple small bioluminescent foci in the distal ileum, cecum, and proximal colon suggested multiple crossing points. Many foci were unassociated with visible Peyer's patches, implying that transduced cells lay in proximity to villous rather than follicle-associated epithelium, as supported by detection of transgene-encoded antigen in villous epithelial cells. Transgene-encoded mRNA but not protein was readily detected in Peyer's patches, suggesting that post-transcriptional regulation of viral gene expression might limit expression of transgene-encoded antigen in this tissue. To characterize the pathways by which the vector crossed the intestinal epithelium and encountered sentinel cells, a fluorescent-labeled vector was administered to mice by the intragastric route or inoculated into ligated intestinal loops comprising a Peyer's patch. The vector adhered selectively to microfold cells in the follicle-associated epithelium, and, after translocation to the subepithelial dome region, was captured by phagocytes that expressed CD11c and lysozyme. In conclusion, although a large number of crossing events took place throughout the intestine within and without Peyer's patches, multiple firewalls prevented systemic dissemination of vector and suppressed production of transgene-encoded protein in Peyer's patches.

  2. Firewalls Prevent Systemic Dissemination of Vectors Derived from Human Adenovirus Type 5 and Suppress Production of Transgene-Encoded Antigen in a Murine Model of Oral Vaccination

    Directory of Open Access Journals (Sweden)

    Julien Revaud

    2018-01-01

    Full Text Available To define the bottlenecks that restrict antigen expression after oral administration of viral-vectored vaccines, we tracked vectors derived from the human adenovirus type 5 at whole body, tissue, and cellular scales throughout the digestive tract in a murine model of oral delivery. After intragastric administration of vectors encoding firefly luciferase or a model antigen, detectable levels of transgene-encoded protein or mRNA were confined to the intestine, and restricted to delimited anatomical zones. Expression of luciferase in the form of multiple small bioluminescent foci in the distal ileum, cecum, and proximal colon suggested multiple crossing points. Many foci were unassociated with visible Peyer's patches, implying that transduced cells lay in proximity to villous rather than follicle-associated epithelium, as supported by detection of transgene-encoded antigen in villous epithelial cells. Transgene-encoded mRNA but not protein was readily detected in Peyer's patches, suggesting that post-transcriptional regulation of viral gene expression might limit expression of transgene-encoded antigen in this tissue. To characterize the pathways by which the vector crossed the intestinal epithelium and encountered sentinel cells, a fluorescent-labeled vector was administered to mice by the intragastric route or inoculated into ligated intestinal loops comprising a Peyer's patch. The vector adhered selectively to microfold cells in the follicle-associated epithelium, and, after translocation to the subepithelial dome region, was captured by phagocytes that expressed CD11c and lysozyme. In conclusion, although a large number of crossing events took place throughout the intestine within and without Peyer's patches, multiple firewalls prevented systemic dissemination of vector and suppressed production of transgene-encoded protein in Peyer's patches.

  3. Tularemia vaccine: Safety, reactogenicity, "Take" skin reactions, and antibody responses following vaccination with a new lot of the Francisella tularensis live vaccine strain - A phase 2 randomized clinical Trial.

    Science.gov (United States)

    Mulligan, Mark J; Stapleton, Jack T; Keitel, Wendy A; Frey, Sharon E; Chen, Wilbur H; Rouphael, Nadine; Edupuganti, Srilatha; Beck, Allison; Winokur, Patricia L; El Sahly, Hana M; Patel, Shital M; Atmar, Robert L; Graham, Irene; Anderson, Edwin; El-Kamary, Samer S; Pasetti, Marcela F; Sztein, Marcelo B; Hill, Heather; Goll, Johannes B

    2017-08-24

    Tularemia is caused by Francisella tularensis, a gram-negative bacterium that has been weaponized as an aerosol. For protection of personnel conducting biodefense research, the United States Army required clinical evaluation of a new lot of tularemia live vaccine strain manufactured in accordance with Current Good Manufacturing Practices. A phase 2 randomized clinical trial compared the new lot (DVC-LVS) to the existing vaccine that has been in use for decades (USAMRIID-LVS). The vaccines were delivered by scarification to 228 participants. Safety, reactogenicity, take and/or antibody levels were assessed on days 0, 1, 2, 8, 14, 28, 56, and 180. Both vaccines were safe and had acceptable reactogenicity profiles during six months of follow-up. There were no serious or grade 3 and 4 laboratory adverse events. Moderate systemic reactogenicity (mostly headache or feeling tired) was reported by ∼23% of participants receiving either vaccine. Injection site reactogenicity was mostly mild itchiness and pain. The frequencies of vaccine take skin reactions were 73% (95% CI, 64, 81) for DVC-LVS and 80% (95% CI, 71, 87) for USAMRIID-LVS. The 90% CI for the difference in proportions was -6.9% (-16.4, 2.6). The rates of seroconversion measured by microagglutination assay on days 28 or 56 were 94% (95% CI, 88, 98; n=98/104) for DVC-LVS and 94% (95% CI, 87, 97; n=103/110) for USAMRIID-LVS (p=1.00). Day 14 sera revealed more rapid seroconversion for DVC-LVS relative to USAMRIID-LVS: 82% (95% CI, 73, 89) versus 55% (95% CI, 45, 65), respectively (p<0.0001). The DVC-LVS vaccine had similar safety, reactogenicity, take and antibody responses compared to the older USAMRIID vaccine, and was superior for early (day 14) antibody production. Vaccination take was not a sensitive surrogate for seroconversion in a multi-center study where personnel at five research clinics performed assessments. ClinicalTrials.gov identifier NCT01150695. Copyright © 2017 The Authors. Published by Elsevier

  4. Need for a safe vaccine against respiratory syncytial virus infection

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    Joo-Young Kim

    2012-09-01

    Full Text Available Human respiratory syncytial virus (HRSV is a major cause of severe respiratory tract illnesses in infants and young children worldwide. Despite its importance as a respiratory pathogen, there is currently no licensed vaccine for HRSV. Following failure of the initial trial of formalin-inactivated virus particle vaccine, continuous efforts have been made for the development of safe and efficacious vaccines against HRSV. However, several obstacles persist that delay the development of HRSV vaccine, such as the immature immune system of newborn infants and the possible Th2-biased immune responses leading to subsequent vaccine-enhanced diseases. Many HRSV vaccine strategies are currently being developed and evaluated, including live-attenuated viruses, subunit-based, and vector-based candidates. In this review, the current HRSV vaccines are overviewed and the safety issues regarding asthma and vaccine-induced pathology are discussed.

  5. Microneedle Array Design Determines the Induction of Protective Memory CD8+ T Cell Responses Induced by a Recombinant Live Malaria Vaccine in Mice

    Science.gov (United States)

    Carey, John B.; Pearson, Frances E.; Vrdoljak, Anto; McGrath, Marie G.; Crean, Abina M.; Walsh, Patrick T.; Doody, Timothy; O'Mahony, Conor; Hill, Adrian V. S.; Moore, Anne C.

    2011-01-01

    Background Vaccine delivery into the skin has received renewed interest due to ease of access to the immune system and microvasculature, however the stratum corneum (SC), must be breached for successful vaccination. This has been achieved by removing the SC by abrasion or scarification or by delivering the vaccine intradermally (ID) with traditional needle-and-syringes or with long microneedle devices. Microneedle patch-based transdermal vaccine studies have predominantly focused on antibody induction by inactivated or subunit vaccines. Here, our principal aim is to determine if the design of a microneedle patch affects the CD8+ T cell responses to a malaria antigen induced by a live vaccine. Methodology and Findings Recombinant modified vaccinia virus Ankara (MVA) expressing a malaria antigen was percutaneously administered to mice using a range of silicon microneedle patches, termed ImmuPatch, that differed in microneedle height, density, patch area and total pore volume. We demonstrate that microneedle arrays that have small total pore volumes induce a significantly greater proportion of central memory T cells that vigorously expand to secondary immunization. Microneedle-mediated vaccine priming induced significantly greater T cell immunity post-boost and equivalent protection against malaria challenge compared to ID vaccination. Notably, unlike ID administration, ImmuPatch-mediated vaccination did not induce inflammatory responses at the site of immunization or in draining lymph nodes. Conclusions/Significance This study demonstrates that the design of microneedle patches significantly influences the magnitude and memory of vaccine-induced CD8+ T cell responses and can be optimised for the induction of desired immune responses. Furthermore, ImmuPatch-mediated delivery may be of benefit to reducing unwanted vaccine reactogenicity. In addition to the advantages of low cost and lack of pain, the development of optimised microneedle array designs for the induction

  6. Microneedle array design determines the induction of protective memory CD8+ T cell responses induced by a recombinant live malaria vaccine in mice.

    Directory of Open Access Journals (Sweden)

    John B Carey

    Full Text Available Vaccine delivery into the skin has received renewed interest due to ease of access to the immune system and microvasculature, however the stratum corneum (SC, must be breached for successful vaccination. This has been achieved by removing the SC by abrasion or scarification or by delivering the vaccine intradermally (ID with traditional needle-and-syringes or with long microneedle devices. Microneedle patch-based transdermal vaccine studies have predominantly focused on antibody induction by inactivated or subunit vaccines. Here, our principal aim is to determine if the design of a microneedle patch affects the CD8(+ T cell responses to a malaria antigen induced by a live