WorldWideScience

Sample records for attenuated vaccine development

  1. Rationalizing the development of live attenuated virus vaccines

    OpenAIRE

    Lauring, Adam S.; Jones, Jeremy O.; Andino, Raul

    2010-01-01

    Since the first demonstration of the protective effects of vaccinia inoculation, vaccination has been one of the medicine’s greatest successes. The design of vaccines against viral disease has evolved considerably over the last 50 years. Classically attenuated viruses, those created by passaging a virus in cultured cells, have proven to be an effective means for preventing many viral diseases, including smallpox, polio, measles, mumps, and yellow fever. However, empiric attenuation is not a r...

  2. New approaches to the development of live attenuated rabies vaccines.

    Science.gov (United States)

    Dietzschold, Bernhard; Schnell, Matthias J

    2002-04-01

    In the United States, extensive reservoirs of the rabies virus exist in many diverse wild animal species, which continue to pose a serious risk of lethal infection of humans and cause an economic burden exceeding $1 billion annually. Previous experience with rabies control in foxes in Europe has clearly demonstrated that oral immunization with live vaccines is the only practical approach to eradicate rabies in free-ranging animals. However, unlike Europe where vulpine rabies was the only major reservoir, the Americas harbor a variety of species including raccoons, skunks, coyotes, and bats that serve as the primary reservoirs of rabies. Each of these animal reservoirs carries an antigenically distinct virus variant. The currently available modified-live rabies virus vaccines have either safety problems or do not induce sufficient protective immunity in particular wildlife species. Therefore, there is a need for the development of new live rabies virus vaccines that are very safe and highly effective in particular wildlife species. Based on previous observations indicating that the potency of a vaccine is significantly increased if the G protein of the vaccine strain is identical to that of the target virus, we have used a reverse genetics approach to engineer viruses that contain G proteins from virus strains associated with relevant wildlife species. Furthermore, because our recent data also indicate that the pathogenicity of a particular rabies virus strain is inversely proportional to its ability to induce apoptosis and that low-level apoptosis-inducing ability is associated with low anti-viral immune responses, we inserted genes encoding pro-apoptotic proteins to stimulate immunity or otherwise interfere with viral pathogenesis into these recombinant viruses to enhance their efficacy and safety. PMID:12031103

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

    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...

  4. 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...

  5. Development of a stable liquid formulation of live attenuated influenza vaccine.

    Science.gov (United States)

    White, Jessica A; Estrada, Marcus; Flood, E Alexander; Mahmood, Kutub; Dhere, Rajeev; Chen, Dexiang

    2016-07-12

    Vaccination is the most effective means of preventing influenza. However, the cost of producing annual seasonal influenza vaccines puts them out of reach for most developing countries. While live attenuated influenza vaccines are among the most efficacious and can be manufactured at low cost, they may require lyophilization to be stable enough for developing-country use, which adds a significant cost burden. The development of a liquid live attenuated seasonal influenza vaccine that is stable for around a year-the duration of an annual influenza season-would significantly improve not only the production output but also the use and accessibility of influenza vaccines in low-resource settings. In this study, potential stabilizing excipients were screened and optimized using the least stable influenza vaccine strain presently known, H1N1 (A/California/07/2009), as a model. The stability-conferring properties of the lead formulations were also tested with a Type B strain of influenza virus (B/Brisbane/60/2008). Stability was also evaluated with higher titers of influenza virus and exposure to agitation and freeze-thaw stresses to further confirm the stability of the lead formulations. Through this process, we identified a liquid formulation consisting of sucrose phosphate glutamate buffer with 1% arginine and 0.5% recombinant human serum albumin that provided storage stability of one year at 2-8°C for the influenza A and B strains tested. PMID:27155495

  6. Reverse genetics of rabies virus: new strategies to attenuate virus virulence for vaccine development.

    Science.gov (United States)

    Zhu, Shimao; Li, Hui; Wang, Chunhua; Luo, Farui; Guo, Caiping

    2015-08-01

    Rabies is an ancient neurological disease that is almost invariably fatal once the clinical symptoms develop. Currently, prompt wound cleansing after exposing to a potentially rabid animal and vaccination using rabies vaccine combined with administration of rabies immune globulin are the only effective methods for post-exposure prophylaxis against rabies. Reverse genetic technique is a novel approach to investigate the function of a specific gene by analyzing the phenotypic effects through directly manipulating the gene sequences. It has revolutionized and provided a powerful tool to study the molecular biology of RNA viruses and has been widely used in rabies virus research. The attenuation of rabies virus virulence is the prerequisite for rabies vaccine development. Given the current challenge that sufficient and affordable high-quality vaccines are limited and lacking for global rabies prevention and control, highly cell-adapted, stable, and attenuated rabies viruses with broad cross-reactivity against different viral variants are ideal candidates for consideration to meet the need for human rabies control in the future. A number of approaches have been pursued to reduce the virulence of the virus and improve the safety of rabies vaccines. The application of reverse genetic technique has greatly advanced the engineering of rabies virus and paves the avenue for utilizing rabies virus for vaccine against rabies, viral vectors for exogenous antigen expression, and gene therapy in the future. PMID:25994916

  7. Brucellosis: The Case for Live, Attenuated Vaccines

    OpenAIRE

    Ficht, Thomas A.; Kahl-McDonagh, Melissa M.; Arenas-Gamboa, Angela M.; Rice-Ficht, Allison C.

    2009-01-01

    The successful control of animal brucellosis and associated reduction in human exposure has limited the development of human brucellosis vaccines. However, the potential use of Brucella in bioterrorism or biowarfare suggests that direct intervention strategies are warranted. Although the dominant approach has explored the use of live attenuated vaccines, side-effects associated with their use has prevented widespread use in humans. Development of live, attenuated Brucella vaccines that are sa...

  8. Radiation-attenuated vaccine for lungworm disease

    International Nuclear Information System (INIS)

    The work done at the Indian Veternary Research Institute, Izatnagar, on the development of a vaccine for lungworm diseases is reported. Research work done includes: (1) studies on the epidemiology and the incidence of the lungworm infections, (ii) studies on the radiation-attenuated lungworm Dictyocaulus filaria vaccine, (iii) studies on other parasites using ionizing radiation, (iv) incidence of lungworm infection in sheep in Jammu and Kashmir State, (v) suitable dose of gamma radiation for attenuation, (vi) laboratory studies with radiation-attenuated D. filaria vaccine, (vii) serology of D. filaria infection, (viii) field trials with the radiation-attenuated vaccine, (ix) immune response of previously exposed lambs to vaccination, (x) comparative susceptibility of sheep and goats to infection with D. filaria, (xi) quantitative studies of D. filaria in lambs and (xii) production and supply of lungworm vaccine. (A.K.)

  9. A pilot study comparing the development of EIAV Env-specific antibodies induced by DNA/recombinant vaccinia-vectored vaccines and an attenuated Chinese EIAV vaccine.

    Science.gov (United States)

    Meng, Qinglai; Lin, Yuezhi; Ma, Jian; Ma, Yan; Zhao, Liping; Li, Shenwei; Yang, Kai; Zhou, Jianhua; Shen, Rongxian; Zhang, Xiaoyan; Shao, Yiming

    2012-12-01

    Data from successful attenuated lentiviral vaccine studies indicate that fully mature Env-specific antibodies characterized by high titer, high avidity, and the predominant recognition of conformational epitopes are associated with protective efficacy. Although vaccination with a DNA prime/recombinant vaccinia-vectored vaccine boost strategy has been found to be effective in some trials with non-human primate/simian/human immunodeficiency virus (SHIV) models, it remains unclear whether this vaccination strategy could elicit mature equine infectious anemia virus (EIAV) Env-specific antibodies, thus protecting vaccinated horses against EIAV infection. Therefore, in this pilot study we vaccinated horses using a strategy based on DNA prime/recombinant Tiantan vaccinia (rTTV)-vectored vaccines encoding EIAV env and gag genes, and observed the development of Env-specific antibodies, neutralizing antibodies, and p26-specific antibodies. Vaccination with DNA induced low titer, low avidity, and the predominant recognition of linear epitopes by Env-specific antibodies, which was enhanced by boosting vaccinations with rTTV vaccines. However, the maturation levels of Env-specific antibodies induced by the DNA/rTTV vaccines were significantly lower than those induced by the attenuated vaccine EIAV(FDDV). Additionally, DNA/rTTV vaccines did not elicit broadly neutralizing antibodies. After challenge with a virulent EIAV strain, all of the vaccinees and control horses died from EIAV disease. These data indicate that the regimen of DNA prime/rTTV vaccine boost did not induce mature Env-specific antibodies, which might have contributed to immune protection failure. PMID:23171359

  10. Rational development of an attenuated recombinant cyprinid herpesvirus 3 vaccine using prokaryotic mutagenesis and in vivo bioluminescent imaging.

    Science.gov (United States)

    Boutier, Maxime; Ronsmans, Maygane; Ouyang, Ping; Fournier, Guillaume; Reschner, Anca; Rakus, Krzysztof; Wilkie, Gavin S; Farnir, Frédéric; Bayrou, Calixte; Lieffrig, François; Li, Hong; Desmecht, Daniel; Davison, Andrew J; Vanderplasschen, Alain

    2015-02-01

    Cyprinid herpesvirus 3 (CyHV 3) is causing severe economic losses worldwide in common and koi carp industries, and a safe and efficacious attenuated vaccine compatible with mass vaccination is needed. We produced single deleted recombinants using prokaryotic mutagenesis. When producing a recombinant lacking open reading frame 134 (ORF134), we unexpectedly obtained a clone with additional deletion of ORF56 and ORF57. This triple deleted recombinant replicated efficiently in vitro and expressed an in vivo safety/efficacy profile compatible with use as an attenuated vaccine. To determine the role of the double ORF56-57 deletion in the phenotype and to improve further the quality of the vaccine candidate, a series of deleted recombinants was produced and tested in vivo. These experiments led to the selection of a double deleted recombinant lacking ORF56 and ORF57 as a vaccine candidate. The safety and efficacy of this strain were studied using an in vivo bioluminescent imaging system (IVIS), qPCR, and histopathological examination, which demonstrated that it enters fish via skin infection similar to the wild type strain. However, compared to the parental wild type strain, the vaccine candidate replicated at lower levels and spread less efficiently to secondary sites of infection. Transmission experiments allowing water contamination with or without additional physical contact between fish demonstrated that the vaccine candidate has a reduced ability to spread from vaccinated fish to naïve sentinel cohabitants. Finally, IVIS analyses demonstrated that the vaccine candidate induces a protective mucosal immune response at the portal of entry. Thus, the present study is the first to report the rational development of a recombinant attenuated vaccine against CyHV 3 for mass vaccination of carp. We also demonstrated the relevance of the CyHV 3 carp model for studying alloherpesvirus transmission and mucosal immunity in teleost skin. PMID:25700279

  11. Development of radiation attenuated antiparasitic vaccines and their impact on control of livestock diseases in India- a review

    International Nuclear Information System (INIS)

    The development of the first antiparasitic D. filaria vaccine in India, its impact upon the control of lung worm infections in enzootic areas besides the work done on immunological control of parasitic infections of animals, using radiation attenuated infective stages of the parasites as immunogens and future prospects of such crude antigens as vaccine and their application in control of parasitic diseases vis-a-vis increased animal productivity are traced in this review. 16 refs., 1 tab

  12. Development and efficacy of an attenuated Vibrio harveyi vaccine candidate with cross protectivity against Vibrio alginolyticus.

    Science.gov (United States)

    Hu, Yong-hua; Deng, Tian; Sun, Bo-guang; Sun, Li

    2012-06-01

    Vibrio harveyi is a Gram-negative bacterial pathogen that can infect a wide range of marine animals. In previous studies, we have reported a virulent V. harveyi strain, T4D. In the present study, an attenuated mutant of T4D, T4DM, was obtained by selection of rifampicin resistance. Compared to the wild type, T4DM was different in whole-cell protein profile and much slower in growth rate when cultured in stress conditions caused by iron depletion. Virulence analysis showed that compared to T4D, T4DM exhibited a dramatically increased median lethal dose, impaired tissue dissemination capacity, defective hemolytic activity, and significantly reduced resistance against the killing effect of host serum. To examine the potential of T4DM as a live attenuated vaccine, Japanese flounder (Paralichthys olivaceus) were vaccinated with T4DM via intraperitoneal injection or immersion. The results showed that at one and two months post-vaccination, fish administered with T4DM via both approaches, in particular that of immersion, were effectively protected against not only V. harveyi but also Vibrio alginolyticus, another important fish pathogen. Microbiological analysis showed that following immersion vaccination, T4DM was recovered from the internal organs of the vaccinated fish in a time-dependent manner within the first 6 days post-vaccination. Serum antibodies against V. harveyi and V. alginolyticus were detected in T4DM-vaccinated fish, and, compared to serum from control fish, serum from T4DM-vaccinated fish was significantly enhanced in bactericidal activity. These results indicate that T4DM is an attenuated strain with residual infectivity and that T4DM can induce effective cross-species protection against both V. harveyi and V. alginolyticus when used as a live immersion vaccine. PMID:22484605

  13. Attempt to develop live attenuated bacterial vaccines by selecting resistance to gossypol, proflavine hemisulfate, novobiocin, or ciprofloxacin

    Science.gov (United States)

    In an attempt to develop attenuated bacteria as potential live vaccines, four chemicals (gossypol, proflavine hemisulfate, novobiocin, and ciprofloxacin) were used to modify the following four genera of bacteria through chemical-resistance strategy: (1) Aeromonas hydrophila (9 isolates); (2) Edwards...

  14. [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

  15. Chikungunya vaccines in development.

    Science.gov (United States)

    Schwameis, Michael; Buchtele, Nina; Wadowski, Patricia Pia; Schoergenhofer, Christian; Jilma, Bernd

    2016-03-01

    Chikungunya virus has become a global health threat, spreading to the industrial world of Europe and the Americas; no treatment or prophylactic vaccine is available. Since the late 1960s much effort has been put into the development of a vaccine, and several heterogeneous strategies have already been explored. Only two candidates have recently qualified to enter clinical phase II trials, a chikungunya virus-like particle-based vaccine and a recombinant live attenuated measles virus-vectored vaccine. This review focuses on the current status of vaccine development against chikungunya virus in humans and discusses the diversity of immunization strategies, results of recent human trials and promising vaccine candidates. PMID:26554522

  16. DNA-launched live-attenuated vaccines for biodefense applications.

    Science.gov (United States)

    Pushko, Peter; Lukashevich, Igor S; Weaver, Scott C; Tretyakova, Irina

    2016-09-01

    A novel vaccine platform uses DNA immunization to launch live-attenuated virus vaccines in vivo. This technology has been applied for vaccine development against positive-strand RNA viruses with global public health impact including alphaviruses and flaviviruses. The DNA-launched vaccine represents the recombinant plasmid that encodes the full-length genomic RNA of live-attenuated virus downstream from a eukaryotic promoter. When administered in vivo, the genomic RNA of live-attenuated virus is transcribed. The RNA initiates limited replication of a genetically defined, live-attenuated vaccine virus in the tissues of the vaccine recipient, thereby inducing a protective immune response. This platform combines the strengths of reverse genetics, DNA immunization and the advantages of live-attenuated vaccines, resulting in a reduced chance of genetic reversions, increased safety, and improved immunization. With this vaccine technology, the field of DNA vaccines is expanded from those that express subunit antigens to include a novel type of DNA vaccines that launch live-attenuated viruses. PMID:27055100

  17. Development of a live attenuated antigenic marker classical swine fever vaccine

    Science.gov (United States)

    Classical Swine Fever, caused by Classical Swine Fever Virus (CSFV), is a highly contagious disease affecting swine worldwide. The two main strategies for disease control are prophylactic vaccination and non-vaccination “stamping out” policies. In a vaccination-to-live strategy, marker vaccines coul...

  18. Towards development of stable formulations of a live attenuated bacterial vaccine: a preformulation study facilitated by a biophysical approach.

    Science.gov (United States)

    Zeng, Yuhong; Fan, Haihong; Chiueh, Gary; Pham, Binh; Martin, Russ; Lechuga-Ballesteros, David; Truong, Vu L; Joshi, Sangeeta B; Middaugh, C Russell

    2009-05-01

    Development of optimal formulation conditions stabilizing live attenuated bacterial vaccines is impeded by traditional methods used for viability measurement. To facilitate preformulation studies of such vaccines, spectroscopic techniques capable of providing real-time and high throughput information have been employed to obtain a global stability profile for a live attenuated Ty21a bacterial typhoid vaccine over a wide range of pH (4 to 8) and temperature (10 to 85 degrees C). Using the data obtained from fluorescence and circular dichroism techniques, an empirical phase diagram (EPD) has been subsequently constructed, which suggests that Ty21a cells exist in at least four apparent physical phases related to different viability states, with the most stable phase at pH 6 and 7 at temperatures below 30 degrees C. A slightly basic pH (pH 8) appears to decrease the fluidity of the cell membrane, whereas acidic pH conditions are detrimental to membrane integrity over the entire temperature range. Based on the above stability profile, a fluorescence-based high throughput screening assay has been developed to test the stabilizing effects of various compounds at different concentrations. Amongst other promising stabilizers, 10% sucrose and 0.15 M glutamic acid display the greatest protective effects, with an increase of about 10 degrees C in the transition temperature of Ty21a cells. Preliminary studies have also been performed on foam dried formulations as an alternative approach to further stabilize Ty21a cells. The data show that 10% sucrose and trehalose both increase the in-process and storage stabilities of the cells. PMID:19221516

  19. 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)

    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

  20. Streptococcus iniae M-like protein contributes to virulence in fish and is a target for live attenuated vaccine development.

    Directory of Open Access Journals (Sweden)

    Jeffrey B Locke

    Full Text Available BACKGROUND: Streptococcus iniae is a significant pathogen in finfish aquaculture, though knowledge of virulence determinants is lacking. Through pyrosequencing of the S. iniae genome we have identified two gene homologues to classical surface-anchored streptococcal virulence factors: M-like protein (simA and C5a peptidase (scpI. METHODOLOGY/PRINCIPAL FINDINGS: S. iniae possesses a Mga-like locus containing simA and a divergently transcribed putative mga-like regulatory gene, mgx. In contrast to the Mga locus of group A Streptococcus (GAS, S. pyogenes, scpI is located distally in the chromosome. Comparative sequence analysis of the Mgx locus revealed only one significant variant, a strain with an insertion frameshift mutation in simA and a deletion mutation in a region downstream of mgx, generating an ORF which may encode a second putative mga-like gene, mgx2. Allelic exchange mutagenesis of simA and scpI was employed to investigate the potential role of these genes in S. iniae virulence. Our hybrid striped bass (HSB and zebrafish models of infection revealed that M-like protein contributes significantly to S. iniae pathogenesis whereas C5a peptidase-like protein does not. Further, in vitro cell-based analyses indicate that SiMA, like other M family proteins, contributes to cellular adherence and invasion and provides resistance to phagocytic killing. Attenuation in our virulence models was also observed in the S. iniae isolate possessing a natural simA mutation. Vaccination of HSB with the Delta simA mutant provided 100% protection against subsequent challenge with a lethal dose of wild-type (WT S. iniae after 1,400 degree days, and shows promise as a target for live attenuated vaccine development. CONCLUSIONS/SIGNIFICANCE: Analysis of M-like protein and C5a peptidase through allelic replacement revealed that M-like protein plays a significant role in S. iniae virulence, and the Mga-like locus, which may regulate expression of this gene, has an

  1. 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.

  2. Attenuated Measles Virus as a Vaccine Vector

    OpenAIRE

    Zuniga, Armando; Wang, Zili; Liniger, Matthias; Hangartner, Lars; Caballero, Michael; Pavlovic, Jovan; Wild, Peter; Viret, Jean Francois; Glueck, Reinhard; Billeter, Martin A.; Naim, Hussein Y.

    2007-01-01

    Live attenuated measles virus (MV) vaccines have an impressive record of safety, efficacy and ability to induce life-long immunity against measles infection. Using reverse genetics technology, such negative-strand RNA viruses can now be rescued from cloned DNA. This technology allows the insertion of exogenous genes encoding foreign antigens into the MV genome in such a way that they can be expressed by the MV vaccine strain, without affecting virus structure, propagation and cell targeting. ...

  3. Live-Attenuated Respiratory Syncytial Virus Vaccines

    OpenAIRE

    Karron, Ruth A.; Buchholz, Ursula J.; Collins, Peter L.

    2013-01-01

    Live-attenuated respiratory syncytial virus (RSV) vaccines offer several advantages for immunization of infants and young children: (1) they do not cause vaccine-associated enhanced RSV disease; (2) they broadly stimulate innate, humoral, and cellular immunity, both systemically and locally in the respiratory tract; (3) they are delivered intranasally; and (4) they replicate in the upper respiratory tract of young infants despite the presence of passively acquired maternally derived RSV neutr...

  4. Development of a dual-protective live attenuated vaccine against H5N1 and H9N2 avian influenza viruses by modifying the NS1 gene.

    Science.gov (United States)

    Choi, Eun-hye; Song, Min-Suk; Park, Su-Jin; Pascua, Philippe Noriel Q; Baek, Yun Hee; Kwon, Hyeok-il; Kim, Eun-Ha; Kim, Semi; Jang, Hyung-Kwan; Poo, Haryoung; Kim, Chul-Joong; Choi, Young Ki

    2015-07-01

    An increasing number of outbreaks of avian influenza H5N1 and H9N2 viruses in poultry have caused serious economic losses and raised concerns for human health due to the risk of zoonotic transmission. However, licensed H5N1 and H9N2 vaccines for animals and humans have not been developed. Thus, to develop a dual H5N1 and H9N2 live-attenuated influenza vaccine (LAIV), the HA and NA genes from a virulent mouse-adapted avian H5N2 (A/WB/Korea/ma81/06) virus and a recently isolated chicken H9N2 (A/CK/Korea/116/06) virus, respectively, were introduced into the A/Puerto Rico/8/34 backbone expressing truncated NS1 proteins (NS1-73, NS1-86, NS1-101, NS1-122) but still possessing a full-length NS gene. Two H5N2/NS1-LAIV viruses (H5N2/NS1-86 and H5N2/NS1-101) were highly attenuated compared with the full-length and remaining H5N2/NS-LAIV viruses in a mouse model. Furthermore, viruses containing NS1 modifications were found to induce more IFN-β activation than viruses with full-length NS1 proteins and were correspondingly attenuated in mice. Intranasal vaccination with a single dose (10(4.0) PFU/ml) of these viruses completely protected mice from a lethal challenge with the homologous A/WB/Korea/ma81/06 (H5N2), heterologous highly pathogenic A/EM/Korea/W149/06 (H5N1), and heterosubtypic highly virulent mouse-adapted H9N2 viruses. This study clearly demonstrates that the modified H5N2/NS1-LAIV viruses attenuated through the introduction of mutations in the NS1 coding region display characteristics that are desirable for live attenuated vaccines and hold potential as vaccine candidates for mammalian hosts. PMID:25959557

  5. Development of prophylactic recombinant HPV58-attenuated Shigeila live vector vaccine and evaluation of its protective efficacy and immunogenicity in the guinea pig keratoconjunctivitis model

    Institute of Scientific and Technical Information of China (English)

    Wensheng Li; Hongli Liu; Xiaofeng Yang; Jin Zheng; Yili Wang; Lusheng Si

    2009-01-01

    To develop a prophylactic recombinant HPV58L1-attenuated Shigella live vector vaccine and evaluate its protective efficacy and immunogenicity in the guinea pig keratoconjunctivitis model, the HPV58L1 gene was cloned into vector pUCmt, and then subcloned into the suicide vector pCVD442. The recombinant plasmid pCVD442-HPV58L1 was introduced into attenuated Shigella (sf301:△virG) with the helper plasmid PRK2013 by filter mating. The positive colonies were harvested and confirmed by polymerase chain reaction. The expression of the HPV58L1 protein with a molecu-lar weight of 60 kDa was confirmed by western blot. The ability of the interested protein to self-assemble into virus-like particles was identified by transmission electron microscope, and murine erythrocyte hemagglu-tination assay. The guinea pig keratoconjunctivitis model was used to evaluate the protective efficacy and immunogenicity of the vaccine. Animal experiments showed that there was no keratoconjunctivitis occurred in the immunized group (HPV58-attenuated Shigella), and the serum levels of anti-HPV58L1-IgG and -IgA were obviously increased (P0.05). Enzyme-linked immunosorbent spot assay showed that HPV58L1-specific IgA-antibody-secreting cells (ASC) and IgG-ASC of spleen and lymph nodes were also obviously increased (P<0.01). In this study, a recombi-nant HPV58L1-attenuated Shigella live vector vaccine was successfully constructed, and it could induce strong humoral immune responses in the immunized animals, and induce protective antibody production.

  6. Novel Vaccine against Venezuelan Equine Encephalitis Combines Advantages of DNA Immunization and a Live Attenuated Vaccine

    OpenAIRE

    Tretyakova, Irina; Lukashevich, Igor S; Glass, Pamela; Wang, Eryu; Weaver, Scott; Pushko, Peter

    2012-01-01

    DNA vaccines combine remarkable genetic and chemical stability with proven safety and efficacy in animal models, while remaining less immunogenic in humans. In contrast, live-attenuated vaccines have the advantage of inducing rapid, robust, long-term immunity after a single-dose vaccination. Here we describe novel iDNA vaccine technology that is based on an infectious DNA platform and combines advantages of DNA and live attenuated vaccines. We applied this technology for vaccination against i...

  7. A replication-deficient rabies virus vaccine expressing Ebola virus glycoprotein is highly attenuated for neurovirulence

    OpenAIRE

    Papaneri, Amy B.; Wirblich, Christoph; Cann, Jennifer A.; Cooper, Kurt; Peter B. Jahrling; Schnell, Matthias J.; Blaney, Joseph E.

    2012-01-01

    We are developing inactivated and live-attenuated rabies virus (RABV) vaccines expressing Ebola virus (EBOV) glycoprotein for use in humans and endangered wildlife, respectively. Here, we further characterize the pathogenesis of the live-attenuated RABV/EBOV vaccine candidates in mice in an effort to define their growth properties and potential for safety. RABV vaccines expressing GP (RV-GP) or a replication-deficient derivative with a deletion of the RABV G gene (RVΔG-GP) are both avirulent ...

  8. Characterization of a multicomponent live, attenuated Shigella flexneri vaccine.

    Science.gov (United States)

    DeLaine, BreOnna C; Wu, Tao; Grassel, Christen L; Shimanovich, Avital; Pasetti, Marcela F; Levine, Myron M; Barry, Eileen M

    2016-07-01

    Shigella flexneri is a leading cause of diarrheal disease in children under five in developing countries. There is currently no licensed vaccine and broad spectrum protection requires coverage of multiple serotypes. The live attenuated vaccines CVD 1213 and CVD 1215 were derived from two prominent S. flexneri serotypes: S. flexneri 3a and S. flexneri 6. To provide broad-spectrum immunity, they could be combined with CVD 1208S, a S. flexneri 2a strain that demonstrated promising results in phase I and II clinical trials. Each strain contains a mutation in the guaBA operon. These vaccine candidates were tested in vitro and in vivo and were found to be auxotrophic for guanine and defective in intracellular replication, but capable of inducing cytokine production from both epithelial cells and macrophages. Both strains were attenuated for virulence in the guinea pig Serény test and induced robust serotype-specific antibody responses following immunization. Each strain induced homologous serotype protection against challenge and a mixed inoculum of the three S. flexneri vaccines conferred protection against all three virulent wild-type strains. These data support the use of CVD 1213, CVD 1215 and CVD 1208S in a multivalent vaccine to confer broad protection against disease caused by Shigella flexneri. PMID:27106253

  9. Evaluation of live attenuated measles vaccines prepared in human diploid cells for reimmunization.

    OpenAIRE

    Mirchamsy, H.; Shafyi, A; Nazari, P.; Ashtiani, M. P.; Sassani, A.

    1988-01-01

    Two live attenuated measles vaccines developed in baby calf kidney cells, a similar vaccine produced in chick embryo chorioallantoic cells and five vaccines prepared from human diploid cells (HDC) have been studied by subcutaneous injection in groups of susceptible and immune children in three field trials. The results indicated that the vaccine developed in chick embryo cells which caused mild clinical reactions, had induced a lower seroprotection rate in susceptible children and only a low ...

  10. The efficacy of an inhibin DNA vaccine delivered by attenuated Salmonella choleraesuis on follicular development and ovulation responses in crossbred buffaloes.

    Science.gov (United States)

    Liu, Qing; Han, Li; Rehman, Zia Ur; Dan, Xingang; Liu, Xiaoran; Bhattarai, Dinesh; Yang, Liguo

    2016-09-01

    The aim of this study was to evaluate the efficacy of an inhibin DNA vaccine delivered by attenuated Salmonella choleraesuis on follicular development and ovulation responses in crossbred buffaloes. A total of 158 crossbred buffaloes divided into four groups and were intramuscularly injected with 1×10(10) (T1, n=41), 1×10(9) (T2, n=37), 1×10(8) (T3, n=37) or 0 (C, n=43) CFU/ml bacteria delivered inhibin vaccine in 10ml PBS on day 0 and 14, respectively. All animals were administered with 1000 IU PMSG on day 28, 0.5mg PGF2α on day 30 and 200μg GnRH on day 32. The results showed buffaloes immunized with the bacteria delivered inhibin vaccine had significantly higher titers of anti-inhibin IgG antibody than control group (Pvaccine, coupled with the estrus synchronization protocol, could be used as an alternative approach to improve fertility in crossbred buffaloes. PMID:27449408

  11. T- and B-Cell-Mediated Protection Induced by Novel, Live Attenuated Pertussis Vaccine in Mice. Cross Protection against Parapertussis

    OpenAIRE

    Pascal Feunou Feunou; Julie Bertout; Camille Locht

    2010-01-01

    BACKGROUND: Despite the extensive use of efficacious vaccines, pertussis still ranks among the major causes of childhood mortality worldwide. Two types of pertussis vaccines are currently available, whole-cell, and the more recent acellular vaccines. Because of reduced reactogenicity and comparable efficacy acellular vaccines progressively replace whole-cell vaccines. However, both types require repeated administrations for optimal efficacy. We have recently developed a live attenuated vaccin...

  12. Clinical vaccine development

    OpenAIRE

    Han, Seunghoon

    2015-01-01

    Vaccination is regarded as one of the biggest triumphs in the history of medicine. We are living in the most successful period of vaccine development. The accumulation of multidisciplinary knowledge and the investment of massive funding have enabled the development of vaccines against many infectious diseases as well as other diseases including malignant tumors. The paradigm of clinical vaccine evaluation and licensure has also been modernized based on scientific improvements and historical e...

  13. Development of a recombinant epsilon toxoid vaccine against enterotoxemia and its use as a combination vaccine with live attenuated sheep pox virus against enterotoxemia and sheep pox.

    Science.gov (United States)

    Chandran, Dev; Naidu, Sureddi Satyam; Sugumar, Parthasarathy; Rani, Gudavalli Sudha; Vijayan, Shahana Pallichera; Mathur, Deepika; Garg, Lalit C; Srinivasan, Villuppanoor Alwar

    2010-06-01

    Sheep pox and enterotoxemia are important diseases of sheep, and these diseases cause severe economic losses to sheep farmers. The present study was undertaken to evaluate the potential of formaldehyde-inactivated recombinant epsilon toxin as a vaccine candidate. The potency of the recombinant epsilon toxoid with aluminum hydroxide as an adjuvant in sheep was determined. Vaccinated sheep were protected against enterotoxemia, with potency values of >5 IU being protective. Further, the use of this construct in a combination vaccine against sheep pox resulted in the sheep being protected against both sheep pox and enterotoxemia. PMID:20427629

  14. Development of a Recombinant Epsilon Toxoid Vaccine against Enterotoxemia and Its Use as a Combination Vaccine with Live Attenuated Sheep Pox Virus against Enterotoxemia and Sheep Pox▿

    Science.gov (United States)

    Chandran, Dev; Naidu, Sureddi Satyam; Sugumar, Parthasarathy; Rani, Gudavalli Sudha; Vijayan, Shahana Pallichera; Mathur, Deepika; Garg, Lalit C.; Srinivasan, Villuppanoor Alwar

    2010-01-01

    Sheep pox and enterotoxemia are important diseases of sheep, and these diseases cause severe economic losses to sheep farmers. The present study was undertaken to evaluate the potential of formaldehyde-inactivated recombinant epsilon toxin as a vaccine candidate. The potency of the recombinant epsilon toxoid with aluminum hydroxide as an adjuvant in sheep was determined. Vaccinated sheep were protected against enterotoxemia, with potency values of >5 IU being protective. Further, the use of this construct in a combination vaccine against sheep pox resulted in the sheep being protected against both sheep pox and enterotoxemia. PMID:20427629

  15. Development of a Recombinant Epsilon Toxoid Vaccine against Enterotoxemia and Its Use as a Combination Vaccine with Live Attenuated Sheep Pox Virus against Enterotoxemia and Sheep Pox▿

    OpenAIRE

    Chandran, Dev; Naidu, Sureddi Satyam; Sugumar, Parthasarathy; Rani, Gudavalli Sudha; Vijayan, Shahana Pallichera; Mathur, Deepika; Garg, Lalit C; Srinivasan, Villuppanoor Alwar

    2010-01-01

    Sheep pox and enterotoxemia are important diseases of sheep, and these diseases cause severe economic losses to sheep farmers. The present study was undertaken to evaluate the potential of formaldehyde-inactivated recombinant epsilon toxin as a vaccine candidate. The potency of the recombinant epsilon toxoid with aluminum hydroxide as an adjuvant in sheep was determined. Vaccinated sheep were protected against enterotoxemia, with potency values of >5 IU being protective. Further, the use of t...

  16. A breakthrough in the development of the novel live-attenuated vaccines for rabies%新型狂犬病减毒活疫苗研究的重大突破

    Institute of Scientific and Technical Information of China (English)

    解庭波; 唐芳; 严家新

    2010-01-01

    There is a great breakthrough in the development of rabies vaccine. These novel live-attenuated vaccines for rabies are very effective and safe, and may even be used as the early treatment at the onset of rabies. These novel vaccines have been recognized as an important milestone since the rabies vaccine was first developed more than 100 years ago. In this review, the breakthrough in the development of rabies vaccine , some related factors determining the pathogenicity and immunogenicity of rabies virus and the advances in the development of these novel live-attenuated rabies vaccines are summarized.%最近狂犬病疫苗研究取得重大突破.新型狂犬病减毒活疫苗效力更高而且高度安全,甚至有可能用于狂犬病发病后的早期治疗.这是狂犬病疫苗诞生一百多年来的一个重要里程碑.此文对狂犬病疫苗研究取得的重大突破、决定狂犬病病毒致病性和免疫原性的相关因素及新型狂犬病减毒活疫苗的主要优点作一综述.

  17. Vaccine development using recombinant DNA technology

    Science.gov (United States)

    Vaccines induce an immune response in the host that subsequently recognizes infectious agents and helps fight off the disease; vaccines must do this without causing the disease. This paper reviews the development of recombinant DNA technologies as a means of providing new ways for attenuating diseas...

  18. Comparison of the nucleotide sequence of wild-type hepatitis - A virus and its attenuated candidate vaccine derivative

    International Nuclear Information System (INIS)

    Development of attenuated mutants for use as vaccines is in progress for other viruses, including influenza, rotavirus, varicella-zoster, cytomegalovirus, and hepatitis-A virus (HAV). Attenuated viruses may be derived from naturally occurring mutants that infect human or nonhuman hosts. Alternatively, attenuated mutants may be generated by passage of wild-type virus in cell culture. Production of attenuated viruses in cell culture is a laborious and empiric process. Despite previous empiric successes, understanding the molecular basis for attenuation of vaccine viruses could facilitate future development and use of live-virus vaccines. Comparison of the complete nucleotide sequences of wild-type (virulent) and vaccine (attenuated) viruses has been reported for polioviruses and yellow fever virus. Here, the authors compare the nucleotide sequence of wild-type HAV HM-175 with that of a candidate vaccine derivative

  19. 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.

  20. Live attenuated vaccines: Historical successes and current challenges

    International Nuclear Information System (INIS)

    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

  1. Immunoglobulins in pigs vaccinated with a subunit E2 and an attenuated c strain vaccine against classical swine fever

    Directory of Open Access Journals (Sweden)

    Terzić Svjetlana

    2009-01-01

    Full Text Available The aim of this study was to detect changes in the concentration of serum immunoglobulins following vaccination against classical swine fever (CSF with an attenuated C strain and a subunit E2 vaccine. Furthermore, the adjuvanticity of an attenuated parapoxvirus ORF virus for the subunit vaccine against CSF was evaluated. Peripheral blood samples were collected before the vaccination and at post-vaccination days 4, 10, 21 and 28. The samples were assessed by a colorimetric method for the detection of total proteins, as well as albumin, IgA and IgM levels and by radial immunodiffusion to record the IgG level. Our findings are in accordance with the normal concentrations of porcine IgG, IgA and IgM. However, a significant increase of some immunoglobulin classes was recorded. The increase of the IgM level in vaccinated pigs confirmed an early development of humoral immunity. Interestingly, the subunit E2 vaccine induced the increase of IgM earlier then did the attenuated C strain. Since the IgG concentration was not significantly increased we assumed that the period of 28 days following vaccination was too short to detect any changes in the IgG level, thus reflecting a late humoral immune response. Although, IgA antibodies are mostly responsible for humoral immunity at the mucosal surfaces, in our experiment the attenuated C strain induced a significantly higher production of this immunoglobulin class in the serum very early (on day 4 following vaccination. This could be ascribed to the affinity of IgA antibodies to neutralize or agglutinate virus particles. Early appearance (4 and 10 days after the vaccination of a significantly higher concentration of IgG and IgM could be induced by the ORF virus strain D1701 applied as an adjuvant.

  2. Antibody response in cattle after vaccination with inactivated and attenuated rabies vaccines

    OpenAIRE

    RODRIGUES da SILVA Andréa de Cássia; Caporale, Graciane Maria Medeiros; GONÇALVES Celso Alberto; TARGUETA Mosar Couteiro; Fabiano COMIN; Carlos Roberto ZANETTI; Kotait, Ivanete

    2000-01-01

    Despite the absence of current official reports showing the number of cattle infected by rabies, it is estimated that nearly 30,000 bovines are lost each year in Brazil. In order to minimize the important economic losses, control of the disease is achieved by eliminating bat colonies and by herd vaccination. In this study, we compare the antibody response in cattle elicited by vaccination with an attenuated ERA vaccine (AEvac) and an inactivated-adjuvanted PV (IPVvac) vaccine. The antibody ti...

  3. Attenuated vaccines can recombine to form virulent field viruses.

    Science.gov (United States)

    Lee, Sang-Won; Markham, Philip F; Coppo, Mauricio J C; Legione, Alistair R; Markham, John F; Noormohammadi, Amir H; Browning, Glenn F; Ficorilli, Nino; Hartley, Carol A; Devlin, Joanne M

    2012-07-13

    Recombination between herpesviruses has been seen in vitro and in vivo under experimental conditions. This has raised safety concerns about using attenuated herpesvirus vaccines in human and veterinary medicine and adds to other known concerns associated with their use, including reversion to virulence and disease arising from recurrent reactivation of lifelong chronic infection. We used high-throughput sequencing to investigate relationships between emergent field strains and vaccine strains of infectious laryngotracheitis virus (ILTV, gallid herpesvirus 1). We show that independent recombination events between distinct attenuated vaccine strains resulted in virulent recombinant viruses that became the dominant strains responsible for widespread disease in Australian commercial poultry flocks. These findings highlight the risks of using multiple different attenuated herpesvirus vaccines, or vectors, in the same populations. PMID:22798607

  4. Multiple vaccinations with UV- attenuated cercariae in pig enhance protective immunity against Schistosoma japonicum infection as compared to single vaccination

    OpenAIRE

    Zhang Donghui; Wu Jingjiao; Gao Yanan; Wu Haiwei; Tian Fang; Lin Dandan; Ji Minjun; McManus Donald P; Driguez Patrick; Wu Guanling

    2011-01-01

    Abstract Background Schistosomiasis japonica is a major public health problem in the endemic areas of China, the Philippines, and Indonesia. To date, a vaccine has not been developed against this disease but immunization with UV-attenuated cercariae can induce a high level of protective immunity in Landrace/Yorkshire/Duroc crossbred pigs. To compare the efficacy of a single vaccination and multiple vaccinations with UV-attenuated Schistosoma japonicum cercariae, two groups of pigs received ei...

  5. Genetically engineered, attenuated whole-cell vaccine approaches for malaria

    OpenAIRE

    Vaughan, Ashley M.; Wang, Ruobing; Kappe, Stefan H.I.

    2010-01-01

    Malaria remains one of the most significant infectious diseases affecting human populations in developing countries. The quest for an efficacious malaria vaccine has been ongoing for nearly a century with limited success. The identification of malaria parasite antigens focused efforts on the development of subunit vaccines but has so far yielded only one partially efficacious vaccine candidate, RTS/S. The lack of high vaccine efficacy observed to date with subunit vaccine candidates raises do...

  6. Reactogenicity to a Live Attenuated Varicella Vaccine in Canadian Children

    OpenAIRE

    Diaz-Mitoma, Francisco; Halperin, Scott A.; Scheifele, David

    2000-01-01

    OBJECTIVE: To assess the reactogenicity and safety of a thermostable, high titre, varicella vaccine in healthy infants and children.DESIGN: Open study of 505 children monitored for 42 days after vaccination.SETTING: Three urban Canadian centres (Halifax, Ottawa and Vancouver).PARTICIPANTS: 505 healthy children one to 12 years of age were enrolled and 504 completed the study. All were susceptible to varicella by history.INTERVENTIONS: All participants received one dose of live attenuated varic...

  7. Single-dose attenuated Vesiculovax vaccines protect primates against Ebola Makona virus.

    Science.gov (United States)

    Mire, Chad E; Matassov, Demetrius; Geisbert, Joan B; Latham, Theresa E; Agans, Krystle N; Xu, Rong; Ota-Setlik, Ayuko; Egan, Michael A; Fenton, Karla A; Clarke, David K; Eldridge, John H; Geisbert, Thomas W

    2015-04-30

    The family Filoviridae contains three genera, Ebolavirus (EBOV), Marburg virus, and Cuevavirus. Some members of the EBOV genus, including Zaire ebolavirus (ZEBOV), can cause lethal haemorrhagic fever in humans. During 2014 an unprecedented ZEBOV outbreak occurred in West Africa and is still ongoing, resulting in over 10,000 deaths, and causing global concern of uncontrolled disease. To meet this challenge a rapid-acting vaccine is needed. Many vaccine approaches have shown promise in being able to protect nonhuman primates against ZEBOV. In response to the current ZEBOV outbreak several of these vaccines have been fast tracked for human use. However, it is not known whether any of these vaccines can provide protection against the new outbreak Makona strain of ZEBOV. One of these approaches is a first-generation recombinant vesicular stomatitis virus (rVSV)-based vaccine expressing the ZEBOV glycoprotein (GP) (rVSV/ZEBOV). To address safety concerns associated with this vector, we developed two candidate, further-attenuated rVSV/ZEBOV vaccines. Both attenuated vaccines produced an approximately tenfold lower vaccine-associated viraemia compared to the first-generation vaccine and both provided complete, single-dose protection of macaques from lethal challenge with the Makona outbreak strain of ZEBOV. PMID:25853476

  8. Stability of further-attenuated measles vaccines.

    Science.gov (United States)

    Mann, G F; Allison, L M; Lloyd, J S; Tam, P; Zuckerman, A J; Perkins, F T

    1983-01-01

    Accelerated stability tests on lyophilized measles vaccines show two distinct mechanisms of virus inactivation. A rapid initial loss of infectivity occurs only on exposure to temperatures above the ambient temperature. This loss is temperature related and may be attributable to the movement of residual moisture from the virus pellet into the void space of the vial. Subsequent inactivation of virus occurs at all temperatures as a first-order reaction that follows Arrhenius kinetics. Integration of values for these two components allows precise prediction of vaccine stability at any temperature. Analysis of the results obtained for greater than 30 vaccines shows that those which are stable for one week at 37 C have a predicted life of more than one year at 8 C. This simple test is now being applied to the identification of unstable products. The rate of this reaction is closely, if conservatively, matched by a time-temperature color indicator, which may be useful for monitoring vaccine quality. PMID:6879003

  9. Clinical development of Ebola vaccines.

    Science.gov (United States)

    Sridhar, Saranya

    2015-09-01

    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

  10. Vaccines in development against West Nile virus.

    Science.gov (United States)

    Brandler, Samantha; Tangy, Frederic

    2013-10-01

    West Nile encephalitis emerged in 1999 in the United States, then rapidly spread through the North American continent causing severe disease in human and horses. Since then, outbreaks appeared in Europe, and in 2012, the United States experienced a new severe outbreak reporting a total of 5,387 cases of West Nile virus (WNV) disease in humans, including 243 deaths. So far, no human vaccine is available to control new WNV outbreaks and to avoid worldwide spreading. In this review, we discuss the state-of-the-art of West Nile vaccine development and the potential of a novel safe and effective approach based on recombinant live attenuated measles virus (MV) vaccine. MV vaccine is a live attenuated negative-stranded RNA virus proven as one of the safest, most stable and effective human vaccines. We previously described a vector derived from the Schwarz MV vaccine strain that stably expresses antigens from emerging arboviruses, such as dengue, West Nile or chikungunya viruses, and is strongly immunogenic in animal models, even in the presence of MV pre-existing immunity. A single administration of a recombinant MV vaccine expressing the secreted form of WNV envelope glycoprotein elicited protective immunity in mice and non-human primates as early as two weeks after immunization, indicating its potential as a human vaccine. PMID:24084235

  11. Vaccines in Development against West Nile Virus

    Directory of Open Access Journals (Sweden)

    Frederic Tangy

    2013-09-01

    Full Text Available West Nile encephalitis emerged in 1999 in the United States, then rapidly spread through the North American continent causing severe disease in human and horses. Since then, outbreaks appeared in Europe, and in 2012, the United States experienced a new severe outbreak reporting a total of 5,387 cases of West Nile virus (WNV disease in humans, including 243 deaths. So far, no human vaccine is available to control new WNV outbreaks and to avoid worldwide spreading. In this review, we discuss the state-of-the-art of West Nile vaccine development and the potential of a novel safe and effective approach based on recombinant live attenuated measles virus (MV vaccine. MV vaccine is a live attenuated negative-stranded RNA virus proven as one of the safest, most stable and effective human vaccines. We previously described a vector derived from the Schwarz MV vaccine strain that stably expresses antigens from emerging arboviruses, such as dengue, West Nile or chikungunya viruses, and is strongly immunogenic in animal models, even in the presence of MV pre-existing immunity. A single administration of a recombinant MV vaccine expressing the secreted form of WNV envelope glycoprotein elicited protective immunity in mice and non-human primates as early as two weeks after immunization, indicating its potential as a human vaccine.

  12. A replication-deficient rabies virus vaccine expressing Ebola virus glycoprotein is highly attenuated for neurovirulence

    Energy Technology Data Exchange (ETDEWEB)

    Papaneri, Amy B. [Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, MD 21702 (United States); Wirblich, Christoph [Department of Microbiology and Immunology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107 (United States); Cann, Jennifer A.; Cooper, Kurt [Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick MD, 21702 (United States); Jahrling, Peter B. [Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, MD 21702 (United States); Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick MD, 21702 (United States); Schnell, Matthias J., E-mail: matthias.schnell@jefferson.edu [Department of Microbiology and Immunology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107 (United States); Jefferson Vaccine Center, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107 (United States); Blaney, Joseph E., E-mail: jblaney@niaid.nih.gov [Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, MD 21702 (United States)

    2012-12-05

    We are developing inactivated and live-attenuated rabies virus (RABV) vaccines expressing Ebola virus (EBOV) glycoprotein for use in humans and endangered wildlife, respectively. Here, we further characterize the pathogenesis of the live-attenuated RABV/EBOV vaccine candidates in mice in an effort to define their growth properties and potential for safety. RABV vaccines expressing GP (RV-GP) or a replication-deficient derivative with a deletion of the RABV G gene (RV{Delta}G-GP) are both avirulent after intracerebral inoculation of adult mice. Furthermore, RV{Delta}G-GP is completely avirulent upon intracerebral inoculation of suckling mice unlike parental RABV vaccine or RV-GP. Analysis of RV{Delta}G-GP in the brain by quantitative PCR, determination of virus titer, and immunohistochemistry indicated greatly restricted virus replication. In summary, our findings indicate that RV-GP retains the attenuation phenotype of the live-attenuated RABV vaccine, and RV{Delta}G-GP would appear to be an even safer alternative for use in wildlife or consideration for human use.

  13. A replication-deficient rabies virus vaccine expressing Ebola virus glycoprotein is highly attenuated for neurovirulence

    International Nuclear Information System (INIS)

    We are developing inactivated and live-attenuated rabies virus (RABV) vaccines expressing Ebola virus (EBOV) glycoprotein for use in humans and endangered wildlife, respectively. Here, we further characterize the pathogenesis of the live-attenuated RABV/EBOV vaccine candidates in mice in an effort to define their growth properties and potential for safety. RABV vaccines expressing GP (RV-GP) or a replication-deficient derivative with a deletion of the RABV G gene (RVΔG-GP) are both avirulent after intracerebral inoculation of adult mice. Furthermore, RVΔG-GP is completely avirulent upon intracerebral inoculation of suckling mice unlike parental RABV vaccine or RV-GP. Analysis of RVΔG-GP in the brain by quantitative PCR, determination of virus titer, and immunohistochemistry indicated greatly restricted virus replication. In summary, our findings indicate that RV-GP retains the attenuation phenotype of the live-attenuated RABV vaccine, and RVΔG-GP would appear to be an even safer alternative for use in wildlife or consideration for human use.

  14. Rabies virus pathogenesis in relationship to intervention with inactivated and attenuated rabies vaccines.

    Science.gov (United States)

    Franka, Richard; Wu, Xianfu; Jackson, Felix R; Velasco-Villa, Andres; Palmer, Dustyn P; Henderson, Heather; Hayat, Wajid; Green, Douglas B; Blanton, Jesse D; Greenberg, Lauren; Rupprecht, Charles E

    2009-11-27

    Despite progress in vaccine development in the past century the mechanisms behind immune responses elicited by rabies biologics or via natural infection remain largely unknown. In this study, we compared protection elicited by standard, early, or delayed prophylaxis with a reduced number of vaccine doses using inactivated and live-attenuated vaccines. Two-month-old Syrian hamsters, 4-week-old ICR mice or adult rhesus macaques were inoculated with canine rabies virus variants. Thereafter, prophylaxis was initiated 6h, 1, 2, 3, 4, 5, 6 or 7 days post-exposure (p.e.). One or several doses of inactivated (HDCV), or reverse genetically attenuated (live), or gamma-irradiated (inactivated)-ERAG333 vaccines were administered intramuscularly. The dynamics of virus spread were measured over time in the rodent models. Rabies virus reached the spinal cord at day 4 and brain at day 6 p.e. All hamsters succumbed in groups in which live ERAG333 was delayed until days 5 and 6 p.e. However, 78%, 44%, 56% and 22% of hamsters survived when one dose of live ERAG333 was administered 6h, 1, 2, 3, and 4 days p.e., respectively. Similarly, 67% survived when inactivated ERAG333 was administered at 24h p.e. All hamsters succumbed when standard prophylaxis (the Essen regimen) was delayed until days 3-6, but 67% and 33% of hamsters survived when PEP began 1 or 2 days p.e., respectively. Macaques were protected by one dose of attenuated ERAG333 at 24h p.e. The highly attenuated (live) and inactivated ERAG333 vaccines elicited potent protective immune responses, even when prophylaxis initiation was delayed. When 2-5 doses of commercial vaccine and HRIG were administered according to the Essen scheme, 89-100% of the animals survived. Reduced vaccine schedules provided efficacious intervention, regardless of the total number of vaccine doses administered. PMID:19925945

  15. Attenuated Bordetella pertussis Vaccine Protects against Respiratory Syncytial Virus Disease via an IL-17-Dependent Mechanism

    OpenAIRE

    Sawant, Devika; Schnoeller, Corinna; Roux, Xavier; Openshaw, Peter J.; Olszewska, Wieslawa; Locht, Camille; Raze, Dominique

    2014-01-01

    Rationale: We attenuated virulent Bordetella pertussis by genetically eliminating or detoxifying three major toxins. This strain, named BPZE1, is being developed as a possible live nasal vaccine for the prevention of whooping cough. It is immunogenic and safe when given intranasally in adult volunteers.

  16. 78 FR 43219 - Prospective Grant of Exclusive License: Live Attenuated Dengue Tetravalent Vaccine Containing a...

    Science.gov (United States)

    2013-07-19

    ... means for prevention of dengue infection and dengue hemorrhagic fever (DHF) by immunization with... Dengue Tetravalent Vaccine Containing a Common 30 Nucleotide Deletion in the 3'-UTR of Dengue Types 1, 2... et al., ``Development of Mutations Useful for Attenuating Dengue Viruses and Chimeric Dengue...

  17. Schistosoma japonicum: An ultraviolet-attenuated cercarial vaccine applicable in the field for water buffaloes

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Y.E.; Jiang, C.F.; Han, J.J.; Li, Y.L.; Ruppel, A. (Tongii Medical Univ., Wuhan, Hubei Province (China))

    1990-07-01

    Water buffaloes were vaccinated three times with 10,000 Schistosoma japonicum cercariae irradiated with ultraviolet (uv) light at a dose of 400 microW x min/cm2. The irradiation was performed with cheap, simple, and portable equipment in a rural area of Hubei Province (People's Republic of China). A challenge infection of 1000 untreated cercariae was given to six vaccinated and six naive control buffaloes, while two vaccinated animals were not challenged. The experiment was terminated 6 weeks after the challenge. Control animals had lost body weight and harbored a mean of 110 worms and 37 eggs per gram of liver. The vaccinated animals gained weight after the challenge and developed 89% resistance to infection with S. japonicum. Since schistosomiasis japonica is nowadays transmitted in China predominantly by domestic livestock, a uv-attenuated cercarial vaccine for bovines may contribute to the control of this disease.

  18. Schistosoma japonicum: An ultraviolet-attenuated cercarial vaccine applicable in the field for water buffaloes

    International Nuclear Information System (INIS)

    Water buffaloes were vaccinated three times with 10,000 Schistosoma japonicum cercariae irradiated with ultraviolet (uv) light at a dose of 400 microW x min/cm2. The irradiation was performed with cheap, simple, and portable equipment in a rural area of Hubei Province (People's Republic of China). A challenge infection of 1000 untreated cercariae was given to six vaccinated and six naive control buffaloes, while two vaccinated animals were not challenged. The experiment was terminated 6 weeks after the challenge. Control animals had lost body weight and harbored a mean of 110 worms and 37 eggs per gram of liver. The vaccinated animals gained weight after the challenge and developed 89% resistance to infection with S. japonicum. Since schistosomiasis japonica is nowadays transmitted in China predominantly by domestic livestock, a uv-attenuated cercarial vaccine for bovines may contribute to the control of this disease

  19. Genetic characterisation of attenuated SAD rabies virus strains used for oral vaccination of wildlife.

    Science.gov (United States)

    Geue, Lutz; Schares, Susann; Schnick, Christina; Kliemt, Jeannette; Beckert, Aline; Freuling, Conrad; Conraths, Franz J; Hoffmann, Bernd; Zanoni, Reto; Marston, Denise; McElhinney, Lorraine; Johnson, Nicholas; Fooks, Anthony R; Tordo, Noel; Müller, Thomas

    2008-06-19

    The elimination of rabies from the red fox (Vulpes vulpes) in Western Europe has been achieved by the oral rabies vaccination (ORV) of wildlife with a range of attenuated rabies virus strains. With the exception of the vaccinia rabies glycoprotein recombinant vaccine (VRG), all strains were originally derived from a common ancestor; the Street Alabama Dufferin (SAD) field strain. However, after more than 30 years of ORV it is still not possible to distinguish these vaccine strains and there is little information on the genetic basis for their attenuation. We therefore sequenced and compared the full-length genome of five commercially available SAD vaccine viruses (SAD B19, SAD P5/88, SAG2, SAD VA1 and SAD Bern) and four other SAD strains (the original SAD Bern, SAD VA1, ERA and SAD 1-3670 Wistar). Nucleotide sequencing allowed identifying each vaccine strain unambiguously. Phylogenetic analysis revealed that the majority of the currently used commercial attenuated rabies virus vaccines appear to be derived from SAD B19 rather than from SAD Bern. One commercially available vaccine virus did not contain the SAD strain mentioned in the product information of the producer. Two SAD vaccine strains appeared to consist of mixed genomic sequences. Furthermore, in-del events targeting A-rich sequences (in positive strand) within the 3' non-coding regions of M and G genes were observed in SAD-derivates developed in Europe. Our data also supports the idea of a possible recombination that had occurred during the derivation of the European branch of SAD viruses. If confirmed, this recombination event would be the first one reported among RABV vaccine strains. PMID:18485548

  20. 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

  1. Development of Streptococcus pneumoniae Vaccines Using Live Vectors

    Directory of Open Access Journals (Sweden)

    Shifeng Wang

    2014-01-01

    Full Text Available Streptococcus pneumoniae still causes severe morbidity and mortality worldwide, especially in young children and the elderly. Much effort has been dedicated to developing protein-based universal vaccines to conquer the current shortcomings of capsular vaccines and capsular conjugate vaccines, such as serotype replacement, limited coverage and high costs. A recombinant live vector vaccine delivering protective antigens is a promising way to achieve this goal. In this review, we discuss the researches using live recombinant vaccines, mainly live attenuated Salmonella and lactic acid bacteria, to deliver pneumococcal antigens. We also discuss both the limitations and the future of these vaccines.

  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. Immunogenicity and Protective Efficacy of a Live Attenuated H5N1 Vaccine in Nonhuman Primates

    Science.gov (United States)

    Fan, Shufang; Gao, Yuwei; Shinya, Kyoko; Li, Chris Kafai; Li, Yanbing; Shi, Jianzhong; Jiang, Yongping; Suo, Yongbing; Tong, Tiegang; Zhong, Gongxun; Song, Jiasheng; Zhang, Ying; Tian, Guobin; Guan, Yuntao; Xu, Xiao-Ning; Bu, Zhigao; Kawaoka, Yoshihiro; Chen, Hualan

    2009-01-01

    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. PMID:19412338

  4. Macrophages as effector cells of protective immunity in murine schistosomiasis: macrophage activation in mice vaccinated with radiation-attenuated cercariae.

    OpenAIRE

    James, S L; Natovitz, P C; Farrar, W L; Leonard, E.J.

    1984-01-01

    Cell-mediated immune responses contributing to macrophage activation were compared in mice that demonstrated partial resistance to challenge Schistosoma mansoni infection as a result of vaccination with radiation-attenuated cercariae or of ongoing low-grade primary infection. Vaccinated mice developed significant delayed hypersensitivity reactions to soluble schistosome antigens in vivo. Splenocytes from vaccinated animals responded to in vitro culture with various specific antigens (soluble ...

  5. 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. PMID:27468028

  6. Developments in rabies vaccines.

    Science.gov (United States)

    Hicks, D J; Fooks, A R; Johnson, N

    2012-09-01

    The development of vaccines that prevent rabies has a long and distinguished history, with the earliest preceding modern understanding of viruses and the mechanisms of immune protection against disease. The correct application of inactivated tissue culture-derived vaccines is highly effective at preventing the development of rabies, and very few failures are recorded. Furthermore, oral and parenteral vaccination is possible for wildlife, companion animals and livestock, again using inactivated tissue culture-derived virus. However, rabies remains endemic in many regions of the world and causes thousands of human deaths annually. There also remain no means of prophylaxis for rabies once the virus enters the central nervous system (CNS). One reason for this is the poor immune response within the CNS to infection with rabies virus (RABV). New approaches to vaccination using modified rabies viruses that express components of the innate immune system are being applied to this problem. Preliminary reports suggest that direct inoculation of such viruses could trigger an effective anti-viral response and prevent a fatal outcome from RABV infection. PMID:22861358

  7. Low dose vaccination with attenuated Francisella tularensis strain SchuS4 mutants protects against tularemia independent of the route of vaccination.

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    Dedeke Rockx-Brouwer

    Full Text Available Tularemia, caused by the gram-negative bacterium Francisella tularensis, is a severe, sometimes fatal disease. Interest in tularemia has increased over the last decade due to its history as a biological weapon. In particular, development of novel vaccines directed at protecting against pneumonic tularemia has been an important goal. Previous work has demonstrated that, when delivered at very high inoculums, administration of live, highly attenuated strains of virulent F. tularensis can protect against tularemia. However, lower vaccinating inoculums did not offer similar immunity. One concern of using live vaccines is that the host may develop mild tularemia in response to infection and use of high inoculums may contribute to this issue. Thus, generation of a live vaccine that can efficiently protect against tularemia when delivered in low numbers, e.g. <100 organisms, may address this concern. Herein we describe the ability of three defined, attenuated mutants of F. tularensis SchuS4, deleted for FTT0369c, FTT1676, or FTT0369c and FTT1676, respectively, to engender protective immunity against tularemia when delivered at concentrations of approximately 50 or fewer bacteria. Attenuated strains for use as vaccines were selected by their inability to efficiently replicate in macrophages in vitro and impaired replication and dissemination in vivo. Although all strains were defective for replication in vitro within macrophages, protective efficacy of each attenuated mutant was correlated with their ability to modestly replicate and disseminate in the host. Finally, we demonstrate the parenteral vaccination with these strains offered superior protection against pneumonic tularemia than intranasal vaccination. Together our data provides proof of principle that low dose attenuated vaccines may be a viable goal in development of novel vaccines directed against tularemia.

  8. Review: New Vaccine Against Tuberculosis: Current Developments and Future Challenges

    Science.gov (United States)

    Liu, Jun

    2009-04-01

    Tuberculosis (TB) continues to be a global health threat. BCG was developed as an attenuated live vaccine for tuberculosis control nearly a century ago. Despite being the most widely used vaccine in human history, BCG is not an ideal vaccine and has two major limitations: its poor efficacy against adult pulmonary TB and its disconcerting safety in immunocompromised individuals. A safer and more effective TB vaccine is urgently needed. This review article discusses current strategies to develop the next generation of TB vaccines to replace BCG. While some progresses have been made in the past decade, significant challenges lie ahead.

  9. Recombinant vaccines and the development of new vaccine strategies

    International Nuclear Information System (INIS)

    Vaccines were initially developed on an empirical basis, relying mostly on attenuation or inactivation of pathogens. Advances in immunology, molecular biology, biochemistry, genomics, and proteomics have added new perspectives to the vaccinology field. The use of recombinant proteins allows the targeting of immune responses focused against few protective antigens. There are a variety of expression systems with different advantages, allowing the production of large quantities of proteins depending on the required characteristics. Live recombinant bacteria or viral vectors effectively stimulate the immune system as in natural infections and have intrinsic adjuvant properties. DNA vaccines, which consist of non-replicating plasmids, can induce strong long-term cellular immune responses. Prime-boost strategies combine different antigen delivery systems to broaden the immune response. In general, all of these strategies have shown advantages and disadvantages, and their use will depend on the knowledge of the mechanisms of infection of the target pathogen and of the immune response required for protection. In this review, we discuss some of the major breakthroughs that have been achieved using recombinant vaccine technologies, as well as new approaches and strategies for vaccine development, including potential shortcomings and risks

  10. Recombinant vaccines and the development of new vaccine strategies

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, I.P.; Leite, L.C.C. [Centro de Biotecnologia, Instituto Butantan, São Paulo, SP (Brazil)

    2012-09-07

    Vaccines were initially developed on an empirical basis, relying mostly on attenuation or inactivation of pathogens. Advances in immunology, molecular biology, biochemistry, genomics, and proteomics have added new perspectives to the vaccinology field. The use of recombinant proteins allows the targeting of immune responses focused against few protective antigens. There are a variety of expression systems with different advantages, allowing the production of large quantities of proteins depending on the required characteristics. Live recombinant bacteria or viral vectors effectively stimulate the immune system as in natural infections and have intrinsic adjuvant properties. DNA vaccines, which consist of non-replicating plasmids, can induce strong long-term cellular immune responses. Prime-boost strategies combine different antigen delivery systems to broaden the immune response. In general, all of these strategies have shown advantages and disadvantages, and their use will depend on the knowledge of the mechanisms of infection of the target pathogen and of the immune response required for protection. In this review, we discuss some of the major breakthroughs that have been achieved using recombinant vaccine technologies, as well as new approaches and strategies for vaccine development, including potential shortcomings and risks.

  11. 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.

  12. Antibody response in cattle after vaccination with inactivated and attenuated rabies vaccines

    Directory of Open Access Journals (Sweden)

    RODRIGUES da SILVA Andréa de Cássia

    2000-01-01

    Full Text Available Despite the absence of current official reports showing the number of cattle infected by rabies, it is estimated that nearly 30,000 bovines are lost each year in Brazil. In order to minimize the important economic losses, control of the disease is achieved by eliminating bat colonies and by herd vaccination. In this study, we compare the antibody response in cattle elicited by vaccination with an attenuated ERA vaccine (AEvac and an inactivated-adjuvanted PV (IPVvac vaccine. The antibody titers were appraised by cell-culture neutralization test and ELISA, and the percentage of seropositivity was ascertained for a period of 180 days. IPVvac elicited complete seropositivity rates from day 30 to day 150, and even on day 180, 87% of the sera showed virus-neutralizing antibody titers (VNA higher than 0.5IU/ml. There were no significant differences between the VNA titers and seropositivity rates obtained with IPVvac in the two methods tested. AEvac, however, elicited significantly lower titers than those observed in the group receiving inactivated vaccine. In addition, the profiles of antirabies IgG antibodies, evaluated by ELISA, and VNA, appraised by cell-culture neutralization test, were slightly different, when both vaccines were compared.

  13. Antibody response in cattle after vaccination with inactivated and attenuated rabies vaccines.

    Science.gov (United States)

    Rodrigues da Silva, A C; Caporale, G M; Gonçalves, C A; Targueta, M C; Comin, F; Zanetti, C R; Kotait, I

    2000-01-01

    Despite the absence of current official reports showing the number of cattle infected by rabies, it is estimated that nearly 30,000 bovines are lost each year in Brazil. In order to minimize the important economic losses, control of the disease is achieved by eliminating bat colonies and by herd vaccination. In this study, we compare the antibody response in cattle elicited by vaccination with an attenuated ERA vaccine (AEvac) and an inactivated-adjuvanted PV (IPVvac) vaccine. The antibody titers were appraised by cell-culture neutralization test and ELISA, and the percentage of seropositivity was ascertained for a period of 180 days. IPVvac elicited complete seropositivity rates from day 30 to day 150, and even on day 180, 87% of the sera showed virus-neutralizing antibody titers (VNA) higher than 0.5IU/ml. There were no significant differences between the VNA titers and seropositivity rates obtained with IPVvac in the two methods tested. AEvac, however, elicited significantly lower titers than those observed in the group receiving inactivated vaccine. In addition, the profiles of antirabies IgG antibodies, evaluated by ELISA, and VNA, appraised by cell-culture neutralization test, were slightly different, when both vaccines were compared. PMID:10810324

  14. 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

  15. [Diarrhea and vaccines: current developments].

    Science.gov (United States)

    Landry, P

    2006-05-10

    Diarrhoea is a main concern for travellers, populations of developing countries and children. Causative pathogens are numerous. An efficient vaccine against cholera is available, also offering a 50% cross-protection against E. Coli enterotoxin (ETEC), however its efficacy is only 23% against all-causes traveller's diarrhoea. Rotavirus can be responsible for severe diarrhoea in infants but rarely causes traveller's diarrhoea. Two new vaccines being under development appear effective and well-tolerated but too expensive for developing countries which most need them. To date, the live oral Ty21a vaccine remains frequently prescribed in Switzerland, with limited indications and suboptimal efficacy. A new oral vaccine is under development. PMID:16767878

  16. [Approaches and problems in vaccine development against leishmaniasis].

    Science.gov (United States)

    Allahverdiyev, Adil; Bağirova, Melahat; Cakir Koç, Rabia; Oztel, Olga Nehir; Elçıçek, Serhat; Ateş, Sezen Canım; Karaca, Tuğçe Deniz

    2010-01-01

    Leishmaniasis is a major public health problem of the world and Turkey. Recently there has been increasing interest in vaccine studies among strategies for control of leishmaniasis. Recently the increase of interest in vaccine studies among leishmaniasis control strategies makes the subject more up to date. So the aim of this review is to present information about recent vaccine studies, problems and new strategies for vaccine development studies. There are 3 generations of vaccine against leishmaniasis. First-generation vaccines are killed or live attenuated parasites; second-generation vaccines are recombinant or native antigens and live genetically modified parasites (knock out and suicidal cassettes), third generation vaccines are DNA vaccines. Also vector salivary proteins, dendritic cells and non-pathogenic L. tarentolae have been used as vaccine candidates. However there is still no effective vaccine against leishmaniasis. Since polymer conjugates considerably increase immunogenicity, polymer based vaccine studies have gained importance in recent years. However, there has not been such a study for an antileishmanial vaccine yet. LPG, surface antigen of Leishmania promastigotes, and polymer conjugates may be promising in antileishmanial vaccine studies so we are carrying out a TUBITAK Project on this subject which has been given the number, 1085170SBAG-4007. PMID:20597059

  17. Vaccination against canine distemper virus infection in infant ferrets with and without maternal antibody protection, using recombinant attenuated poxvirus vaccines.

    Science.gov (United States)

    Welter, J; Taylor, J; Tartaglia, J; Paoletti, E; Stephensen, C B

    2000-07-01

    Canine distemper virus (CDV) infection of ferrets is clinically and immunologically similar to measles, making this a useful model for the human disease. The model was used to determine if parenteral or mucosal immunization of infant ferrets at 3 and 6 weeks of age with attenuated vaccinia virus (NYVAC) or canarypox virus (ALVAC) vaccine strains expressing the CDV hemagglutinin (H) and fusion (F) protein genes (NYVAC-HF and ALVAC-HF) would induce serum neutralizing antibody and protect against challenge infection at 12 weeks of age. Ferrets without maternal antibody that were vaccinated parenterally with NYVAC-HF (n = 5) or ALVAC-HF (n = 4) developed significant neutralizing titers (log(10) inverse mean titer +/- standard deviation of 2.30 +/- 0.12 and 2.20 +/- 0.34, respectively) by the day of challenge, and all survived with no clinical or virologic evidence of infection. Ferrets without maternal antibody that were vaccinated intranasally (i.n.) developed lower neutralizing titers, with NYVAC-HF producing higher titers at challenge (1.11 +/- 0.57 versus 0.40 +/- 0.37, P = 0.02) and a better survival rate (6/7 versus 0/5, P = 0.008) than ALVAC-HF. Ferrets with maternal antibody that were vaccinated parenterally with NYVAC-HF (n = 7) and ALVAC-HF (n = 7) developed significantly higher antibody titers (1.64 +/- 0. 54 and 1.28 +/- 0.40, respectively) than did ferrets immunized with an attenuated CDV vaccine (0.46 +/- 0.59; n = 7) or the recombinant vectors expressing rabies glycoprotein (RG) (0.19 +/- 0.32; n = 8, P = 7 x 10(-6)). The NYVAC vaccine also protected against weight loss, and both the NYVAC and attenuated CDV vaccines protected against the development of some clinical signs of infection, although survival in each of the three vaccine groups was low (one of seven) and not significantly different from the RG controls (none of eight). Combined i.n.-parenteral immunization of ferrets with maternal antibody using NYVAC-HF (n = 9) produced higher titers (1

  18. An update on safety studies on the attenuated "RIEMSER Schweinepestoralvakzine" for vaccination of wild boar against classical swine fever.

    Science.gov (United States)

    Kaden, Volker; Lange, Elke; Küster, Heike; Müller, Thomas; Lange, Bodo

    2010-07-14

    The RIEMSER Schweinepestoralvakzine is an attenuated vaccine for oral vaccination of wild boar against classical swine fever (CSF). The safety of this licensed bait vaccine which is based on the CSF virus (CSFV) strain "C" was investigated in eight animal species, e.g. weaner pigs (n=111), wild boar (n=11), ruminants (cattle, goats and sheep, n=11), foxes (n=5), rabbits (n=12), and mice (n=10). Animals were vaccinated either with a single vaccine dose containing at least 10(4.5) TCID(50), or with overdoses, i.e. the 10-fold dose, or they were subjected to repeated application schemes. During the entire observation period none of the animals which were given the vaccine virus showed clinical signs, with the exception of rabbits. These reacted to the vaccination with fever. Orally vaccinated pigs did not transmit vaccine virus to susceptible contact animals (sentinels). In none of the species examined neither vaccine virus nor viral RNA could be detected in blood after vaccination. In one wild boar viral RNA could be established in the tonsil 21 days post-vaccination (dpv); all other organ samples tested virologically negative. Up to 77.5% of the pigs and wild boar developed virus neutralising antibodies (VNA) already 14 dpv. The mean VNA titres observed in the vaccination groups seemed to depend rather on individual factors than on the administered virus dose (virus titre per dose) or the vaccination scheme. These results are comparable with findings obtained during oral vaccination campaigns in wild boar and after parenteral vaccination with this C-strain virus. From the results presented here it can be concluded that RIEMSER Schweinepestoralvakzine is safe for target and non-target species. PMID:20022716

  19. Attenuation of CCl4-induced hepatic fibrosis in mice by vaccinating against TGF-β1.

    Directory of Open Access Journals (Sweden)

    Xiaobao Fan

    Full Text Available Transforming growth factor β1 (TGF-β1 is the pivotal pro-fibrogenic cytokine in hepatic fibrosis. Reducing the over-produced expression of TGF-β1 or blocking its signaling pathways is considered to be a promising therapeutic strategy for hepatic fibrosis. In this study, we evaluated the feasibility of attenuating hepatic fibrosis by vaccination against TGF-β1 with TGF-β1 kinoids. Two TGF-β1 kinoid vaccines were prepared by cross-linking TGF-β1-derived polypeptides (TGF-β1(25-[41-65] and TGF-β1(30-[83-112] to keyhole limpet hemocyanin (KLH. Immunization with the two TGF-β1 kinoids efficiently elicited the production of high-levels of TGF-β1-specific antibodies against in BALB/c mice as tested by enzyme-linked immunosorbent assay (ELISA and Western blotting. The antisera neutralized TGF-β1-induced growth-inhibition on mink lung epithelial cells (Mv1Lu and attenuated TGF-β1-induced Smad2/3 phosphorylation, α-SMA, collagen type 1 alpha 2 (COL1A2, plasminogen activator inhibitor-1 (PAI-1 and tissue inhibitor of metalloproteinase-1 (TIMP-1 expression in the rat hepatic stellate cell (HSC line, HSC-T6. Vaccination against TGF-β1 with the kinoids significantly suppressed CCl4-induced collagen deposition and the expression of α-SMA and desmin, attenuated hepatocyte apoptosis and accelerated hepatocyte proliferation in BALB/c mice. These results demonstrated that immunization with the TGF-β1 kinoids efficiently attenuated CCl4-induced hepatic fibrosis and liver injury. Our study suggests that vaccination against TGF-β1 might be developed into a feasible therapeutic approach for the treatment of chronic fibrotic liver diseases.

  20. Nanovaccines: recent developments in vaccination

    Indian Academy of Sciences (India)

    Tarala D Nandedkar

    2009-12-01

    In the past 100 years, vaccination has contributed immensely to public health by preventing a number of infectious diseases. Attenuated, killed or part of the microorganism is employed to stimulate the immune system against it. Progress in biotechnology has provided protective immunity through DNA vaccines. In recent years, nanovaccine is a novel approach to the methodology of vaccination. Nanomaterials are delivered in the form of microspheres, nanobeads or micro-nanoprojections. Painless, effective and safe needle-free routes such as the intranasal or the oral route, or patches of microprojections to the skin are some of the approaches which are in the experimental stage at present but may have a great future ahead in nanovaccination.

  1. Challenges for cancer vaccine development.

    Science.gov (United States)

    Tabi, Z; Man, S

    2006-10-01

    The first generation of human cancer vaccines has been tested in phase III clinical trials, but only a few of these have demonstrated sufficient efficacy to be licensed for clinical use. This article reviews some of the mechanisms that could contribute to these limited clinical responses, and highlights the challenges faced for development of future vaccines. PMID:16979786

  2. Development of a schistosomiasis vaccine.

    Science.gov (United States)

    Molehin, Adebayo J; Rojo, Juan U; Siddiqui, Sabrina Z; Gray, Sean A; Carter, Darrick; Siddiqui, Afzal A

    2016-05-01

    Schistosomiasis is a neglected tropical disease (NTD) of public health importance. Despite decades of implementation of mass praziquantel therapy programs and other control measures, schistosomiasis has not been contained and continues to spread to new geographic areas. A schistosomiasis vaccine could play an important role as part of a multifaceted control approach. With regards to vaccine development, many biological bottlenecks still exist: the lack of reliable surrogates of protection in humans; immune interactions in co-infections with other diseases in endemic areas; the potential risk of IgE responses to antigens in endemic populations; and paucity of appropriate vaccine efficacy studies in nonhuman primate models. Research is also needed on the role of modern adjuvants targeting specific parts of the innate immune system to tailor a potent and protective immune response for lead schistosome vaccine candidates with the long-term aim to achieve curative worm reduction. This review summarizes the current status of schistosomiasis vaccine development. PMID:26651503

  3. Studies on the immune response of previously infected lambs to vaccination with the radiation attenuated Dictyocaulus filaria vaccine

    International Nuclear Information System (INIS)

    The immune response of lambs infected with the lungworm, Dictyocaulus filaria to vaccination with the radiation attenuated D.filaria vaccine was studied under experimental conditions. Healthy, un-infected lambs, 4-6 months of age were randomly distributed into three groups. Group one lambs were previously exposed to single or trickle infections of D.filaria before being vaccinated, group two lambs were vaccinated only whereas the group three lambs received neither infection nor were vaccinated. All the lambs were subsequently challanged with normal infective D.filaria larvae. The results of the experiment indicate that the vaccine confers very little or practically no immunity in lambs already exposed to the infection. The significance of these findings in the use of the vaccine for the control of lungworm disease in sheep under field conditions is discussed. (author)

  4. Status of vaccine research and development for enterotoxigenic Escherichia coli.

    Science.gov (United States)

    Bourgeois, A Louis; Wierzba, Thomas F; Walker, Richard I

    2016-06-01

    Enterotoxigenic Escherichia coli (ETEC) is one of the most common bacterial causes of diarrhea-associated morbidity and mortality, particularly among infants and young children in developing countries. Still, the true impact on child and traveler health is likely underestimated. There are currently no licensed vaccines for ETEC, but studies indicate high public health impact, cost-effectiveness, and feasibility of immune protection through vaccination. ETEC vaccine development remains a World Health Organization priority. Traditionally, ETEC vaccine development efforts have focused on inducing antitoxin and anticolonization antigen immunity, as studies indicate that antibodies against both antigen types can contribute to protection and thus have potential for vaccines. Leading cellular vaccine candidates are ETVAX (a mixture of four inactivated strains) and ACE527 (a mixture of three live attenuated strains), both of which have been found to be safe and immunogenic in Phase 1/2 trials. ETVAX is the furthest along in development with descending-age studies already underway in Bangladesh. Other ETEC vaccine candidates based on protein subunits, toxoids (both LT and ST), or novel, more broadly conserved ETEC antigens are also under development. Of these, a protein adhesin-based subunit approach is the most advanced. Impact and economic models suggest favorable vaccine cost-effectiveness, which may help expand market interest in ETEC vaccines. Combination vaccine formulations may help improve the economic case for development and use, and better point-of-care diagnostics will help to raise awareness of the true health burden of ETEC and highlight the potential public health benefit of ETEC vaccine introduction. Better diagnostics and vaccine demand forecasting will also improve vaccine development financing and support accelerated uptake once a licensed vaccine becomes available. PMID:26988259

  5. Evaluation of regulated delayed attenuation strategies for Salmonella enterica serovar Typhi vaccine vectors in neonatal and infant mice.

    Science.gov (United States)

    Shi, Huoying; Wang, Shifeng; Curtiss, Roy

    2013-06-01

    We developed regulated delayed attenuation strategies for Salmonella vaccine vectors. In this study, we evaluated the combination of these strategies in recombinant attenuated Salmonella enterica serovar Typhi and Salmonella enterica serovar Typhimurium vaccine vectors with similar genetic backgrounds in vitro and in vivo. Our goal is to develop a vaccine to prevent Streptococcus pneumoniae infection in newborns; thus, all strains delivered a pneumococcal antigen PspA and the impact of maternal antibodies was evaluated. The results showed that all strains with the regulated delayed attenuated phenotype (RDAP) displayed an invasive ability stronger than that of the S. Typhi vaccine strain, Ty21a, but weaker than that of their corresponding wild-type parental strains. The survival curves of different RDAP vaccine vectors in vitro and in vivo exhibited diverse regulated delayed attenuation kinetics, which was different from S. Typhi Ty21a and the wild-type parental strains. Under the influence of maternal antibody, the persistence of the S. Typhimurium RDAP strain displayed a regulated delayed attenuation trend in nasal lymphoid tissue (NALT), lung, and Peyer's patches, while the persistence of S. Typhi RDAP strains followed the curve only in NALT. The bacterial loads of S. Typhi RDAP strains were lower in NALT, lung, and Peyer's patches in mice born to immune mothers than in those born to naive mothers. In accordance with these results, RDAP vaccine strains induced high titers of IgG antibodies against PspA and against Salmonella lipopolysaccharides. Immunization of mothers with S. Typhi RDAP strains enhanced the level of vaginal mucosal IgA, gamma interferon (IFN-γ), and interleukin 4 (IL-4) and resulted in a higher level of protection against S. pneumoniae challenge. PMID:23616408

  6. Spray application of live attenuated F Strain-derived Mycoplasma gallisepticum vaccines

    Science.gov (United States)

    Live attenuated vaccines (LAVs) are commonly utilized to protect commercial table egg producers from economic losses associated with challenges by the respiratory pathogen Mycoplasma gallisepticum (MG). Currently there are four MG LAVs commercially available within the United States. Consistent am...

  7. A live attenuated Salmonella enterica serovar Typhimurium vaccine provides cross-protection against Salmonella serovars to reduce disease severity and pathogen transmission

    Science.gov (United States)

    A live attenuated Salmonella enterica serovar Typhimurium vaccine was developed to confer broad protection against multiple Salmonella serovars to prevent disease and reduce pathogen colonization and shedding. Two vaccine trials were performed in swine to determine the protection afforded by the vac...

  8. Priorities for CMV vaccine development.

    Science.gov (United States)

    Krause, Philip R; Bialek, Stephanie R; Boppana, Suresh B; Griffiths, Paul D; Laughlin, Catherine A; Ljungman, Per; Mocarski, Edward S; Pass, Robert F; Read, Jennifer S; Schleiss, Mark R; Plotkin, Stanley A

    2013-12-17

    A multidisciplinary meeting addressed priorities related to development of vaccines against cytomegalovirus (CMV), the cause of congenital CMV (cCMV) disease and of serious disease in the immunocompromised. Participants discussed optimal uses of a CMV vaccine, aspects of clinical study design, and the value of additional research. A universal childhood CMV vaccine could potentially rapidly reduce cCMV disease, as infected children are sources of viral transmission to seronegative and seropositive mothers. A vaccine administered to adolescents or adult women could also reduce cCMV disease by making them immune prior to pregnancy. Clinical trials of CMV vaccines in women should evaluate protection against cCMV infection, an essential precursor of cCMV disease, which is a more practical and acceptable endpoint for assessing vaccine effects on maternal-fetal transmission. Clinical trials of vaccines to evaluate prevention of CMV disease in stem cell transplant recipients could use CMV viremia at a level triggering pre-emptive antiviral therapy as an endpoint, because widespread use of pre-emptive and prophylactic antivirals has rendered CMV-induced disease too rare to be a practical endpoint for clinical trials. In solid organ transplant patients, CMV-associated disease is sufficiently common for use as a primary endpoint. Additional research to advance CMV vaccine development should include identifying factors that predict fetal loss due to CMV, determining age-specific incidence and transmission rates, defining the mechanism and relative contributions of maternal reactivation and re-infection to cCMV disease, developing assays that can distinguish between reactivation and re-infection in seropositive vaccinees, further defining predictors of sequelae from cCMV infection, and identifying clinically relevant immune response parameters to CMV (including developing validated assays that could assess CMV antibody avidity) that could lead to the establishment of immune

  9. Inactivated or Live-Attenuated Bivalent Vaccines That Confer Protection against Rabies and Ebola Viruses ▿

    OpenAIRE

    Blaney, Joseph E.; Wirblich, Christoph; Papaneri, Amy B.; Johnson, Reed F.; Myers, Carey J.; Terry L Juelich; Holbrook, Michael R.; Freiberg, Alexander N.; Bernbaum, John G.; Peter B. Jahrling; Paragas, Jason; Schnell, Matthias J.

    2011-01-01

    The search for a safe and efficacious vaccine for Ebola virus continues, as no current vaccine candidate is nearing licensure. We have developed (i) replication-competent, (ii) replication-deficient, and (iii) chemically inactivated rabies virus (RABV) vaccines expressing Zaire Ebola virus (ZEBOV) glycoprotein (GP) by a reverse genetics system based on the SAD B19 RABV wildlife vaccine. ZEBOV GP is efficiently expressed by these vaccine candidates and is incorporated into virions. The vaccine...

  10. Comparative genomics of the Mycobacterium signaling architecture and implications for a novel live attenuated Tuberculosis vaccine.

    Science.gov (United States)

    Zhou, Peifu; Xie, Jianping

    2014-01-01

    Tuberculosis (TB), caused by Mycobacterium tuberculosis (M.tb), remains a major threat to global public health. A new TB vaccine affording superior immune protection to M. bovis Bacillus Calmette-Guérin (BCG) is imperative. The advantage of a live attenuated vaccine is that it can mimic the bona fide pathogen, elicit immune responses similar to natural infection, and potentially provide more protection than other vaccines. BCG, the only vaccine and a live attenuated vaccine that is the result of cumulative mutations by serial passage of M. bovis, has provided clues for the construction of novel improved vaccines. A strategy is put forward for identifying a new live attenuated TB vaccine generated by cumulative mutation based on M.tb. Given the important role of the M.tb signaling network consisting of a two-component system, eukaryotic-like Ser/Thr protein kinase system and sigma factor system based on comparisons among M.tb H37Rv, M. bovis, and BCG, we have put a premium on this signaling circuit as the starting point for the generation of an attenuated TB vaccine. PMID:24013364

  11. Association of IDDM and attenuated response of 2',5'-oligoadenylate synthetase to yellow fever vaccine

    DEFF Research Database (Denmark)

    Bonnevie-Nielsen, V; Larsen, M L; Frifelt, J J;

    1989-01-01

    Basal and yellow fever vaccination-induced 2',5'-oligoadenylate synthetase (2',5'A) activity was determined in blood mononuclear cells (peripheral blood lymphocytes [PBLs]) from insulin-dependent diabetes mellitus (IDDM) and matched control subjects. The live attenuated yellow fever vaccine repre...

  12. Methods to Evaluate the Preclinical Safety and Immunogenicity of Genetically Modified Live-Attenuated Leishmania Parasite Vaccines.

    Science.gov (United States)

    Gannavaram, Sreenivas; Bhattacharya, Parna; Dey, Ranadhir; Ismail, Nevien; Avishek, Kumar; Salotra, Poonam; Selvapandiyan, Angamuthu; Satoskar, Abhay; Nakhasi, Hira L

    2016-01-01

    Live-attenuated parasite vaccines are being explored as potential vaccine candidates since other approaches of vaccination have not produced an effective vaccine so far. In order for live-attenuated parasite vaccines to be tested in preclinical studies and possibly in clinical studies, the safety and immunogenicity of these organisms must be rigorously evaluated. Here we describe methods to test persistence in the immunized host and immunogenicity, and to identify biomarkers of vaccine safety and efficacy with particular reference to genetically attenuated Leishmania parasites. PMID:27076157

  13. Prime-Boost Immunization Using a DNA Vaccine Delivered by Attenuated Salmonella enterica Serovar Typhimurium and a Killed Vaccine Completely Protects Chickens from H5N1 Highly Pathogenic Avian Influenza Virus▿

    OpenAIRE

    Pan, Zhiming; Zhang, Xiaoming; Geng, Shizhong; Fang, Qiang; You, Meng; Zhang, Lei; Jiao, Xinan; Liu, Xiufan

    2010-01-01

    H5N1 highly pathogenic avian influenza virus (HPAIV) has posed a great threat not only for the poultry industry but also for human health. However, an effective vaccine to provide a full spectrum of protection is lacking in the poultry field. In the current study, a novel prime-boost vaccination strategy against H5N1 HPAIV was developed: chickens were first orally immunized with a hemagglutinin (HA) DNA vaccine delivered by attenuated Salmonella enterica serovar Typhimurium, and boosting with...

  14. Long-term safety assessment of live attenuated tetravalent dengue vaccines: deliberations from a WHO technical consultation.

    Science.gov (United States)

    Bentsi-Enchill, Adwoa D; Schmitz, Julia; Edelman, Robert; Durbin, Anna; Roehrig, John T; Smith, Peter G; Hombach, Joachim; Farrar, Jeremy

    2013-05-28

    Dengue is a rapidly growing public health threat with approximately 2.5 billion people estimated to be at risk. Several vaccine candidates are at various stages of pre-clinical and clinical development. Thus far, live dengue vaccine candidates have been administered to several thousands of volunteers and were well-tolerated, with minimal short-term safety effects reported in Phase I and Phase II clinical trials. Based on the natural history of dengue, a theoretical possibility of an increased risk of severe dengue as a consequence of vaccination has been hypothesized but not yet observed. In October 2011, the World Health Organization (WHO) convened a consultation of experts in dengue, vaccine regulation and vaccine safety to review the current scientific evidence regarding safety concerns associated with live attenuated dengue vaccines and, in particular, to consider methodological approaches for their long-term evaluation. In this paper we summarize the scientific background and methodological considerations relevant to the safety assessment of these vaccines. Careful planning and a coordinated approach to safety assessment are recommended to ensure adequate long-term evaluation of dengue vaccines that will support their introduction and continued use. PMID:23570986

  15. Intranasal live attenuated seasonal influenza vaccine: does not challenge current practice.

    Science.gov (United States)

    2013-09-01

    Influenza vaccination of children is only justified when there is a risk of serious influenza complications. In 2012, a live attenuated vaccine for intranasal administration was authorised in the European Union for influenza prevention in individuals aged from 2 to less than 18 years. This type of vaccine has been available in the United States since 2003. Clinical evaluation of this live vaccine is based on three non-inferiority trials versus an injected inactivated vaccine. There are no specific trials in children at risk of serious influenza complications. Only one of these trials was double-blinded. Two trials involved children with a history of respiratory problems. Symptomatic influenza confirmed by viral culture was less frequent in these three trials after intranasal vaccination than after injection of the conventional vaccine (about 3 to 5% and 6 to 10%, respectively). There was no difference between the vaccines in terms of clinical complications of influenza, especially asthma exacerbations. Adverse effects attributed to the intranasal vaccine mainly consisted of local reactions such as rhinorrhoea and nasal congestion, as well as flu-like syndromes. Wheezing, respiratory tract infections and hospitalisation were more frequent with the intranasal vaccine than with the injected vaccine in children aged less than 1 year and in children with a history of severe respiratory illness. The intranasal vaccine is contraindicated in these children. The intranasal vaccine contains live attenuated virus strains and is therefore contraindicated in immunocompromised patients. US pharmacovigilance data suggest that severe allergic reactions to the intranasal vaccine, Guillain-Barré syndrome, and transmission of vaccine viruses to contacts are very rare. Intranasal administration seems to be more practical, especially for children. In practice, there is no firm evidence that this live attenuated influenza vaccine has any clinical advantages over injected vaccines

  16. Efficacy of a live attenuated vaccine in classical swine fever virus postnatally persistently infected pigs.

    Science.gov (United States)

    Muñoz-González, Sara; Perez-Simó, Marta; Muñoz, Marta; Bohorquez, José Alejandro; Rosell, Rosa; Summerfield, Artur; Domingo, Mariano; Ruggli, Nicolas; Ganges, Llilianne

    2015-01-01

    Classical swine fever (CSF) causes major losses in pig farming, with various degrees of disease severity. Efficient live attenuated vaccines against classical swine fever virus (CSFV) are used routinely in endemic countries. However, despite intensive vaccination programs in these areas for more than 20 years, CSF has not been eradicated. Molecular epidemiology studies in these regions suggests that the virus circulating in the field has evolved under the positive selection pressure exerted by the immune response to the vaccine, leading to new attenuated viral variants. Recent work by our group demonstrated that a high proportion of persistently infected piglets can be generated by early postnatal infection with low and moderately virulent CSFV strains. Here, we studied the immune response to a hog cholera lapinised virus vaccine (HCLV), C-strain, in six-week-old persistently infected pigs following post-natal infection. CSFV-negative pigs were vaccinated as controls. The humoral and interferon gamma responses as well as the CSFV RNA loads were monitored for 21 days post-vaccination. No vaccine viral RNA was detected in the serum samples and tonsils from CSFV postnatally persistently infected pigs for 21 days post-vaccination. Furthermore, no E2-specific antibody response or neutralising antibody titres were shown in CSFV persistently infected vaccinated animals. Likewise, no of IFN-gamma producing cell response against CSFV or PHA was observed. To our knowledge, this is the first report demonstrating the absence of a response to vaccination in CSFV persistently infected pigs. PMID:26159607

  17. Mucosal DNA vaccination with highly attenuated Shigella is superior to attenuated Salmonella and comparable to intramuscular DNA vaccination for T cells against HIV.

    Science.gov (United States)

    Vecino, William H; Morin, Paul M; Agha, Rabia; Jacobs, William R; Fennelly, Glenn J

    2002-07-01

    An immunization strategy using attenuated bacteria to deliver DNA vaccine plasmids to mucosal sites may induce protective T cell responses against sexual HIV transmission. In a murine intranasal (i.n.) immunization model, we demonstrate that transiently persistent Deltaasd Shigella flexneri strain 15D harboring DNA vaccines induces HIV- and SIV-specific gamma interferon (IFN-gamma) producing CD8+ T cells among splenocytes more efficiently than either a longer persisting DeltaaroD Salmonella typhimurium strain SL7207 or transiently persistent S. typhi strain Ty21a harboring DNA vaccines. Also, the frequency of antigen-specific gamma interferon (IFN-gamma) producing cells induced by Shigella 15D harboring a DNA vaccine were comparable to that induced by intramuscular (i.m.) immunization with purified DNA vaccine. Moreover, the magnitude of mucosal and systemic antigen-specific IgA and IgG responses after immunization were dependent upon the route (i.m. vs. i.n.) of inoculation, with i.n. Shigella 15D DNA vaccines generating higher levels of HIV-specific IgA in vaginal washings than i.m. purified DNA vaccine. Deltaasd S. flexneri is a promising vector for mucosal DNA vaccine immunization against HIV. PMID:12036602

  18. 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

  19. Mycobacterium tuberculosis virulence: insights and impact on vaccine development.

    Science.gov (United States)

    Delogu, Giovanni; Provvedi, Roberta; Sali, Michela; Manganelli, Riccardo

    2015-01-01

    The existing TB vaccine, the attenuated Mycobacterium bovis strain BCG, is effective in protecting infants from severe forms of the disease, while its efficacy in protecting adults from pulmonary TB is poor. In the last two decades, a renewed interest in TB resulted in the development of several candidate vaccines that are now entering clinical trials. However, most of these vaccines are based on a common rationale and aim to induce a strong T-cell response against Mycobacterium tuberculosis. Recent advancements in the understanding of M. tuberculosis virulence determinants and associated pathogenic strategies are opening a new and broader view of the complex interaction between this remarkable pathogen and the human host, providing insights at molecular level that could lead to a new rationale for the design of novel antitubercular vaccines. A vaccination strategy that simultaneously targets different steps in TB pathogenesis may result in improved protection and reduced TB transmission. PMID:26119086

  20. A live attenuated vaccine for Lassa fever made by reassortment of Lassa and Mopeia viruses.

    Science.gov (United States)

    Lukashevich, Igor S; Patterson, Jean; Carrion, Ricardo; Moshkoff, Dmitry; Ticer, Anysha; Zapata, Juan; Brasky, Kathleen; Geiger, Robert; Hubbard, Gene B; Bryant, Joseph; Salvato, Maria S

    2005-11-01

    Lassa virus (LASV) and Mopeia virus (MOPV) are closely related Old World arenaviruses that can exchange genomic segments (reassort) during coinfection. Clone ML29, selected from a library of MOPV/LASV (MOP/LAS) reassortants, encodes the major antigens (nucleocapsid and glycoprotein) of LASV and the RNA polymerase and zinc-binding protein of MOPV. Replication of ML29 was attenuated in guinea pigs and nonhuman primates. In murine adoptive-transfer experiments, as little as 150 PFU of ML29 induced protective cell-mediated immunity. All strain 13 guinea pigs vaccinated with clone ML29 survived at least 70 days after LASV challenge without either disease signs or histological lesions. Rhesus macaques inoculated with clone ML29 developed primary virus-specific T cells capable of secreting gamma interferon in response to homologous MOP/LAS and heterologous MOPV and lymphocytic choriomeningitis virus. Detailed examination of two rhesus macaques infected with this MOPV/LAS reassortant revealed no histological lesions or disease signs. Thus, ML29 is a promising attenuated vaccine candidate for Lassa fever. PMID:16254329

  1. A Live Attenuated Vaccine for Lassa Fever Made by Reassortment of Lassa and Mopeia Viruses

    Science.gov (United States)

    Lukashevich, Igor S.; Patterson, Jean; Carrion, Ricardo; Moshkoff, Dmitry; Ticer, Anysha; Zapata, Juan; Brasky, Kathleen; Geiger, Robert; Hubbard, Gene B.; Bryant, Joseph; Salvato, Maria S.

    2005-01-01

    Lassa virus (LASV) and Mopeia virus (MOPV) are closely related Old World arenaviruses that can exchange genomic segments (reassort) during coinfection. Clone ML29, selected from a library of MOPV/LASV (MOP/LAS) reassortants, encodes the major antigens (nucleocapsid and glycoprotein) of LASV and the RNA polymerase and zinc-binding protein of MOPV. Replication of ML29 was attenuated in guinea pigs and nonhuman primates. In murine adoptive-transfer experiments, as little as 150 PFU of ML29 induced protective cell-mediated immunity. All strain 13 guinea pigs vaccinated with clone ML29 survived at least 70 days after LASV challenge without either disease signs or histological lesions. Rhesus macaques inoculated with clone ML29 developed primary virus-specific T cells capable of secreting gamma interferon in response to homologous MOP/LAS and heterologous MOPV and lymphocytic choriomeningitis virus. Detailed examination of two rhesus macaques infected with this MOPV/LAS reassortant revealed no histological lesions or disease signs. Thus, ML29 is a promising attenuated vaccine candidate for Lassa fever. PMID:16254329

  2. Effect of Dosage and Vaccination Route on Transmission of a Live Attenuated Mycoplasma gallesepticum Vaccine: A Broiler Model

    Science.gov (United States)

    Mycoplasma gallisepticum (MG) is an economically significant pathogen of poultry species and among the table egg sector of the poultry industry, live attenuated strains of MG are commonly utilized to limit production losses associated with MG-induced disease. The vaccine, however, may be problemati...

  3. Recent update in HIV vaccine development

    OpenAIRE

    Shin, So Youn

    2016-01-01

    Despite the tremendous efforts to develop a successful human immunodeficiency virus (HIV) vaccine, the quest for a safe and effective HIV vaccine seems to be remarkably long and winding. Disappointing results from previous clinical trials of VaxGen's AIDSVAXgp120 vaccine and MRKAd5 HIV-1 Gag/Pol/Nef vaccine emphasize that understanding the correlates of immune protection in HIV infection is the key to solve the puzzle. The modest vaccine efficacy from RV144 trial and the successive results ob...

  4. Oral Vaccination of Channel Catfish against Enteric Septicemia of Catfish Using a Live Attenuated Edwardsiella ictaluri Isolate.

    Science.gov (United States)

    Wise, David J; Greenway, Terrence E; Byars, Todd S; Griffin, Matt J; Khoo, Lester H

    2015-06-01

    Enteric septicemia of catfish (ESC), caused by Edwardsiella ictaluri, is the most problematic bacterial disease affecting catfish aquaculture in the southeastern United States. Efforts to develop an effective ESC vaccine have had limited industrial success. In commercial settings, ESC vaccines are typically administered by immersion when fry are transferred from the hatchery to rearing ponds. While this approach is a practical method of mass delivery, this strategy administers vaccines to very young fish, which lack a fully developed immune system. To circumvent this limitation, an oral vaccination strategy was evaluated as a means of immunizing catfish at the fingerling stage of production, when fish possess a more complete immune arsenal. A virulent E. ictaluri isolate (S97-773) was attenuated by successive passage on media containing increasing concentrations of rifamycin. In laboratory trials, cultured vaccine was diluted and mixed with feed (100 mL diluted vaccine/454 g feed). This mixture was then fed to Channel Catfish Ictalurus punctatus fingerlings. Two separate dilutions of cultured vaccine (1:10 and 1:100) were used to create the vaccine-feed mixture, equating to estimated doses of 5 × 10⁷ and 5 × 10⁶ CFU/g of feed, respectively. After 30 d, catfish were exposed by immersion (1 × 10⁶ CFU/mL) to the virulent parental strain of E. ictaluri. The target dose (1:100 dilution, ∼5 × 10⁶ CFU/g of feed) offered exceptional protection (relative percent survival = 82.6-100%). In addition, negligible deaths occurred in fish vaccinated at 10 times the target dose (1:10 dilution, ∼5 × 10⁷ CFU/g of feed). In pond trials, antibody production increased 18-fold in orally vaccinated fish. When compared with nonvaccinated controls, vaccination significantly improved survival, feed fed, feed conversion, biomass produced, and total harvest. This research demonstrates Channel Catfish can be successfully immunized in a commercial setting against E. ictaluri

  5. Reverse restriction fragment length polymorphism (RRFLP): A novel technique for genotyping infectious laryngotracheitis virus (ILTV) live attenuated vaccines.

    Science.gov (United States)

    Callison, Scott A; Riblet, Sylva M; Rodríguez-Avila, Andres; García, Maricarmen

    2009-09-01

    A novel technique, the reverse restriction fragment length polymorphism (RRFLP) assay, was developed as a means of detecting specific informative polymorphic sites in the infectious laryngotracheitis virus (ILTV) genome. During the RRFLP procedure, DNA is digested with restriction enzymes targeting an informative polymorphic site and then used as template in a real-time polymerase chain reaction (PCR) with primers flanking the informative region. The analysis of the DeltaC(t) values obtained from digested and undigested template DNA provides the genotype of the DNA. In this study, the RRFLP assay was applied as a method to differentiate between the two types of infectious laryngotracheitis virus attenuated live vaccines. Sequence analysis of ILTV vaccines revealed an informative polymorphic site in the 5'-non-coding region of the infected cell protein (ICP4) gene. Unique AvaI and AlwI restriction enzyme sites were identified in the tissue culture origin and chicken embryo origin attenuated vaccines, respectively. These two informative polymorphic sites were used in a RRFLP assay to genotype rapidly and reproducibly ILTV attenuated live vaccines. PMID:19433109

  6. Generation and Characterization of Live Attenuated Influenza A(H7N9 Candidate Vaccine Virus Based on Russian Donor of Attenuation.

    Directory of Open Access Journals (Sweden)

    Svetlana Shcherbik

    Full Text Available Avian influenza A (H7N9 virus has emerged recently and continues to cause severe disease with a high mortality rate in humans prompting the development of candidate vaccine viruses. Live attenuated influenza vaccines (LAIV are 6:2 reassortant viruses containing the HA and NA gene segments from wild type influenza viruses to induce protective immune responses and the six internal genes from Master Donor Viruses (MDV to provide temperature sensitive, cold-adapted and attenuated phenotypes.LAIV candidate A/Anhui/1/2013(H7N9-CDC-LV7A (abbreviated as CDC-LV7A, based on the Russian MDV, A/Leningrad/134/17/57 (H2N2, was generated by classical reassortment in eggs and retained MDV temperature-sensitive and cold-adapted phenotypes. CDC-LV7A had two amino acid substitutions N123D and N149D (H7 numbering in HA and one substitution T10I in NA. To evaluate the role of these mutations on the replication capacity of the reassortants in eggs, the recombinant viruses A(H7N9RG-LV1 and A(H7N9RG-LV2 were generated by reverse genetics. These changes did not alter virus antigenicity as ferret antiserum to CDC-LV7A vaccine candidate inhibited hemagglutination by homologous A(H7N9 virus efficiently. Safety studies in ferrets confirmed that CDC-LV7A was attenuated compared to wild-type A/Anhui/1/2013. In addition, the genetic stability of this vaccine candidate was examined in eggs and ferrets by monitoring sequence changes acquired during virus replication in the two host models. No changes in the viral genome were detected after five passages in eggs. However, after ten passages additional mutations were detected in the HA gene. The vaccine candidate was shown to be stable in the ferret model; post-vaccination sequence data analysis showed no changes in viruses collected in nasal washes present at day 5 or day 7.Our data indicate that the A/Anhui/1/2013(H7N9-CDC-LV7A reassortant virus is a safe and genetically stable candidate vaccine virus that is now available for

  7. Research Regarding some Live Attenuated Vaccines Used in Immunoprophylaxis of the Avian Infectious Bursitis

    Directory of Open Access Journals (Sweden)

    Emil Tirziu

    2010-10-01

    Full Text Available In our research four live attenuated vaccines against avian infectious bursitis (two inland produced and two imported were tested: Biavac, Biaromvac-Pa, Gumboro Vaccine Nobilis 228e and Live Virus Vaccine Tablets Gumboro, M.B. Strain. The research was made in production conditions on 44,400 broiler chickens maintained in industrial system and raised on bedding and in batteries. The broilers were kept in four poultry houses, each of them representing an experimental group. We mention that vaccines were administered only one time. Vaccines efficiency was assessed by immunoenzymatic test. In that purpose, for each poultry house, 20 broilers were isolated and identified by a tibial ring, their immune response being followed between 5 and 42 days of age. Analyzing the results about individual antibodies titer during the experiment, the significant differences were observed both in poultries and phases. The best results were obtained using Live Virus Vaccine Tablets Gumboro, M.B. strain.

  8. Glycoprotein G deficient infectious laryngotracheitis virus is a candidate attenuated vaccine.

    Science.gov (United States)

    Devlin, Joanne M; Browning, Glenn F; Hartley, Carol A; Gilkerson, James R

    2007-05-01

    Infectious laryngotracheitis virus (ILTV), an alphaherpesvirus, causes respiratory disease in chickens and is currently controlled by vaccination with conventionally attenuated virus strains. These vaccines have limitations because of residual pathogenicity and reversion to virulence, suggesting that a novel vaccine strain that lacks virulence gene(s) may enhance disease control. Glycoprotein G (gG) has recently been identified as a virulence factor in ILTV. In this study the immunogenicity and relative pathogenicity of gG deficient ILTV was investigated in SPF chickens. Birds vaccinated with gG deficient ILTV were protected against clinical signs of disease following challenge with virulent ILTV and gG deficient ILTV was also shown to be less pathogenic than currently available commercial vaccine strains. Thus gG deficient ILTV appears to have potential as a vaccine candidate. PMID:17316926

  9. An update on safety studies on the attenuated ?RIEMSER? Schweinepestoralvakzine? for vaccination of wild boar against classical swine fever

    OpenAIRE

    Kaden, Volker; Lange, Elke; Küster, Heike; Müller, Thomas; Lange, Bodo

    2009-01-01

    Abstract The RIEMSER? Schweinepestoralvakzine is an attenuated vaccine for oral vaccination of wild boar against classical swine fever (CSF). The safety of this licensed bait vaccine which is based on the CSF virus (CSFV) strain ?C? was investigated in 8 animal species, e.g. weaner pigs (n=111), wild boar (n=11), ruminants (cattle, goats and sheep, n=11), foxes (n=5), rabbits (n=12), and mice (n=10). Animals were vaccinated either with a single vaccine dose containing at least 104....

  10. Irradiation-attenuated anti-parasite vaccines in ruminants. Present status and future prospects

    International Nuclear Information System (INIS)

    The only commercially available irradiated anti-parasite vaccine is Dictol, the anti-Dictyocaulus viviparus vaccine, which is still being widely used in cattle 20 years after its introduction. Several other similar helminth vaccines which showed promise early in their development or use have now been abandoned for reasons both scientific and commercial. Nevertheless, there is still active interest in the development of irradiated vaccines for fascioliasis and schistosomiasis, as recent field trials have shown that irradiated metacercarial and schistosomular vaccines are effective against F. hepatica and S. bovis in cattle. There are no commercially available irradiated vaccines against protozoal diseases. Although experiments showed that irradiated vaccines were effective against Babesia bigemina and Theileria parva in cattle, interest in these has waned as other forms of live vaccines have been introduced. Vaccination against African trypanosomiasis remains an intractable problem, because of the multiplicity of naturally occurring antigenically distinct strains. (author)

  11. Alternative Live-Attenuated Influenza Vaccines Based on Modifications in the Polymerase Genes Protect against Epidemic and Pandemic Flu▿

    Science.gov (United States)

    Solórzano, Alicia; Ye, Jianqiang; Pérez, Daniel R.

    2010-01-01

    Human influenza is a seasonal disease associated with significant morbidity and mortality. Influenza vaccination is the most effective means for disease prevention. We have previously shown that mutations in the PB1 and PB2 genes of the live-attenuated influenza vaccine (LAIV) from the cold-adapted (ca) influenza virus A/Ann Arbor/6/60 (H2N2) could be transferred to avian influenza viruses and produce partially attenuated viruses. We also demonstrated that avian influenza viruses carrying the PB1 and PB2 mutations could be further attenuated by stably introducing a hemagglutinin (HA) epitope tag in the PB1 gene. In this work, we wanted to determine whether these modifications would also result in attenuation of a so-called triple reassortant (TR) swine influenza virus (SIV). Thus, the TR influenza A/swine/Wisconsin/14094/99 (H3N2) virus was generated by reverse genetics and subsequently mutated in the PB1 and PB2 genes. Here we show that a combination of mutations in this TR backbone results in an attenuated virus in vitro and in vivo. Furthermore, we show the potential of our TR backbone as a vaccine that provides protection against the 2009 swine-origin pandemic influenza H1N1 virus (S-OIV) when carrying the surface of a classical swine strain. We propose that the availability of alternative backbones to the conventional ca A/Ann Arbor/6/60 LAIV strain could also be useful in epidemic and pandemic influenza and should be considered for influenza vaccine development. In addition, our data provide evidence that the use of these alternative backbones could potentially circumvent the effects of original antigenic sin (OAS) in certain circumstances. PMID:20181702

  12. Developing Anti-tick Vaccines.

    Science.gov (United States)

    Rodríguez-Mallon, Alina

    2016-01-01

    Ticks are responsible for the transmission of viral, bacterial, and protozoal diseases of man and animals and also produce significant economic losses to cattle industry. The use of acaricides constitutes a major component of integrated tick control strategies. However, this is accompanied by the selection of acaricide-resistant ticks and contamination of environment and milk and meat products with drug residues. These issues highlight the need for alternative approaches to control tick infestations and have triggered the search for tick protective antigens for vaccine development. Vaccination as a tick control method has been practiced since the introduction of TickGARD and Gavac that were developed using the midgut glycoprotein Bm86 as antigen. Gavac within integrated tick management systems has proven to reduce the number of acaricidal applications per year that are required to control some strains of R. microplus ticks in different geographical regions. Nevertheless, it has limited or no efficacy against other tick species. These issues have stimulated research for additional tick protective antigens with critical functions in the tick. This chapter presents methodologies for the design and test of molecules as antigens against ticks. Considerations about different methods for the tick control compared to the immunological methods, the desirable characteristics for an anti-tick vaccine and the obstacles encountered for developing this kind of vaccines are discussed. Detailed methodologies for the establishment of a biological model to test new molecules as immunogens against ticks and to perform challenge trials with this model are presented. General considerations in the efficacy calculation for any anti-tick vaccine are also discussed. PMID:27076303

  13. DNA vaccines: a review of developments.

    Science.gov (United States)

    Webster, R G; Robinson, H L

    1997-10-01

    Immunisation with purified DNA is a powerful technique for inducing immune responses. The concept is very simple, involving insertion of the gene encoding the antigen of choice into a bacterial plasmid, and injection of the plasmid into the host where the antigen is expressed and induces humoral and cellular immunity. This technology can induce immunity to all antigens that can be encoded by DNA; this includes all protein, but not carbohydrate, antigens. DNA immunisation appears to result in presentation of antigens to the host's immune system in a natural form, similar to that achieved with live attenuated vaccines. The most efficacious routes for DNA immunisation are bombardment with particles coated with DNA (gene-gun), followed by intramuscular and intradermal administration. The efficiency of transfection of host cells is low, but sufficient to induce immunological responsiveness. The DNA plasmid is retained in the transfected cells in an unintegrated form for the life of the cell. The majority of transfected cells are eliminated, but residual expression has been detected for longer periods. In animal model systems, DNA immunisation has been shown to induce protective immunity to influenza, herpes, rabies, hepatitis B and lymphocytic choriomeningitis viruses, and to malaria and mycobacteria. However, strategies to induce protective immunity to HIV and other disease agents remain to be developed. DNA vaccines permit modulation of the immune response by altering the route or method of DNA administration, by including immunostimulatory sequences in the plasmid, and by co-administration of cytokine genes with the gene encoding the antigen of interest. A T helper 1 response provides cell-mediated immune killing of infected cells and neutralising antibody production, while a T helper 2 response induces IgE and allergic responses. The advantages of DNA immunisation are: similarity to live attenuated vaccination but without the possibility of contamination with

  14. Macaques vaccinated with live-attenuated SIV control replication of heterologous virus

    OpenAIRE

    Reynolds, Matthew R.; Weiler, Andrea M.; Weisgrau, Kim L.; Piaskowski, Shari M.; Furlott, Jessica R.; Weinfurter, Jason T.; Kaizu, Masahiko; Soma, Taeko; León, Enrique J.; MacNair, Caitlin; Leaman, Dan P.; Zwick, Michael B.; Gostick, Emma; Musani, Solomon K.; Price, David A.

    2008-01-01

    An effective AIDS vaccine will need to protect against globally diverse isolates of HIV. To address this issue in macaques, we administered a live-attenuated simian immunodeficiency virus (SIV) vaccine and challenged with a highly pathogenic heterologous isolate. Vaccinees reduced viral replication by ∼2 logs between weeks 2–32 (P ≤ 0.049) postchallenge. Remarkably, vaccinees expressing MHC-I (MHC class I) alleles previously associated with viral control completely suppressed acute phase repl...

  15. Novel adjuvants & delivery vehicles for vaccines development: a road ahead.

    Science.gov (United States)

    Mohan, Teena; Verma, Priyanka; Rao, D Nageswara

    2013-11-01

    The pure recombinant and synthetic antigens used in modern day vaccines are generally less immunogenic than older style live/attenuated and killed whole organism vaccines. One can improve the quality of vaccine production by incorporating immunomodulators or adjuvants with modified delivery vehicles viz. liposomes, immune stimulating complexes (ISCOMs), micro/nanospheres apart from alum, being used as gold standard. Adjuvants are used to augment the effect of a vaccine by stimulating the immune system to respond to the vaccine, more vigorously, and thus providing increased immunity to a particular disease. Adjuvants accomplish this task by mimicking specific sets of evolutionary conserved molecules which include lipopolysaccharides (LPS), components of bacterial cell wall, endocytosed nucleic acids such as dsRNA, ssDNA and unmethylated CpG dinucleotide containing DNA. This review provides information on various vaccine adjuvants and delivery vehicles being developed to date. From literature, it seems that the humoral immune responses have been observed for most adjuvants and delivery platforms while viral-vector, ISCOMs and Montanides have shown cytotoxic T-cell response in the clinical trials. MF59 and MPL® have elicited Th1 responses, and virus-like particles (VLPs), non-degradable nanoparticle and liposomes have also generated cellular immunity. Such vaccine components have also been evaluated for alternative routes of administration with clinical success reported for intranasal delivery of viral-vectors and proteosomes and oral delivery of VLP vaccines. PMID:24434331

  16. Recent advances in the development of vaccines for tuberculosis.

    Science.gov (United States)

    Ahsan, Mohamed Jawed

    2015-05-01

    Tuberculosis (Tb) continues to be a dreadful infection worldwide with nearly 1.5 million deaths in 2013. Furthermore multi/extensively drug-resistant Tb (MDR/XDR-Tb) worsens the condition. Recently approved anti-Tb drugs (bedaquiline and delamanid) have the potential to induce arrhythmia and are recommended in patients with MDR-Tb when other alternatives fail. The goal of elimination of Tb by 2050 will not be achieved without an effective new vaccine. The recent advancement in the development of Tb vaccines is the keen focus of this review. To date, Bacille Calmette Guerin (BCG) is the only licensed Tb vaccine in use, however its efficacy in pulmonary Tb is variable in adolescents and adults. There are nearly 15 vaccine candidates in various phases of clinical trials, includes five protein or adjuvant vaccines, four viral-vectored vaccines, three mycobacterial whole cell or extract vaccines, and one each of the recombinant live and the attenuated Mycobacterium tuberculosis (Mtb) vaccine. PMID:26288734

  17. Advances in the development of vaccines for dengue fever

    Directory of Open Access Journals (Sweden)

    Simmons M

    2012-05-01

    Full Text Available Monika Simmons1, Nimfa Teneza-Mora1, Robert Putnak21Viral and Rickettsial Diseases Department, Naval Medical Research Center, 2Division of Viral Diseases, Walter Reed Army Institute of Research, Silver Spring, MD, USAAbstract: Dengue fever is caused by the mosquito-borne dengue virus (DENV serotypes 1–4, and is the most common arboviral infection of humans in subtropical and tropical regions of the world. There are currently no prophylaxis or treatment options in the form of vaccines or antivirals, leaving vector control the only method of prevention. A particular challenge with DENV is that a successful vaccine has to be effective against all four serotypes without predisposing for antibody-mediated enhanced disease. In this review, we discuss the current lead vaccine candidates in clinical trials, as well as some second-generation vaccine candidates undergoing preclinical evaluation. In addition, we discuss DENV epidemiology, clinical disease and strategies used for Flavivirus antivirals in the past, the development of new DENV therapeutics, and their potential usefulness for prophylaxis and treatment.Keywords: tetravalent dengue vaccine, live attenuated vaccine, purified inactivated vaccine, DNA vaccine, antibody-dependent enhancement, antivirals

  18. Recombinant Swinepox Virus for Veterinary Vaccine Development.

    Science.gov (United States)

    Fan, Hong-Jie; Lin, Hui-Xing

    2016-01-01

    Poxvirus-vectors have been widely used in vaccine development for several important human and animal diseases; some of these vaccines have been licensed and used extensively. Swinepox virus (SPV) is well suited to develop recombinant vaccines because of its large packaging capacity for recombinant DNA, its host range specificity, and its ability to induce appropriate immune responses. PMID:26458836

  19. 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 BACKGROUND: 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. RESULTS: 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. CONCLUSIONS: 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.

  20. Genome sequences of three live attenuated vaccine strains of Brucella species and implications for pathogenesis and differential diagnosis.

    Science.gov (United States)

    Wang, Yufei; Ke, Yuehua; Wang, Zhoujia; Yuan, Xitong; Qiu, Yefeng; Zhen, Qing; Xu, Jie; Li, Tiefeng; Wang, Dali; Huang, Liuyu; Chen, Zeliang

    2012-11-01

    Live attenuated vaccines play essential roles in the prevention of brucellosis. Here, we report the draft genome sequences of three vaccine strains, Brucella melitensis M5-10, B. suis S2-30, and B. abortus 104M. Primary genome sequence analysis identified mutations, deletions, and insertions which have implications for attenuation and signatures for differential diagnosis. PMID:23045513

  1. Genome Sequences of Three Live Attenuated Vaccine Strains of Brucella Species and Implications for Pathogenesis and Differential Diagnosis

    OpenAIRE

    Wang, Yufei; Ke, Yuehua; Wang, Zhoujia; Yuan, Xitong; Qiu, Yefeng; Zhen, Qing; Xu, Jie; Li, Tiefeng; Wang, Dali; Huang, Liuyu; Chen, Zeliang

    2012-01-01

    Live attenuated vaccines play essential roles in the prevention of brucellosis. Here, we report the draft genome sequences of three vaccine strains, Brucella melitensis M5-10, B. suis S2-30, and B. abortus 104M. Primary genome sequence analysis identified mutations, deletions, and insertions which have implications for attenuation and signatures for differential diagnosis.

  2. Multicenter Safety and Immunogenicity Trial of an Attenuated Measles Vaccine for NHP.

    Science.gov (United States)

    Yee, Joann L; McChesney, Michael B; Christe, Kari L

    2015-10-01

    Measles is a highly contagious viral disease in NHP. The infection can range from asymptomatic to rapidly fatal, resulting in significant morbidity and mortality in captive populations. In addition to appropriate quarantine practices, restricted access, the immunization of all personnel in contact with NHP, and the wearing of protective clothing including face masks, measles immunization further reduces the infection risk. Commercially available measles vaccines are effective for use in NHP, but interruptions in their availability have prevented the implementation of ongoing, consistent vaccination programs. This need for a readily available vaccine led us to perform a broad, multicenter safety and immunogenicity study of another candidate vaccine, MVac (Serum Institute of India), a monovalent measles vaccine derived from live Edmonston-Zagreb strain virus that had been attenuated after 22 passages on human diploid cells. PMID:26473350

  3. Recent advances in the study of live attenuated cell-cultured smallpox vaccine LC16m8.

    Science.gov (United States)

    Eto, Akiko; Saito, Tomoya; Yokote, Hiroyuki; Kurane, Ichiro; Kanatani, Yasuhiro

    2015-11-01

    LC16m8 is a live, attenuated, cell-cultured smallpox vaccine that was developed and licensed in Japan in the 1970s, but was not used in the campaign to eradicate smallpox. In the early 2000s, the potential threat of bioterrorism led to reconsideration of the need for a smallpox vaccine. Subsequently, LC16m8 production was restarted in Japan in 2002, requiring re-evaluation of its safety and efficacy. Approximately 50,000 children in the 1970s and about 3500 healthy adults in the 2000s were vaccinated with LC16m8 in Japan, and 153 adults have been vaccinated with LC16m8 or Dryvax in phase I/II clinical trials in the USA. These studies confirmed the safety and efficacy of LC16m8, while several studies in animal models have shown that LC16m8 protects the host against viral challenge. The World Health Organization Strategic Advisory Group of Experts on Immunization recommended LC16m8, together with ACAM2000, as a stockpile vaccine in 2013. In addition, LC16m8 is expected to be a viable alternative to first-generation smallpox vaccines to prevent human monkeypox. PMID:26319072

  4. PRODUCTION OF HOMOLOGOUS LIVE ATTENUATED CELL CULTURE VACCINE FOR THE CONTROL OF PESTE DES PETITS RUMINANTS IN SMALL RUMINANTS

    Directory of Open Access Journals (Sweden)

    M. ASIM, A. RASHID, A. H. CHAUDHARY AND M. S. NOOR

    2009-05-01

    Full Text Available Antibody response of a live-attenuated Peste des Petits Ruminants (PPR cell culture vaccine was studied at Veterinary Research Institute, Lahore, Pakistan. For this purpose, one group of five sheep and 5 goats each was vaccinated subcutaneously with 1 ml reconstituted PPR vaccine and second group of five sheep and 5 goats was inoculated with 1 ml saline solution. Blood samples were collected before and after vaccination, sera were obtained and analyzed for antibodies against PPR by competitive ELISA (cELISA. Findings suggested that antibody titres at day zero, 21 and 45 were 24.762 ± 2.69, 65.467 ± 2.29 and 83.012 ± 2.11 in sheep and 18.723 ± 2.27, 59.162 ± 1.53 and 72.176 ± 2.93 in goats, respectively. No untoward reactions were observed following vaccination. All vaccinated animals developed high titre of antibodies (PI>50.

  5. Status of vaccine research and development for Shigella.

    Science.gov (United States)

    Mani, Sachin; Wierzba, Thomas; Walker, Richard I

    2016-06-01

    Shigella are gram-negative bacteria that cause severe diarrhea and dysentery. In 2013, Shigella infections caused an estimated 34,400 deaths in children less than five years old and, in 2010, an estimated 40,000 deaths in persons older than five years globally. New disease burden estimates from newly deployed molecular diagnostic assays with increased sensitivity suggest that Shigella-associated morbidity may be much greater than previous disease estimates from culture-based methods. Primary prevention of this disease should be based on universal provision of potable water and sanitation methods and improved personal and food hygiene. However, an efficacious and low-cost vaccine would complement and accelerate disease reduction while waiting for universal access to water, sanitation, and hygiene improvements. This review article provides a landscape of Shigella vaccine development efforts. No vaccine is yet available, but human and animal challenge-rechallenge trials with virulent Shigella as well as observational studies in Shigella-endemic areas have shown that the incidence of disease decreases following Shigella infection, pointing to biological feasibility of a vaccine. Immunity to Shigella appears to be strain-specific, so a vaccine that covers the most commonly detected strains (i.e., S. flexneri 2a, 3a, 6, and S. sonnei) or a vaccine using cross-species conserved antigens would likely be most effective. Vaccine development and testing may be accelerated by use of animal models, such as the guinea pig keratoconjunctivitis or murine pneumonia models. Because there is no correlate of protection, however, human studies will be necessary to evaluate vaccine efficacy prior to deployment. A diversity of Shigella vaccine constructs are under development, including live attenuated, formalin-killed whole-cell, glycoconjugate, subunit, and novel antigen vaccines (e.g., Type III secretion system and outer membrane proteins). PMID:26979135

  6. Antibody response in cattle after vaccination with inactivated and attenuated rabies vaccines Resposta imune humoral anti-rábica em bovinos imunizados com vacina inativada e atenuada

    OpenAIRE

    Andréa de Cássia RODRIGUES da SILVA; Caporale, Graciane Maria Medeiros; GONÇALVES Celso Alberto; TARGUETA Mosar Couteiro; Fabiano COMIN; Carlos Roberto ZANETTI; Kotait, Ivanete

    2000-01-01

    Despite the absence of current official reports showing the number of cattle infected by rabies, it is estimated that nearly 30,000 bovines are lost each year in Brazil. In order to minimize the important economic losses, control of the disease is achieved by eliminating bat colonies and by herd vaccination. In this study, we compare the antibody response in cattle elicited by vaccination with an attenuated ERA vaccine (AEvac) and an inactivated-adjuvanted PV (IPVvac) vaccine. The antibody ti...

  7. Evaluation of an attenuated strain of Ehrlichia canis as a vaccine for canine monocytic ehrlichiosis.

    Science.gov (United States)

    Rudoler, Nir; Baneth, Gad; Eyal, Osnat; van Straten, Michael; Harrus, Shimon

    2012-12-17

    Canine monocytic ehrlichiosis is an important tick-borne disease worldwide. No commercial vaccine for the disease is currently available and tick control is the main preventive measure against the disease. The aim of this study was to evaluate the potential of a multi-passaged attenuated strain of Ehrlichia canis to serve as a vaccine for canine monocytic ehrlichiosis, and to assess the use of azithromycin in the treatment of acute ehrlichiosis. Twelve beagle dogs were divided into 3 groups of 4 dogs. Groups 1 and 2 were inoculated (vaccinated) with an attenuated strain of E. canis (#611A) twice or once, respectively. The third group consisted of naïve dogs which served as controls. All 3 groups were challenged with a wild virulent strain of E. canis by administering infected dog-blood intravenously. Transient thrombocytopenia was the only hematological abnormality observed following inoculation of dogs with the attenuated strain. Challenge with the virulent strain resulted in severe disease in all 4 control dogs while only 3 of 8 vaccinated dogs presented mild transient fever. Furthermore, the mean blood rickettsial load was significantly higher in the control group (27-92-folds higher during days 14-19 post challenge with the wild the strain) as compared to the vaccinated dogs. The use of azithromycin was assessed as a therapeutic agent for the acute disease. Four days treatment resulted in further deterioration of the clinical condition of the dogs. Molecular comparison of 4 genes known to express immunoreactive proteins and virulence factors (p30, gp19, VirB4 and VirB9) between the attenuated strain and the challenge wild strain revealed no genetic differences between the strains. The results of this study indicate that the attenuated E. canis strain may serve as an effective and secure future vaccine for canine ehrlichiosis. PMID:23072894

  8. Development and introduction of inactivated poliovirus vaccines derived from Sabin strains in Japan.

    Science.gov (United States)

    Shimizu, Hiroyuki

    2016-04-01

    During the endgame of global polio eradication, the universal introduction of inactivated poliovirus vaccines is urgently required to reduce the risk of vaccine-associated paralytic poliomyelitis and polio outbreaks due to wild and vaccine-derived polioviruses. In particular, the development of inactivated poliovirus vaccines (IPVs) derived from the attenuated Sabin strains is considered to be a highly favorable option for the production of novel IPV that reduce the risk of facility-acquired transmission of poliovirus to the communities. In Japan, Sabin-derived IPVs (sIPVs) have been developed and introduced for routine immunization in November 2012. They are the first licensed sIPVs in the world. Consequently, trivalent oral poliovirus vaccine was used for polio control in Japan for more than half a century but has now been removed from the list of vaccines licensed for routine immunization. This paper reviews the development, introduction, characterization, and global status of IPV derived from attenuated Sabin strains. PMID:25448090

  9. Status of vaccine research and development of vaccines for malaria.

    Science.gov (United States)

    Birkett, Ashley J

    2016-06-01

    Despite recent progress in reducing deaths attributable to malaria, it continues to claim approximately 500,000 lives per year and is associated with approximately 200 million infections. New tools, including safe and effective vaccines, are needed to ensure that the gains of the last 15 years are leveraged toward achieving the ultimate goal of malaria parasite eradication. In 2015, the European Medicines Agency announced the adoption of a positive opinion for the malaria vaccine candidate most advanced in development, RTS,S/AS01, which provides modest protection against clinical malaria; in early 2016, WHO recommended large-scale pilot implementations of RTS,S in settings of moderate-to-high malaria transmission. In alignment with these advancements, the community goals and preferred product characteristics for next-generation vaccines have been updated to inform the development of vaccines that are highly efficacious in preventing clinical malaria, and those needed to accelerate parasite elimination. Next-generation vaccines, targeting all stages of the parasite lifecycle, are in early-stage development with the most advanced in Phase 2 trials. Importantly, progress is being made in the definition of feasible regulatory pathways to accelerate timelines, including for vaccines designed to interrupt transmission of parasites from humans to mosquitoes. The continued absence of financially lucrative, high-income markets to drive investment in malaria vaccine development points to continued heavy reliance on public and philanthropic funding. PMID:26993333

  10. Safety and immunogenicity of a vaccine bait containing ERA strain of attenuated rabies virus.

    OpenAIRE

    Lawson, K F; Black, J G; Charlton, K M; Johnston, D. H.; Rhodes, A. J.

    1987-01-01

    Ninety percent of foxes fed commercial ERA vaccine in a specially designed bait developed rabies serum neutralizing antibodies. The vaccine bait did not cause clinical signs of rabies when consumed by foxes, raccoons, skunks, dogs, cats, cattle and monkeys. When presented, in the laboratory, to wild rodents of the species Microtus, Mus musculus and Peromyscus, the vaccine baits caused vaccine-induced rabies only in Mus musculus. Laboratory mice of the CD-1 and CLL strain were susceptible to v...

  11. Successful respiratory immunization with dry powder live-attenuated measles virus vaccine in rhesus macaques

    OpenAIRE

    Lin, Wen-Hsuan; Griffin, Diane E.; Rota, Paul A.; Papania, Mark; Cape, Stephen P.; Bennett, David; Quinn, Brian; Sievers, Robert E.; Shermer, Charles; Powell, Kenneth; Adams, Robert J.; Godin, Steven; Winston, Scott

    2011-01-01

    Measles remains an important cause of childhood mortality worldwide. Sustained high vaccination coverage is the key to preventing measles deaths. Because measles vaccine is delivered by injection, hurdles to high coverage include the need for trained medical personnel and a cold chain, waste of vaccine in multidose vials and risks associated with needle use and disposal. Respiratory vaccine delivery could lower these barriers and facilitate sustained high coverage. We developed a novel single...

  12. Comparative analysis of the complete genome sequences of two Australian origin live attenuated vaccines of infectious laryngotracheitis virus.

    Science.gov (United States)

    Lee, Sang-Won; Devlin, Joanne M; Markham, John F; Noormohammadi, Amir H; Browning, Glenn F; Ficorilli, Nino P; Hartley, Carol A; Markham, Philip F

    2011-12-01

    Infectious laryngotracheitis virus (ILTV) is an alphaherpesvirus that causes acute respiratory disease in poultry. Live attenuated ILTV vaccines have been used extensively to help control outbreaks of disease. Two Australian-origin attenuated vaccine strains, SA2 and A20 ILTV, are commercially available and are in frequent use in Australia. Both these vaccines are of chicken embryo origin (CEO). The A20 ILTV strain was developed from the SA2 ILTV strain by sequential passage of SA2 ILTV in tissue culture in order to reduce its residual virulence. Previous studies in our laboratories have demonstrated the greater attenuation of A20 ILTV under controlled experimental conditions, but the genetic basis of the in vivo phenotypes of A20 and SA2 ILTV has not been elucidated. In this study, the genetic differences between A20 and SA2 ILTV were examined by performing complete genome sequencing and comparative analysis. The genome sequences were also compared to a reference sequence from another CEO ILTV vaccine (Serva ILTV: GenBank accession number HQ_630064) of European-origin. Additional in ovo studies to assess cell to cell spread were performed in order to allow further comparisons of the pathogenicity of SA2 and A20 ILTV. The sequencing results showed that the genome sizes of SA2 and A20 ILTV were 152,975 and 152,978bp, respectively, while Serva ILTV had a genome size of 152,630bp. The genomes of SA2 and A20 ILTV shared 99.9% nucleotide sequence identity with each other, but only 99.2% identity with Serva ILTV. In complete genome alignments between SA2 and A20 ILTV, a total of 24 single nucleotide polymorphisms (SNPs) were identified, but only two of these were non-synonymous. These were located in the ORF B and UL15 genes. Four indels were detected in non-coding regions. The findings from this study demonstrate the general genetic stability of ILTV, but also show that non-synonymous changes in the ORF B and UL15 genes have arisen following tissue culture passage of SA

  13. A live attenuated cold-adapted influenza A H7N3 virus vaccine provides protection against homologous and heterologous H7 viruses in mice and ferrets

    International Nuclear Information System (INIS)

    The appearance of human infections caused by avian influenza A H7 subtype viruses underscores their pandemic potential and the need to develop vaccines to protect humans from viruses of this subtype. A live attenuated H7N3 virus vaccine was generated by reverse genetics using the HA and NA genes of a low pathogenicity A/chicken/BC/CN-6/04 (H7N3) virus and the six internal protein genes of the cold-adapted A/Ann Arbor/6/60 ca (H2N2) virus. The reassortant H7N3 BC 04 ca vaccine virus was temperature sensitive and showed attenuation in mice and ferrets. Intranasal immunization with one dose of the vaccine protected mice and ferrets when challenged with homologous and heterologous H7 viruses. The reassortant H7N3 BC 04 ca vaccine virus showed comparable levels of attenuation, immunogenicity and efficacy in mice and ferret models. The safety, immunogenicity, and efficacy of this vaccine in mice and ferrets support the evaluation of this vaccine in clinical trials

  14. Vaccination against Canine Distemper Virus Infection in Infant Ferrets with and without Maternal Antibody Protection, Using Recombinant Attenuated Poxvirus Vaccines

    OpenAIRE

    Welter, Janet; Taylor, Jill; Tartaglia, James; Paoletti, Enzo; Stephensen, Charles B.

    2000-01-01

    Canine distemper virus (CDV) infection of ferrets is clinically and immunologically similar to measles, making this a useful model for the human disease. The model was used to determine if parenteral or mucosal immunization of infant ferrets at 3 and 6 weeks of age with attenuated vaccinia virus (NYVAC) or canarypox virus (ALVAC) vaccine strains expressing the CDV hemagglutinin (H) and fusion (F) protein genes (NYVAC-HF and ALVAC-HF) would induce serum neutralizing antibody and protect agains...

  15. A comparative study of live attenuated F strain-derived Mycoplasma gallisepticum vaccines

    Science.gov (United States)

    Commercially available attenuated strains of Mycoplasma gallisepticum (MG) are commonly used within the layer industry to control MG-induced mycoplasmosis. Among these are two live MG vaccines derived from the moderately pathogenic MG “chick F” strain. In the present study, the commercially availa...

  16. Efficacy of Live attenuated and Inactivated Oil Emulsion Infectious Bursal Disease Virus Vaccines in Broiler chicks

    Directory of Open Access Journals (Sweden)

    Nazir Ahmed Lone*, Shafqat Fatima Rehmani1, Taseer Ahmed Khan2 and Shahana Urooj Kazmi3

    2012-10-01

    Full Text Available This study was carried out with the aims to evaluate the efficacy of indigenous live and inactivated Infectious bursal disease virus (IBDV vaccines in broilers. Two hundred and fifty (250, a-day-old broiler chicks divided into five groups (A-E were immunized with live and inactivated vaccine at varying ages. Live vaccine was given to group A (at 8 days post hatch, B (at 8, 15 days post hatch, C (at 8, 15 and 23 days post hatch and D (at 8 days post hatch. In addition group D received a booster dose of inactivated vaccine at 21 days of age, while group E served as control. Antibody titers were measured via Agar Gel Precipitation (AGP test and ELISA, while the degree of protection against the virulent strains of IBDV was also recorded. Results showed that vaccine program adopted for group C and D produced significantly (P<0.05 higher antibody titer as compared to other groups. While a significant (P<0.05 difference in antibody titers was observed between group A and B while no considerable antibodies were detected in group E. The response to challenge dose was recorded as the difference of lesions in bursa, pectoral muscles or other visceral organs with the exception of group C and D. The study suggests that broiler chicks may be vaccinated at days 8, 15 and 23 with live attenuated vaccine or live attenuated vaccine followed by inactivated vaccine at days 8 and 21 that could provide an adequate protection against the virulent form of IBDV.

  17. Room temperature stabilization of oral, live attenuated Salmonella enterica serovar Typhi-vectored vaccines.

    Science.gov (United States)

    Ohtake, Satoshi; Martin, Russell; Saxena, Atul; Pham, Binh; Chiueh, Gary; Osorio, Manuel; Kopecko, Dennis; Xu, Deqi; Lechuga-Ballesteros, David; Truong-Le, Vu

    2011-03-24

    Foam drying, a modified freeze drying process, was utilized to produce a heat-stable, live attenuated Salmonella Typhi 'Ty21a' bacterial vaccine. Ty21a vaccine was formulated with pharmaceutically approved stabilizers, including sugars, plasticizers, amino acids, and proteins. Growth media and harvesting conditions of the bacteria were also studied to enhance resistance to desiccation stress encountered during processing as well as subsequent storage at elevated temperatures. The optimized Ty21a vaccine, formulated with trehalose, methionine, and gelatin, demonstrated stability for approximately 12 weeks at 37°C (i.e., time required for the vaccine to decrease in potency by 1log(10)CFU) and no loss in titer at 4 and 25°C following storage for the same duration. Furthermore, the foam dried Ty21a elicited a similar immunogenic response in mice as well as protection in challenge studies compared to Vivotif™, the commercial Ty21a vaccine. The enhanced heat stability of the Ty21a oral vaccine, or Ty21a derivatives expressing foreign antigens (e.g. anthrax), could mitigate risks of vaccine potency loss during long-term storage, shipping, delivery to geographical areas with warmer climates or during emergency distribution following a bioterrorist attack. Because the foam drying process is conducted using conventional freeze dryers and can be readily implemented at any freeze drying manufacturing facility, this technology appears ready and appropriate for large scale processing of foam dried vaccines. PMID:21300096

  18. Conjugate Meningococcal Vaccines Development: GSK Biologicals Experience

    Directory of Open Access Journals (Sweden)

    Jacqueline M. Miller

    2011-01-01

    Full Text Available Meningococcal diseases are serious threats to global health, and new vaccines specifically tailored to meet the age-related needs of various geographical areas are required. This paper focuses on the meningococcal conjugate vaccines developed by GSK Biologicals. Two combined conjugate vaccines were developed to help protect infants and young children in countries where the incidence of meningococcal serogroup C or serogroup C and Y disease is important: Hib-MenC-TT vaccine, which offers protection against Haemophilus influenzae type b and Neisseria meningitidis serogroup C diseases, is approved in several countries; and Hib-MenCY-TT vaccine, which adds N. meningitidis serogroup Y antigen, is currently in the final stages of development. Additionally, a tetravalent conjugate vaccine (MenACWY-TT designed to help protect against four meningococcal serogroups is presently being evaluated for global use in all age groups. All of these vaccines were shown to be highly immunogenic and to have clinically acceptable safety profiles.

  19. Safety of a Live Attenuated Infectious Bovine Rhinotracheitis Vaccine IBRV LNM Strain

    Institute of Scientific and Technical Information of China (English)

    Guo; Li; Wang; Wei; Zhang; Shuqin; Cheng; Shipeng; Wu; Hua

    2014-01-01

    The paper was to evaluate the vaccine safety,and to prevent public health risk due to virus spread,the approach vaccination of was adopted in this research; and neck intramuscular injection of IBRV LNM attenuated vaccine strain was carried out. Blind passage for three generations in animal has tested the reversion risk to virulence. A total of 14 healthy and weaning cows at 6- 8 month old were divided into three groups. The 1st reversion of virulence trials used 105. 0TCID50/mL neck intramuscular injection of IBRV LNM attenuated vaccine strain. Then,the nose swab samples were collected for continuous 14 days. After passed through 0. 45 μm filter membrane,nasal swabs mixture was prepared as the virulence test inoculum for next generation. The body temperature was detected and clinical observation was carried out for continuous 14 days after inoculation. The inoculation dose was 1ml / cattle. Blood was collected on the 0 and 14 thdays of animal vaccination. After serum isolation,it was used for the antibody detection of serum. Research results showed that no virus was isolated from the nasal swabs from the F2 generation; vaccinated animals did not show any clinical signs of IBR; serological testing of IBRV antibody was negative,which indicated that the strain-inoculated animals did had reversion of virulence in all three generations.

  20. 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.

  1. Status of vaccine research and development of vaccines for tuberculosis.

    Science.gov (United States)

    Evans, Thomas G; Schrager, Lew; Thole, Jelle

    2016-06-01

    TB is now the single pathogen that causes the greatest mortality in the world, at over 1.6 million deaths each year. The widely used the 90 year old BCG vaccine appears to have minimal impact on the worldwide incidence despite some efficacy in infants. Novel vaccine development has accelerated in the past 15 years, with 15 candidates entering human trials; two vaccines are now in large-scale efficacy studies. Modeling by three groups has consistently shown that mass vaccination that includes activity in the latently infected population, especially adolescents and young adults, will likely have the largest impact on new disease transmission. At present the field requires better validated animal models, better understanding of a correlate of immunity, new cost-effective approaches to Proof of Concept trials, and increased appreciation by the public health and scientific community for the size of the problem and the need for a vaccine. Such a vaccine is likely to also play a role in the era of increasing antibiotic resistance. Ongoing efforts and studies are working to implement these needs over the next 5 years, which will lead to an understanding that will increase the likelihood of a successful TB vaccine. PMID:26973073

  2. Ebola hemorrhagic Fever and the current state of vaccine development.

    Science.gov (United States)

    Hong, Joo Eun; Hong, Kee-Jong; Choi, Woo Young; Lee, Won-Ja; Choi, Yeon Hwa; Jeong, Chung-Hyeon; Cho, Kwang-Il

    2014-12-01

    Current Ebola virus outbreak in West Africa already reached the total number of 1,323 including 729 deaths by July 31st. the fatality is around 55% in the southeastern area of Guinea, Sierra Leone, Liberia, and Nigeria. The number of patients with Ebola Hemorrhagic Fever (EHF) was continuously increasing even though the any effective therapeutics or vaccines has not been developed yet. The Ebola virus in Guinea showed 98% homology with Zaire Ebola Virus. Study of the pathogenesis of Ebola virus infection and assess of the various candidates of vaccine have been tried for a long time, especially in United States and some European countries. Even though the attenuated live vaccine and DNA vaccine containing Ebola viral genes were tested and showed efficacy in chimpanzees, those candidates still need clinical tests requiring much longer time than the preclinical development to be approved for the practical treatment. It can be expected to eradicate Ebola virus by a safe and efficient vaccine development similar to the case of smallpox virus which was extinguished from the world by the variola vaccine. PMID:25562048

  3. Comparative Pathogenesis and Systems Biology for Biodefense Virus Vaccine Development

    Directory of Open Access Journals (Sweden)

    Gavin C. Bowick

    2010-01-01

    Full Text Available Developing vaccines to biothreat agents presents a number of challenges for discovery, preclinical development, and licensure. The need for high containment to work with live agents limits the amount and types of research that can be done using complete pathogens, and small markets reduce potential returns for industry. However, a number of tools, from comparative pathogenesis of viral strains at the molecular level to novel computational approaches, are being used to understand the basis of viral attenuation and characterize protective immune responses. As the amount of basic molecular knowledge grows, we will be able to take advantage of these tools not only to rationally attenuate virus strains for candidate vaccines, but also to assess immunogenicity and safety in silico. This review discusses how a basic understanding of pathogenesis, allied with systems biology and machine learning methods, can impact biodefense vaccinology.

  4. Postgenomics of Neisseria meningitidis for vaccines development.

    Science.gov (United States)

    Bernardini, Giulia; Braconi, Daniela; Martelli, Paola; Santucci, Annalisa

    2007-10-01

    Meningococcal disease is a global problem. Multivalent (A, C, Y, W135) conjugate vaccines have been developed and licensed; however, an effective vaccine against serogroup B has not yet become available. Outer membrane vesicle (OMV) vaccines have been used to disrupt serogroup B epidemics and outbreaks. Postgenomic technologies have been useful in aiding the discovery of new protein vaccine candidates. Moreover, proteomic technologies enable large-scale identification of membrane and surface-associated proteins, and provide suitable methods to characterize and standardize the antigen composition of OMV-based vaccines. PMID:17941821

  5. Extended safety and efficacy studies of a live attenuated double leucine and pantothenate auxotroph of Mycobacterium tuberculosis as a vaccine candidate

    OpenAIRE

    Sampson, Samantha L.; Mansfield, Keith G; Carville, Angela; Magee, D Mitchell; Quitugua, Teresa; Howerth, Elizabeth W.; Bloom, Barry R.; Hondalus, Mary K.

    2011-01-01

    We have previously described the development of a live, fully attenuated Mycobacterium tuberculosis (Mtb) vaccine candidate strain with two independent attenuating auxotrophic mutations in leucine and pantothenate biosynthesis. In the present work, those studies have been extended to include testing for protective efficacy in a long-term guinea pig survival model and safety testing in the highly tuberculosis susceptible Rhesus macaque. To model the safety of the ΔleuD ΔpanCD strain in HIV-inf...

  6. 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

    2016-02-01

    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. PMID:26588242

  7. Development of Mucosal Vaccines Based on Lactic Acid Bacteria

    Science.gov (United States)

    Bermúdez-Humarán, Luis G.; Innocentin, Silvia; Lefèvre, Francois; Chatel, Jean-Marc; Langella, Philippe

    Today, sufficient data are available to support the use of lactic acid bacteria (LAB), notably lactococci and lactobacilli, as delivery vehicles for the development of new mucosal vaccines. These non-pathogenic Gram-positive bacteria have been safely consumed by humans for centuries in fermented foods. They thus constitute an attractive alternative to the attenuated pathogens (most popular live vectors actually studied) which could recover their pathogenic potential and are thus not totally safe for use in humans. This chapter reviews the current research and advances in the use of LAB as live delivery vectors of proteins of interest for the development of new safe mucosal vaccines. The use of LAB as DNA vaccine vehicles to deliver DNA directly to antigen-presenting cells of the immune system is also discussed.

  8. Schistosoma mansoni polypeptides immunogenic in mice vaccinated with radiation-attenuated cercariae

    International Nuclear Information System (INIS)

    We compared the humoral immune response of mice protected against Schistosoma mansoni by vaccination with radiation-attenuated cercariae to that of patently infected mice, and we identified antigens that elicit a greater, or unique, immune response in the vaccinated mice. These comparisons were based upon radioimmunoprecipitations and immunodepletion of [35S]methionine-labeled schistosomular and adult worm polypeptides, followed by one- and two-dimensional polyacrylamide gel analyses. The humoral responses of patently infected mice and of mice vaccinated once were remarkably similar and were directed against schistosome glycoproteins ranging in molecular size from greater than 300 to less than 10 kDa. Exposing mice to a second vaccination resulted in a marked change in the immune response, to one predominantly directed toward high molecular size glycoproteins. Sequential immunodepletion techniques identified five schistosomular and seven adult worm antigens that showed a greater or unique immunogenicity in vaccinated mice as compared with patently infected mice. These adult worm antigens were purified by preparative sequential immunoaffinity chromatography and used to prepare a polyclonal antiserum, anti-irradiated vaccine. This antiserum bound to the surface of live newly transformed and lung-stage schistosomula, as assessed by immunofluorescence assays, and was reactive with a number of 125I-labeled schistosomular surface polypeptides, including a doublet of 150 kDa that was also recognized by sera of vaccinated mice but not by sera of patently infected mice

  9. Schistosoma mansoni polypeptides immunogenic in mice vaccinated with radiation-attenuated cercariae

    Energy Technology Data Exchange (ETDEWEB)

    Dalton, J.P.; Strand, M.

    1987-10-01

    We compared the humoral immune response of mice protected against Schistosoma mansoni by vaccination with radiation-attenuated cercariae to that of patently infected mice, and we identified antigens that elicit a greater, or unique, immune response in the vaccinated mice. These comparisons were based upon radioimmunoprecipitations and immunodepletion of (/sup 35/S)methionine-labeled schistosomular and adult worm polypeptides, followed by one- and two-dimensional polyacrylamide gel analyses. The humoral responses of patently infected mice and of mice vaccinated once were remarkably similar and were directed against schistosome glycoproteins ranging in molecular size from greater than 300 to less than 10 kDa. Exposing mice to a second vaccination resulted in a marked change in the immune response, to one predominantly directed toward high molecular size glycoproteins. Sequential immunodepletion techniques identified five schistosomular and seven adult worm antigens that showed a greater or unique immunogenicity in vaccinated mice as compared with patently infected mice. These adult worm antigens were purified by preparative sequential immunoaffinity chromatography and used to prepare a polyclonal antiserum, anti-irradiated vaccine. This antiserum bound to the surface of live newly transformed and lung-stage schistosomula, as assessed by immunofluorescence assays, and was reactive with a number of /sup 125/I-labeled schistosomular surface polypeptides, including a doublet of 150 kDa that was also recognized by sera of vaccinated mice but not by sera of patently infected mice.

  10. Status of vaccine research and development of vaccines for leishmaniasis.

    Science.gov (United States)

    Gillespie, Portia M; Beaumier, Coreen M; Strych, Ulrich; Hayward, Tara; Hotez, Peter J; Bottazzi, Maria Elena

    2016-06-01

    A number of leishmaniasis vaccine candidates are at various stages of pre-clinical and clinical development. Leishmaniasis is a vector-borne neglected tropical disease (NTD) caused by a protozoan parasite of the genus Leishmania and transmitted to humans by the bite of a sand fly. Visceral leishmaniasis (VL, kala-azar) is a high mortality NTD found mostly in South Asia and East Africa, while cutaneous leishmaniasis (CL) is a disfiguring NTD highly endemic in the Middle East, Central Asia, North Africa, and the Americas. Estimates attribute 50,000 annual deaths and 3.3 million disability-adjusted life years to leishmaniasis. There are only a few approved drug treatments, no prophylactic drug and no vaccine. Ideally, an effective vaccine against leishmaniasis will elicit long-lasting immunity and protect broadly against VL and CL. Vaccines such as Leish-F1, F2 and F3, developed at IDRI and designed based on selected Leishmania antigen epitopes, have been in clinical trials. Other groups, including the Sabin Vaccine Institute in collaboration with the National Institutes of Health are investigating recombinant Leishmania antigens in combination with selected sand fly salivary gland antigens in order to augment host immunity. To date, both VL and CL vaccines have been shown to be cost-effective in economic modeling studies. PMID:26973063

  11. A genetically attenuated malaria vaccine candidate based on P. falciparum b9/slarp gene-deficient sporozoites.

    Science.gov (United States)

    van Schaijk, Ben C L; Ploemen, Ivo H J; Annoura, Takeshi; Vos, Martijn W; Foquet, Lander; van Gemert, Geert-Jan; Chevalley-Maurel, Severine; van de Vegte-Bolmer, Marga; Sajid, Mohammed; Franetich, Jean-Francois; Lorthiois, Audrey; Leroux-Roels, Geert; Meuleman, Philip; Hermsen, Cornelius C; Mazier, Dominique; Hoffman, Stephen L; Janse, Chris J; Khan, Shahid M; Sauerwein, Robert W

    2014-01-01

    A highly efficacious pre-erythrocytic stage vaccine would be an important tool for the control and elimination of malaria but is currently unavailable. High-level protection in humans can be achieved by experimental immunization with Plasmodium falciparum sporozoites attenuated by radiation or under anti-malarial drug coverage. Immunization with genetically attenuated parasites (GAP) would be an attractive alternative approach. In this study, we present data on safety and protective efficacy using sporozoites with deletions of two genes, that is the newly identified b9 and slarp, which govern independent and critical processes for successful liver-stage development. In the rodent malaria model, PbΔb9ΔslarpGAP was completely attenuated showing no breakthrough infections while efficiently inducing high-level protection. The human PfΔb9ΔslarpGAP generated without drug resistance markers were infective to human hepatocytes in vitro and to humanized mice engrafted with human hepatocytes in vivo but completely aborted development after infection. These findings support the clinical development of a PfΔb9ΔslarpSPZ vaccine. PMID:25407681

  12. Gene Transcription Profile in Mice Vaccinated with Ultraviolet-attenuated Cercariae of Schistosoma japonicum Reveals Molecules Contributing to Elevated IFN-γLevels

    Institute of Scientific and Technical Information of China (English)

    Xiang ZHU; Feng LIU; Chuan SU; Guan-Ling WU; Zhao-Song ZHANG; Min-Jun JI; Hai-Wei WU; Yong WANG; Xiao-Ping CAI; Lei ZHANG; Shu-Ying HU; Lin-Lin FU

    2005-01-01

    Vaccination with ultraviolet-attenuated cercariae of Schistosoma japonicum induced protective immunity against challenge infection in experimental animal models. Our preliminary study on the transcription levels of IFN-γ and IL-4 in splenic CD4+ T cells revealed that attenuated cercariae elicited predominantly a Thl response in mice at the early stage, whereas normal cercariae stimulated primarily Th2dependent responses. Further analysis on the gene profile of the skin-draining lymph nodes demonstrated that the levels of IFN-γ were significantly higher in vaccinated mice than those in infected mice at day 4, 7 and 14 post-vaccination or post-infection. However, for IL-12 and IL-4, the potent inducers of Th l and Th2 responses, respectively, as well as IL-10, there were no differences over the course of the experiment between the infected and vaccinated mice. To explore the underlying factors that may potentially contribute to elevated IFN-γ in vaccinated mice, the mRNA profiles of the skin-draining lymph nodes at day 4 postexposure were compared using oligonucleotide microarrays. Within the 847 probe sets with increased signal values, we focused on chemokines, cytokines and relevant receptors, which were validated by semi-quantitative RT-PCR. A comprehensive understanding of the immune mechanisms of attenuated cercariae-induced protection may contribute to developing efficient vaccination strategies against S. japonicum, especially during the early stage of infection.

  13. Animal models of tuberculosis for vaccine development.

    Science.gov (United States)

    Gupta, U D; Katoch, V M

    2009-01-01

    Animal models for testing different vaccine candidates have been developed since a long time for studying tuberculosis. Mice, guinea pigs and rabbits are animals most frequently used. Each model has its own merits for studying human tuberculosis, and none completely mimics the human disease. Different animal models are being used depending upon the availability of the space, trained manpower as well as other resources. Efforts should continue to develop a vaccine which can replace/outperform the presently available vaccine BCG. PMID:19287053

  14. Development of Mycoplasma hyopneumoniae Recombinant Vaccines.

    Science.gov (United States)

    Marchioro, Silvana Beutinger; Simionatto, Simone; Dellagostin, Odir

    2016-01-01

    Mycoplasma hyopneumoniae is the etiological agent of swine enzootic pneumonia (EP), a disease that affects swine production worldwide. Vaccination is the most cost-effective strategy for the control and prevention of the disease. Research using genome-based approach has the potential to elucidate the biology and pathogenesis of M. hyopneumoniae and contribute to the development of more effective vaccines. Here, we describe the protocol for developing M. hyopneumoniae recombinant vaccines using reverse vaccinology approaches. PMID:27076288

  15. EXPERIMENTAL TRIALS OF LIVE ATTENUATED AND INACTIVATED STAPHYLOCOCCUS AUREUS VACCINES IN RABBITS

    Directory of Open Access Journals (Sweden)

    A. SHAKOOR, M. ATHAR, G. MUHAMMAD, S. U. RAHMAN1, A. A. BUTT2, I. HUSSAIN 2 AND R. AHMAD3

    2006-04-01

    Full Text Available This study was conducted as a preliminary step on the rabbits for comparative efficacy of different vaccines of Staphylococcus aureus. Typical alpha-beta Staph. aureus species from a clinically affected mastitic buffalo was isolated. After proper identification based on cultural and morphological characteristics and API-Staph Trac system, a selected Staph. aureus isolate was used to prepare four different mastitis vaccines (Bacterin, oil-adjuvanted, dextran sulphate adjuvanted and live attenuated after confirmation for pathogenicity and antigenicity, followed by its safety and sterility evaluation. Vaccines were tried in 25 rabbits divided into 5 equal groups. A separate vaccine was administered s/c @ 0.2 ml per animal and boosted at 15 days later. It was found that IHA antibody titers were higher (GMT 32-128 in live attenuated, dextran sulphate adjuvanted (GMT 32-128 and oil-adjuvanted (GMT 16-64 than the bacterin treated (GMT 16-32 group. All the vaccines showed an apparent immune response than the unvaccinated control group.

  16. A rapid immunization strategy with a live attenuated tetravalent dengue vaccine elicits protective neutralizing antibody responses in non-human primates

    Directory of Open Access Journals (Sweden)

    Yuping eAmbuel

    2014-06-01

    Full Text Available Dengue viruses (DENVs cause approximately 390 million cases of DENV infections annually and over 3 billion people worldwide are at risk of infection. No dengue vaccine is currently available nor is there an antiviral therapy for DENV infections. We have developed a tetravalent live-attenuated DENV vaccine (TDV that consists of a molecularly characterized attenuated DENV-2 strain (TDV-2 and three chimeric viruses containing the pre-membrane and envelope genes of DENV-1, -3 and -4 expressed in the context of the TDV-2 genome. To impact dengue vaccine delivery in endemic areas and immunize travelers, a simple and rapid immunization strategy (RIS is preferred. We investigated RIS consisting of two full vaccine doses being administered subcutaneously or intradermally on the initial vaccination visit (day 0 at two different anatomical locations with a needle-free disposable syringe jet injection (DSJI delivery devices (PharmaJet in non-human primates (NHP. This vaccination strategy resulted in efficient priming and induction of neutralizing antibody responses to all four DENV serotypes comparable to those elicited by the traditional prime and boost (two months later vaccination schedule. In addition, the vaccine induced CD4+ and CD8+ T cells producing IFN-γ, IL-2, and TNF-α, and targeting the DENV-2 NS1, NS3 and NS5 proteins. Moreover, vaccine-specific T cells were cross-reactive with the non-structural NS3 and NS5 proteins of DENV-4. When animals were challenged with DENV-2 they were protected with no detectable viremia, and exhibited sterilizing immunity (no increase of neutralizing titers post- challenge. RIS could decrease vaccination visits and provide quick immune response to all four DENV serotypes. This strategy could increase vaccination compliance and would be especially advantageous for travelers into endemic areas.

  17. Dengue human infection models to advance dengue vaccine development.

    Science.gov (United States)

    Larsen, Christian P; Whitehead, Stephen S; Durbin, Anna P

    2015-12-10

    Dengue viruses (DENV) currently infect approximately 400 million people each year causing millions to seek care and overwhelming the health care infrastructure in endemic areas. Vaccines to prevent dengue and therapeutics to treat dengue are not currently available. The efficacy of the most advanced candidate vaccine against symptomatic dengue in general and DENV-2 in particular was much lower than expected, despite the ability of the vaccine to induce neutralizing antibody against all four DENV serotypes. Because seroconversion to the DENV serotypes following vaccination was thought to be indicative of induced protection, these results have made it more difficult to assess which candidate vaccines should or should not be evaluated in large studies in endemic areas. A dengue human infection model (DHIM) could be extremely valuable to down-select candidate vaccines or therapeutics prior to engaging in efficacy trials in endemic areas. Two DHIM have been developed to assess the efficacy of live attenuated tetravalent (LATV) dengue vaccines. The first model, developed by the Laboratory of Infectious Diseases at the U. S. National Institutes of Health, utilizes a modified DENV-2 strain DEN2Δ30. This virus was derived from the DENV-2 Tonga/74 that caused only very mild clinical infection during the outbreak from which it was recovered. DEN2Δ30 induced viremia in 100%, rash in 80%, and neutropenia in 27% of the 30 subjects to whom it was given. The Walter Reed Army Institute of Research (WRAIR) is developing a DHIM the goal of which is to identify DENV that cause symptomatic dengue fever. WRAIR has evaluated seven viruses and has identified two that meet dengue fever criteria. Both of these models may be very useful in the evaluation and down-selection of candidate dengue vaccines and therapeutics. PMID:26424605

  18. Recent advances in the development of vaccines against ricin.

    Science.gov (United States)

    Brey, Robert N; Mantis, Nicholas J; Pincus, Seth H; Vitetta, Ellen S; Smith, Leonard A; Roy, Chad J

    2016-05-01

    Several promising subunit vaccines against ricin toxin (RT) have been developed during the last decade and are now being tested for safety and immunogenicity in humans and for efficacy in nonhuman primates. The incentive to develop a preventive vaccine as a countermeasure against RT use as a bioweapon is based on the high toxicity of RT after aerosol exposure, its environmental stability, abundance, and ease of purification. RT is the second most lethal biological toxin and is considered a "universal toxin" because it can kill all eukaryotic cells through binding to ubiquitous cell surface galactosyl residues. RT has two subunits conjoined by a single disulfide linkage: RTB, which binds galactosyl residues and RTA which enzymatically inactivates ribosomes intracellularly by cleavage ribosomal RNA. Attenuation of toxicity by elimination of the active site or introduction of other structural mutations of RTA has generated two similar clinical subunit vaccine candidates which induce antibodies in both humans and nonhuman primates. In rhesus macaques, inhaled RT causes rapid lung necrosis and fibrosis followed by death. After parenteral vaccination with RTA vaccine, macaques can be protected against aerosol RT exposure, suggesting that circulating antibodies can protect lung mucosa. Vaccination induces RT-neutralizing antibodies, the most likely correlate of protection. Macaques responded to conformational determinants in an RTA vaccine formulation, indicating preservation of RTA structure during initial manufacture. Comparative mapping studies have also demonstrated that macaques and humans recognize the same epitopes, significant in the study of macaques as a model during development of vaccines which cannot be tested for efficacy in humans. PMID:26810367

  19. Inactivated or Live-Attenuated Bivalent Vaccines That Confer Protection against Rabies and Ebola Viruses ▿

    Science.gov (United States)

    Blaney, Joseph E.; Wirblich, Christoph; Papaneri, Amy B.; Johnson, Reed F.; Myers, Carey J.; Juelich, Terry L.; Holbrook, Michael R.; Freiberg, Alexander N.; Bernbaum, John G.; Jahrling, Peter B.; Paragas, Jason; Schnell, Matthias J.

    2011-01-01

    The search for a safe and efficacious vaccine for Ebola virus continues, as no current vaccine candidate is nearing licensure. We have developed (i) replication-competent, (ii) replication-deficient, and (iii) chemically inactivated rabies virus (RABV) vaccines expressing Zaire Ebola virus (ZEBOV) glycoprotein (GP) by a reverse genetics system based on the SAD B19 RABV wildlife vaccine. ZEBOV GP is efficiently expressed by these vaccine candidates and is incorporated into virions. The vaccine candidates were avirulent after inoculation of adult mice, and viruses with a deletion in the RABV glycoprotein had greatly reduced neurovirulence after intracerebral inoculation in suckling mice. Immunization with live or inactivated RABV vaccines expressing ZEBOV GP induced humoral immunity against each virus and conferred protection from both lethal RABV and EBOV challenge in mice. The bivalent RABV/ZEBOV vaccines described here have several distinct advantages that may speed the development of inactivated vaccines for use in humans and potentially live or inactivated vaccines for use in nonhuman primates at risk of EBOV infection in endemic areas. PMID:21849459

  20. Inactivated or live-attenuated bivalent vaccines that confer protection against rabies and Ebola viruses.

    Science.gov (United States)

    Blaney, Joseph E; Wirblich, Christoph; Papaneri, Amy B; Johnson, Reed F; Myers, Carey J; Juelich, Terry L; Holbrook, Michael R; Freiberg, Alexander N; Bernbaum, John G; Jahrling, Peter B; Paragas, Jason; Schnell, Matthias J

    2011-10-01

    The search for a safe and efficacious vaccine for Ebola virus continues, as no current vaccine candidate is nearing licensure. We have developed (i) replication-competent, (ii) replication-deficient, and (iii) chemically inactivated rabies virus (RABV) vaccines expressing Zaire Ebola virus (ZEBOV) glycoprotein (GP) by a reverse genetics system based on the SAD B19 RABV wildlife vaccine. ZEBOV GP is efficiently expressed by these vaccine candidates and is incorporated into virions. The vaccine candidates were avirulent after inoculation of adult mice, and viruses with a deletion in the RABV glycoprotein had greatly reduced neurovirulence after intracerebral inoculation in suckling mice. Immunization with live or inactivated RABV vaccines expressing ZEBOV GP induced humoral immunity against each virus and conferred protection from both lethal RABV and EBOV challenge in mice. The bivalent RABV/ZEBOV vaccines described here have several distinct advantages that may speed the development of inactivated vaccines for use in humans and potentially live or inactivated vaccines for use in nonhuman primates at risk of EBOV infection in endemic areas. PMID:21849459

  1. Live Attenuated Influenza Vaccine Provides Superior Protection from Heterologous Infection in Pigs with Maternal Antibodies without Inducing Vaccine-Associated Enhanced Respiratory Disease

    OpenAIRE

    Vincent, Amy L.; Ma, Wenjun; Lager, Kelly M.; Richt, Jürgen A.; Janke, Bruce H.; Sandbulte, Matthew R.; Gauger, Philip C.; Loving, Crystal L.; Webby, Richard J; García-Sastre, Adolfo

    2012-01-01

    Control of swine influenza A virus (IAV) in the United States is hindered because inactivated vaccines do not provide robust cross-protection against the multiple antigenic variants cocirculating in the field. Vaccine efficacy can be limited further for vaccines administered to young pigs that possess maternally derived immunity. We previously demonstrated that a recombinant A/sw/Texas/4199-2/1998 (TX98) (H3N2) virus expressing a truncated NS1 protein is attenuated in swine and has potential ...

  2. Replication and transmission of live attenuated infectious laryngotracheitis virus (ILTV) vaccines.

    Science.gov (United States)

    Rodríguez-Avila, Andrés; Oldoni, Ivomar; Riblet, Sylva; García, Maricarmen

    2007-12-01

    The aim of this study was to evaluate the replication of live attenuated infectious laryngotracheitis virus vaccines in selected tissues and their ability to transmit to contact-exposed birds. Four-week-old specific-pathogen-free chickens were eye drop-inoculated with tissue culture origin (TCO) and chicken embryo origin (CEO) vaccines. Contact-exposed chickens were housed in direct contact with eye drop-inoculated chickens from the first day postinoculation. Virus isolation and real-time polymerase chain reaction were used to detect the presence of live virus and viral DNA, respectively, in the trachea, trigeminal ganglia, eye conjunctiva, cecal tonsils, and cloaca from eye drop-inoculated and contact-exposed birds at days 2, 4, 5 to 10, 14, 18, 21, 24, and 28 postinoculation. No differences were observed in the ability of the TCO and CEO vaccines to replicate in the examined tissues. Both vaccines presented a localized replication in the eye conjunctiva and the trachea. Both vaccines were capable of transmitting to contact-exposed birds, attaining peaks of viral DNA as elevated as those observed in inoculated birds. The CEO vaccine replicated faster and reached higher viral genome copy number than the TCO vaccine in the conjunctiva and trachea of eye drop-inoculated and contact-exposed birds. The viral DNA from both vaccines migrated to the trigeminal ganglia during early stages of infection. Although the CEO and TCO vaccines were not recovered from the cecal tonsils and the cloaca, low levels of viral DNA were detected at these sites during the peak of viral replication in the upper respiratory tract. PMID:18251401

  3. Comparative sequence analysis of the P-, M- and L-coding region of the measles virus CAM-70 live attenuated vaccine strain

    Directory of Open Access Journals (Sweden)

    P.R. Santos

    2003-11-01

    Full Text Available Measles virus is a highly contagious agent which causes a major health problem in developing countries. The viral genomic RNA is single-stranded, nonsegmented and of negative polarity. Many live attenuated vaccines for measles virus have been developed using either the prototype Edmonston strain or other locally isolated measles strains. Despite the diverse geographic origins of the vaccine viruses and the different attenuation methods used, there was remarkable sequence similarity of H, F and N genes among all vaccine strains. CAM-70 is a Japanese measles attenuated vaccine strain widely used in Brazilian children and produced by Bio-Manguinhos since 1982. Previous studies have characterized this vaccine biologically and genomically. Nevertheless, only the F, H and N genes have been sequenced. In the present study we have sequenced the remaining P, M and L genes (approximately 1.6, 1.4 and 6.5 kb, respectively to complete the genomic characterization of CAM-70 and to assess the extent of genetic relationship between CAM-70 and other current vaccines. These genes were amplified using long-range or standard RT-PCR techniques, and the cDNA was cloned and automatically sequenced using the dideoxy chain-termination method. The sequence analysis comparing previously sequenced genotype A strains with the CAM-70 Bio-Manguinhos strain showed a low divergence among them. However, the CAM-70 strains (CAM-70 Bio-Manguinhos and a recently sequenced CAM-70 submaster seed strain were assigned to a specific group by phylogenetic analysis using the neighbor-joining method. Information about our product at the genomic level is important for monitoring vaccination campaigns and for future studies of measles virus attenuation.

  4. Development of a new vaccine for the prevention of Lassa fever.

    Directory of Open Access Journals (Sweden)

    Thomas W Geisbert

    2005-06-01

    Full Text Available BACKGROUND: Recent importation of Lassa fever into Germany, the Netherlands, the United Kingdom, and the United States by travelers on commercial airlines from Africa underscores the public health challenge of emerging viruses. Currently, there are no licensed vaccines for Lassa fever, and no experimental vaccine has completely protected nonhuman primates against a lethal challenge. METHODS AND FINDINGS: We developed a replication-competent vaccine against Lassa virus based on attenuated recombinant vesicular stomatitis virus vectors expressing the Lassa viral glycoprotein. A single intramuscular vaccination of the Lassa vaccine elicited a protective immune response in nonhuman primates against a lethal Lassa virus challenge. Vaccine shedding was not detected in the monkeys, and none of the animals developed fever or other symptoms of illness associated with vaccination. The Lassa vaccine induced strong humoral and cellular immune responses in the four vaccinated and challenged monkeys. Despite a transient Lassa viremia in vaccinated animals 7 d after challenge, the vaccinated animals showed no evidence of clinical disease. In contrast, the two control animals developed severe symptoms including rashes, facial edema, and elevated liver enzymes, and ultimately succumbed to the Lassa infection. CONCLUSION: Our data suggest that the Lassa vaccine candidate based on recombinant vesicular stomatitis virus is safe and highly efficacious in a relevant animal model that faithfully reproduces human disease.

  5. Development of a New Vaccine for the Prevention of Lassa Fever

    Science.gov (United States)

    2005-01-01

    Background Recent importation of Lassa fever into Germany, the Netherlands, the United Kingdom, and the United States by travelers on commercial airlines from Africa underscores the public health challenge of emerging viruses. Currently, there are no licensed vaccines for Lassa fever, and no experimental vaccine has completely protected nonhuman primates against a lethal challenge. Methods and Findings We developed a replication-competent vaccine against Lassa virus based on attenuated recombinant vesicular stomatitis virus vectors expressing the Lassa viral glycoprotein. A single intramuscular vaccination of the Lassa vaccine elicited a protective immune response in nonhuman primates against a lethal Lassa virus challenge. Vaccine shedding was not detected in the monkeys, and none of the animals developed fever or other symptoms of illness associated with vaccination. The Lassa vaccine induced strong humoral and cellular immune responses in the four vaccinated and challenged monkeys. Despite a transient Lassa viremia in vaccinated animals 7 d after challenge, the vaccinated animals showed no evidence of clinical disease. In contrast, the two control animals developed severe symptoms including rashes, facial edema, and elevated liver enzymes, and ultimately succumbed to the Lassa infection. Conclusion Our data suggest that the Lassa vaccine candidate based on recombinant vesicular stomatitis virus is safe and highly efficacious in a relevant animal model that faithfully reproduces human disease. PMID:15971954

  6. Development of Novel Vaccines against Enterovirus-71

    Directory of Open Access Journals (Sweden)

    Pinn Tsin Isabel Yee

    2015-12-01

    Full Text Available The hand, foot and mouth disease is caused by a group of Enteroviruses such as Enterovirus 71 (EV-A71 and Coxsackievirus CV-A5, CV-A8, and CV-A16. Mild symptoms of EV-A71 infection in children range from high fever, vomiting, rashes and ulcers in mouth but can produce more severe symptoms such as brainstem and cerebellar encephalitis, leading up to cardiopulmonary failure and death. The lack of vaccines and antiviral drugs against EV-A71 highlights the urgency of developing preventive and treatment agents against EV-A71 to prevent further fatalities. Research groups have developed experimental inactivated vaccines, recombinant Viral Protein 1 (VP1 vaccine and virus-like particles (VLPs. The inactivated EV-A71 vaccine is considered the safest viral vaccine, as there will be no reversion to the infectious wild type strain. The recombinant VP1 vaccine is a cost-effective immunogen, while VLPs contain an arrangement of epitopes that can elicit neutralizing antibodies against the virus. As each type of vaccine has its advantages and disadvantages, increased studies are required in the development of such vaccines, whereby high efficacy, long-lasting immunity, minimal risk to those vaccinated, safe and easy production, low cost, dispensing the need for refrigeration and convenient delivery are the major goals in their design.

  7. Development of Novel Vaccines against Enterovirus-71.

    Science.gov (United States)

    Yee, Pinn Tsin Isabel; Poh, Chit Laa

    2016-01-01

    The hand, foot and mouth disease is caused by a group of Enteroviruses such as Enterovirus 71 (EV-A71) and Coxsackievirus CV-A5, CV-A8, and CV-A16. Mild symptoms of EV-A71 infection in children range from high fever, vomiting, rashes and ulcers in mouth but can produce more severe symptoms such as brainstem and cerebellar encephalitis, leading up to cardiopulmonary failure and death. The lack of vaccines and antiviral drugs against EV-A71 highlights the urgency of developing preventive and treatment agents against EV-A71 to prevent further fatalities. Research groups have developed experimental inactivated vaccines, recombinant Viral Protein 1 (VP1) vaccine and virus-like particles (VLPs). The inactivated EV-A71 vaccine is considered the safest viral vaccine, as there will be no reversion to the infectious wild type strain. The recombinant VP1 vaccine is a cost-effective immunogen, while VLPs contain an arrangement of epitopes that can elicit neutralizing antibodies against the virus. As each type of vaccine has its advantages and disadvantages, increased studies are required in the development of such vaccines, whereby high efficacy, long-lasting immunity, minimal risk to those vaccinated, safe and easy production, low cost, dispensing the need for refrigeration and convenient delivery are the major goals in their design. PMID:26729152

  8. Effect of ionizing radiation on postvaccination immunity of laboratory animals vaccinated with ''Brucellovac'' attenuated vaccine

    Energy Technology Data Exchange (ETDEWEB)

    Bilecki, S.; Szpakowska, M.; Gabrys, A.; Krzeszowska, J. (Wojskowy Inst. Higieny i Epidemiologii, Warsaw (Poland))

    1979-01-01

    Rabbits received a single whole-body dose of gamma rays (300 or 600 R from /sup 60/Co), and were vaccinated with Brucellovac vaccine at various times before, after, and on day of the irradiation. The dose of 300 R induced only leukopenia, while the dose of 600 R - clinical and autopsy signs of radiation disease, erythropenia, leukopenia, lymphopenia, and an increase in neutral granulocyte count. Mortality after 600 R was 60%. In groups of rabbits vaccinated and irradiated with 300 R, geometric mean titers of serological tests were always higher than in animals vaccinated and not irradiated. Animals vaccinated and given 600 R developed lower titers than controls of vaccination was performed after, or on day of the irradiation; the titers were same as in controls if vaccination was performed prior to irradiation. The irradiation had no effect on incomplete antibody formation and on immunoglobulin classes, as well as on the results of opsono-phagocytic test which were negative in all groups and doubtful in single cases.

  9. Relaxation of Purifying Selection on the SAD Lineage of Live Attenuated Oral Vaccines for Rabies Virus

    OpenAIRE

    Hughes, Austin L.

    2009-01-01

    Analysis of patterns of nucleotide sequence diversity in wild-type rabies virus (RABV) genomes and in the SAD live attenuated oral vaccine lineage was used to test for the relaxation of purifying selection in the latter and provide evidence regarding the genomic regions where such relaxation of selection occurs. The wild-type sequences showed evidence of strong past and ongoing purifying selection both on non-synonymous sites in coding regions and on non-coding regions, particularly the start...

  10. Viral Nucleic Acids in Live-Attenuated Vaccines: Detection of Minority Variants and an Adventitious Virus▿ †

    OpenAIRE

    Victoria, Joseph G.; Wang, Chunlin; Jones, Morris S.; Jaing, Crystal; McLoughlin, Kevin; Gardner, Shea; Delwart, Eric L.

    2010-01-01

    Metagenomics and a panmicrobial microarray were used to examine eight live-attenuated viral vaccines. Viral nucleic acids in trivalent oral poliovirus (OPV), rubella, measles, yellow fever, varicella-zoster, multivalent measles/mumps/rubella, and two rotavirus live vaccines were partially purified, randomly amplified, and pyrosequenced. Over half a million sequence reads were generated covering from 20 to 99% of the attenuated viral genomes at depths reaching up to 8,000 reads per nucleotides...

  11. Recent progress in dengue vaccine development

    Institute of Scientific and Technical Information of China (English)

    Jianchun; Wei; Hui; Chen; Jing; An

    2014-01-01

    Dengue virus(DENV) has four distinct serotypes. DENV infection can result in classic dengue fever and life-threatening dengue hemorrhagic fever/dengue shock syndrome. In recent decades, DENV infection has become an important public health concern in epidemic-prone areas. Vaccination is the most effective measure to prevent and control viral infections. However, several challenges impede the development of effective DENV vaccines, such as the lack of suitable animal models and the antibody-dependent enhancement phenomenon. Although no licensed DENV vaccine is available, significant progress has been made. This review summarizes candidate DENV vaccines from recent investigations.

  12. Why the radiation-attenuated cercarial immunization studies failed to guide the road for an effective schistosomiasis vaccine: A review

    Directory of Open Access Journals (Sweden)

    Rashika El Ridi

    2015-05-01

    Full Text Available Schistosomiasis is a debilitating parasitic disease caused by platyhelminthes of the genus Schistosoma, notably Schistosoma mansoni, Schistosoma haematobium, and Schistosoma japonicum. Pioneer researchers used radiation-attenuated (RA schistosome larvae to immunize laboratory rodent and non-human primate hosts. Significant and reproducible reduction in challenge worm burden varying from 30% to 90% was achieved, providing a sound proof that vaccination against this infection is feasible. Extensive histopathological, tissue mincing and incubation, autoradiographic tracking, parasitological, and immunological studies led to defining conditions and settings for achieving optimal protection and delineating the resistance underlying mechanisms. The present review aims to summarize these findings and draw the lessons that should have guided the development of an effective schistosomiasis vaccine.

  13. Why the radiation-attenuated cercarial immunization studies failed to guide the road for an effective schistosomiasis vaccine: A review.

    Science.gov (United States)

    El Ridi, Rashika; Tallima, Hatem

    2015-05-01

    Schistosomiasis is a debilitating parasitic disease caused by platyhelminthes of the genus Schistosoma, notably Schistosoma mansoni, Schistosoma haematobium, and Schistosoma japonicum. Pioneer researchers used radiation-attenuated (RA) schistosome larvae to immunize laboratory rodent and non-human primate hosts. Significant and reproducible reduction in challenge worm burden varying from 30% to 90% was achieved, providing a sound proof that vaccination against this infection is feasible. Extensive histopathological, tissue mincing and incubation, autoradiographic tracking, parasitological, and immunological studies led to defining conditions and settings for achieving optimal protection and delineating the resistance underlying mechanisms. The present review aims to summarize these findings and draw the lessons that should have guided the development of an effective schistosomiasis vaccine. PMID:26257924

  14. Correlates of Immunity to Influenza as Determined by Challenge of Children with Live, Attenuated Influenza Vaccine

    Science.gov (United States)

    Wright, Peter F.; Hoen, Anne G.; Ilyushina, Natalia A.; Brown, Eric P.; Ackerman, Margaret E.; Wieland-Alter, Wendy; Connor, Ruth I.; Jegaskanda, Sinthujan; Rosenberg-Hasson, Yael; Haynes, Brenda C.; Luke, Catherine J.; Subbarao, Kanta; Treanor, John J.

    2016-01-01

    Background. The efficacy of live, attenuated live attenuated influenza vaccine(LAIV) and inactivated influenza vaccine(IIV) is poorly explained by either single or composite immune responses to vaccination. Protective biomarkers were therefore studied in response to LAIV or IIV followed by LAIV challenge in children. Methods. Serum and mucosal responses to LAIV or IIV were analyzed using immunologic assays to assess both quantitative and functional responses. Cytokines and chemokines were measured in nasal washes collected before vaccination, on days 2, 4, and 7 after initial LAIV, and again after LAIV challenge using a 63-multiplex Luminex panel. Results. Patterns of immunity induced by LAIV and IIV were significantly different. Serum responses induced by IIV, including hemagglutination inhibition, did not correlate with detection or quantitation of LAIV on subsequent challenge. Modalities that induced sterilizing immunity seen after LAIV challenge could not be defined by any measurements of mucosal or serum antibodies induced by the initial LAIV immunization. No single cytokine or chemokine was predictive of protection. Conclusions. The mechanism of protective immunity observed after LAIV could not be defined, and traditional measurements of immunity to IIV did not correlate with protection against an LAIV challenge.

  15. Identification of the pXO1 plasmid in attenuated Bacillus anthracis vaccine strains.

    Science.gov (United States)

    Liang, Xudong; Zhang, Huijuan; Zhang, Enmin; Wei, Jianchun; Li, Wei; Wang, Bingxiang; Dong, Shulin; Zhu, Jin

    2016-07-01

    Anthrax toxins and capsule are the major virulence factors of Bacillus anthracis. They are encoded by genes located on the plasmids pXO1 and pXO2, respectively. The vaccine strain Pasteur II was produced from high temperature subcultures of B. anthracis, which resulted in virulence attenuation through the loss of the plasmid pXO1. However, it is unclear whether the high temperature culture completely abolishes the plasmid DNA or affects the replication of the plasmid pXO1. In this study, we tested 3 B. anthracis vaccine strains, including Pasteur II from France, Qiankefusiji II from Russia, and Rentian II from Japan, which were all generated from subcultures at high temperatures. Surprisingly, we detected the presence of pXO1 plasmid DNA using overlap PCR in all these vaccine strains. DNA sequencing analysis of overlap PCR products further confirmed the presence of pXO1. Moreover, the expression of the protective antigen (PA) encoded on pXO1 was determined by using SDS-PAGE and western blotting. In addition, we mimicked Pasteur's method and exposed the A16R vaccine strain, which lacks the pXO2 plasmid, to high temperature, and identified the pXO1 plasmid in the subcultures at high temperatures. This indicated that the high temperature treatment at 42.5°C was unable to eliminate pXO1 plasmid DNA from B. anthracis. Our results suggest that the attenuation of the Pasteur II vaccine strain is likely due to the impact of high temperature stress on plasmid replication, which in turn limits the copy number of pXO1. Our data provide new insights into the mechanisms of the remaining immunogenicity and toxicity of the vaccine strains. PMID:27029580

  16. Transcriptional profiles of multiple genes in the anterior kidney of channel catfish vaccinated with an attenuated Aeromonas hydrophila

    Science.gov (United States)

    A total of 22 uniquely expressed sequence tags (ESTs) were identified from channel catfish anterior kidney subtractive cDNA library at 12h post vaccination with an attenuated A. hydrophila (AL09-71 N+R). Of the 22 ESTs, six were confirmed to be significantly (P<0.05) induced by the vaccination. Of 8...

  17. Membrane and envelope virus proteins co-expressed as lysosome associated membrane protein (LAMP) fused antigens: a potential tool to develop DNA vaccines against flaviviruses

    OpenAIRE

    Rafael Dhalia; Milton Maciel Jr.; Fábia S.P. Cruz; Isabelle F.T. Viana; Mariana L. Palma; Thomas August; Ernesto T.A. Marques Jr.

    2009-01-01

    Vaccination is the most practical and cost-effective strategy to prevent the majority of the flavivirus infection to which there is an available vaccine. However, vaccines based on attenuated virus can potentially promote collateral side effects and even rare fatal reactions. Given this scenario, the developent of alternative vaccination strategies such as DNA-based vaccines encoding specific flavivirus sequences are being considered. Endogenous cytoplasmic antigens, characteristically plasmi...

  18. Generation of an infectious clone of HuN4-F112, an attenuated live vaccine strain of porcine reproductive and respiratory syndrome virus

    Directory of Open Access Journals (Sweden)

    Zhang Shanrui

    2011-08-01

    Full Text Available Abstract Background Nowadays, PRRS has become one of the most economically important infectious diseases of pig worldwide. To better characterize and understand the molecular basis of PRRSV virulence determinants, it would be important to develop the infectious cDNA clones. In this regard, HuN4-F112, a live-attenuated North-American-type PRRSV vaccine strain, could serve as an excellent model. Results In the study, genomic sequence of HuN4-F112, an attenuated vaccine virus derived from the highly pathogenic porcine reproductive and respiratory syndrome virus (PRRSV HuN4 strain, was determined and its full-length cDNA was cloned. Capped RNA was transcribed in vitro from the cDNA clone and transfected into BHK-21 cells. The supernatant from transfected monolayers were serially passaged in Marc-145 cells. The rescued virus exhibited a similar growth pattern to its parental virus in Marc-145 cells with peak titers at 48 h post-infection. Conclusion In conclusion, we rescued virus from an infectious cDNA clone of attenuated vaccine. It is possible in the future that a new attenuated PRRSV vaccine with broader specificity and good immunogenicity can be designed in vitro via an infectious cDNA clone platform coupled with validated information on virulence determinants.

  19. Nonclinical Development of BCG Replacement Vaccine Candidates.

    Science.gov (United States)

    Velmurugan, Kamalakannan; Grode, Leander; Chang, Rosemary; Fitzpatrick, Megan; Laddy, Dominick; Hokey, David; Derrick, Steven; Morris, Sheldon; McCown, David; Kidd, Reginald; Gengenbacher, Martin; Eisele, Bernd; Kaufmann, Stefan H E; Fulkerson, John; Brennan, Michael J

    2013-01-01

    The failure of current Mycobacterium bovis bacille Calmette-Guérin (BCG) vaccines, given to neonates to protect against adult tuberculosis and the risk of using these live vaccines in HIV-infected infants, has emphasized the need for generating new, more efficacious and safer replacement vaccines. With the availability of genetic techniques for constructing recombinant BCG (rBCG) strains containing well-defined gene deletions or insertions, new vaccine candidates are under evaluation at both the preclinical and clinical stages of development. Since most BCG vaccines in use today were evaluated in clinical trials decades ago and are produced by outdated processes, the development of new BCG vaccines offers a number of advantages that include a modern well-defined manufacturing process along with state-of-the-art evaluation of safety and efficacy in target populations. We provide a description of the preclinical development of two novel rBCGs, VPM1002 that was constructed by adding a modified hly gene coding for the protein listeriolysin O (LLO) from Listeria monocytogenes and AERAS-422, which carries a modified pfoA gene coding for the protein perfringolysin O (PFO) from Clostridium perfringens, and three genes from Mycobacterium tuberculosis. Novel approaches like these should be helpful in generating stable and effective rBCG vaccine candidates that can be better characterized than traditional BCG vaccines. PMID:26343962

  20. Nonclinical Development of BCG Replacement Vaccine Candidates

    Directory of Open Access Journals (Sweden)

    Bernd Eisele

    2013-04-01

    Full Text Available The failure of current Mycobacterium bovis bacille Calmette–Guérin (BCG vaccines, given to neonates to protect against adult tuberculosis and the risk of using these live vaccines in HIV-infected infants, has emphasized the need for generating new, more efficacious and safer replacement vaccines. With the availability of genetic techniques for constructing recombinant BCG (rBCG strains containing well-defined gene deletions or insertions, new vaccine candidates are under evaluation at both the preclinical and clinical stages of development. Since most BCG vaccines in use today were evaluated in clinical trials decades ago and are produced by outdated processes, the development of new BCG vaccines offers a number of advantages that include a modern well-defined manufacturing process along with state-of-the-art evaluation of safety and efficacy in target populations. We provide a description of the preclinical development of two novel rBCGs, VPM1002 that was constructed by adding a modified hly gene coding for the protein listeriolysin O (LLO from Listeria monocytogenes and AERAS-422, which carries a modified pfoA gene coding for the protein perfringolysin O (PFO from Clostridium perfringens, and three genes from Mycobacterium tuberculosis. Novel approaches like these should be helpful in generating stable and effective rBCG vaccine candidates that can be better characterized than traditional BCG vaccines.

  1. Progress and controversies in developing cancer vaccines

    Directory of Open Access Journals (Sweden)

    Speiser Daniel E

    2005-04-01

    Full Text Available Abstract Immunotherapy has become a standard approach for cancer management, through the use of cytokines (eg: interleukin-2 and monoclonal antibodies. Cancer vaccines hold promise as another form of immunotherapy, and there has been substantial progress in identifying shared antigens recognized by T cells, in developing vaccine approaches that induce antigen-specific T cell responses in cancer patients, and in developing new technology for monitoring immune responses in various human tissue compartments. Dramatic clinical regressions of human solid tumors have occurred with some cancer vaccines, but the rate of those responses remains low. This article is part of a 2-part point:counterpoint series on peptide vaccines and adoptive therapy approaches for cancer. The current status of cancer vaccination, and associated challenges, are discussed. Emphasis is placed on the need to increase our knowledge of cancer immunobiology, as well as to improve monitoring of cellular immune function after vaccination. Progress in both areas will facilitate development of effective cancer vaccines, as well as of adoptive therapy. Effective cancer vaccines promise to be useful for treatment and prevention of cancer at low cost and with low morbidity.

  2. Immunity to schistosomiasis mansoni in guinea-pigs vaccinated with radiation-attenuated cercariae

    International Nuclear Information System (INIS)

    The anti-schistosomular humoral responses of guinea-pigs vaccinated with radiation-attenuated cercariae of Schistosoma mansoni have been investigated in vitro. The sera of vaccinated animals contain schistosomulicidal complement-fixing antibodies which peak in titre at week 5 after vaccination and predominantly consist of IgG2 and IgM antibodies. The ability of the serum to arm macrophages from normal animals to bind to schistosomula, also peaks in titre at week 5 and is associated with IgG2 antibodies. Basophils from normal animals can be sensitized in vitro by vaccine serum to degranulate in the presence of schistosomular antigens. This anaphylactic antibody activity is associated with IgG1 but not IgE antibodies, and peaks in titre at week 10. Three antigens (14 kD, 20 kD and 43 kD) are specifically and transiently detected by vaccine serum on Western blots of schistosomular proteins; these antigens are first discernible at week 4, but were virtually undetectable at week 12. (author)

  3. Relaxation of purifying selection on the SAD lineage of live attenuated oral vaccines for rabies virus.

    Science.gov (United States)

    Hughes, Austin L

    2009-09-01

    Analysis of patterns of nucleotide sequence diversity in wild-type rabies virus (RABV) genomes and in the SAD live attenuated oral vaccine lineage was used to test for the relaxation of purifying selection in the latter and provide evidence regarding the genomic regions where such relaxation of selection occurs. The wild-type sequences showed evidence of strong past and ongoing purifying selection both on nonsynonymous sites in coding regions and on non-coding regions, particularly the start, end and 5' UTR regions. SAD vaccine sequences showed a relaxation of purifying selection at nonsynonymous sites in coding regions, resulting a substantial number of amino acid sequence polymorphisms at sites that were invariant in the wild-type sequences. Moreover, SAD vaccine sequences showed high levels of mutation accumulation in the non-coding regions that were most conserved in the wild-type sequences. Understanding the biological effects of the unique mutations accumulated in the vaccine lineage is important because of their potential effects on antigenicity and effectiveness of the vaccine. PMID:19409512

  4. Construction of a recombinant attenuated Salmonella typhimurium DNA vaccine carrying Helicobacter pylori hpaA

    Institute of Scientific and Technical Information of China (English)

    Can Xu; Zhao-Shen Li; Yi-Qi Du; Zhen-Xing Tu; Yan-Fang Gong; Jing Jin; Hong-Yu Wu; Guo-Ming Xu

    2005-01-01

    AIM: To construct a recombinant attenuated Salmonella typhimurium DNA vaccine carrying Helicobacter pylori hpaA gene and to detect its immunogenicity.METHODS: Genomic DNA of the standard H pylori strain 17 874 was isolated as the template, hpaA gene fragment was amplified by polymerase chain reaction (PCR) and cloned into pUCmT vector. DNA sequence of the amplified hpaA gene was assayed, then cloned into the eukaryotic expression vector pIRES through enzyme digestion and ligation reactions. The recombinant plasmid was used to transform competent Escherichia coliDH5α, and the positive clones were screened by PCR and restriction enzyme digestion. Then, the recombinant pIRES-hpaA was used to transform LB5000 and the recombinant plasmid isolated from LB5000 was finally used to transform SL7207. After that, the recombinant strain was grown in vitrorepeatedly. In order to iclentify the immunogenicity of the vaccinein vitro, the recombinant pIRES-hpaA was transfected to COS-7 cells using LipofectamineTM2000, the immunogenicity of expressed HpaA protein was detected with SDS-PAGE and Western blot.RESULTS: The 750-base pair hpaA gene fragment was amplified from the genomic DNA and was consistent with the sequence of H pylori hpaA by sequence analysis. It was confirmed by PCR and restriction enzyme digestion that H pylori hpaA gene was inserted into the eukaryotic expression vector pIRES and a stable recombinant live attenuated Salmonella typhimurium DNA vaccine carrying H pylori hpaA gene was successfully constructed and the specific strip of HpaA expressed by pIRES-hpaA was detected through Western blot.CONCLUSION: The recombinant attenuated Salmonella typhimurium DNA vaccine strain expressing HpaA protein with immunogenicity can be constructed and it may be helpful for further investigating the immune action of DNA vaccine in vivo.

  5. From empiricism to rational design: a personal perspective of the evolution of vaccine development.

    Science.gov (United States)

    De Gregorio, Ennio; Rappuoli, Rino

    2014-07-01

    Vaccination, which is the most effective medical intervention that has ever been introduced, originated from the observation that individuals who survived a plague or smallpox would not get the disease twice. To mimic the protective effects of natural infection, Jenner - and later Pasteur - inoculated individuals with attenuated or killed disease-causing agents. This empirical approach inspired a century of vaccine development and the effective prophylaxis of many infectious diseases. From the 1980s, several waves of new technologies have enabled the development of novel vaccines that would not have been possible using the empirical approach. The technological revolution in the field of vaccination is now continuing, and it is delivering novel and safer vaccines. In this Timeline article, we provide our views on the transition from empiricism to rational vaccine design. PMID:24925139

  6. Clinical and molecular aspects of the live attenuated Oka varicella vaccine.

    Science.gov (United States)

    Quinlivan, Mark; Breuer, Judy

    2014-07-01

    VZV is a ubiquitous member of the Herpesviridae family that causes varicella (chicken pox) and herpes zoster (shingles). Both manifestations can cause great morbidity and mortality and are therefore of significant economic burden. The introduction of varicella vaccination as part of childhood immunization programs has resulted in a remarkable decline in varicella incidence, and associated hospitalizations and deaths, particularly in the USA. The vaccine preparation, vOka, is a live attenuated virus produced by serial passage of a wild-type clinical isolate termed pOka in human and guinea pig cell lines. Although vOka is clinically attenuated, it can cause mild varicella, establish latency, and reactivate to cause herpes zoster. Sequence analysis has shown that vOka differs from pOka by at least 42 loci; however, not all genomes possess the novel vOka change at all positions, creating a heterogeneous population of genetically distinct haplotypes. This, together with the extreme cell-associated nature of VZV replication in cell culture and the lack of an animal model, in which the complete VZV life cycle can be replicated, has limited studies into the molecular basis for vOka attenuation. Comparative studies of vOka with pOka replication in T cells, dorsal root ganglia, and skin indicate that attenuation likely involves multiple mutations within ORF 62 and several other genes. This article presents an overview of the clinical aspects of the vaccine and current progress on understanding the molecular mechanisms that account for the clinical phenotype of reduced virulence. PMID:24687808

  7. 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

  8. The Role of Praziquantel- chemoprophylaxis and UV-attenuated Vaccine in Protecting Mice Against S. Mansoni Infection

    International Nuclear Information System (INIS)

    Potential control of schistosomiasis rely on multiple and integrated strategies, including vaccine production, chemotherapy and combination between chemotherapy and vaccination. The present work was conducted to evaluate the efficacy of combined PZQ- treatment with PZQ-chemoprophylaxis (PZQ-pretreatment) and UV-attenuated cercarial vaccination for the control of schistosomiasis. In the present work the induced levels of protection induced in vaccinated and vaccinated-PZQ-treated as well as, PZQ-pretreated and PZQ-pretreated followed by PZQ-treatment will be discussed. Results revealed that UV-Irradiated Vaccinated and vaccinated-PZQ-treated and PZQ-pretreated followed by PZQ-treated post challenged groups induced high levels of worm burdens reduction and mild pathological changes in both liver and intestine. Meanwhile, PZQ-pretreated alone failed to induce significant protection

  9. Status of vaccine research and development of vaccines for GBS.

    Science.gov (United States)

    Heath, Paul T

    2016-06-01

    Streptococcus agalactiae (group B streptococcus (GBS)) is the leading cause of neonatal sepsis and meningitis in many countries. Intrapartum antibiotic strategies have reduced the incidence of early-onset neonatal GBS in a number of countries but have had no impact on late onset GBS infection (LOD). In low/middle income settings, the disease burden remains uncertain although in several countries of Southern Africa appears comparable to or higher than that of high-income countries. As disease may be rapidly fulminating cases can be missed before appropriate samples are obtained and this may lead to underestimation of the true burden. Given the rapid onset and progression within hours of birth as well as the deficiencies in IAP strategies and absence of a solution for preventing LOD, it is clear that administration of a suitable vaccine in pregnancy could provide a better solution in all settings; it should also be cost effective. The current leading vaccine candidates are CPS-protein conjugate vaccines but protein-based vaccines are also in development and one has recently commenced clinical trials. PMID:26988258

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

    Institute of Scientific and Technical Information of China (English)

    FU Chuan-xi; NIE Jun; LIANG Jian-hua; WANG Ming

    2009-01-01

    Background Mumps virus infection is a potentially serious viral infection of childhood and early adulthood. In China, live attenuated S79 mumps vaccine has been licensed for pediatric use since 1990. The objective of this study was to determine the effectiveness of live attenuated S79 mumps vaccine against clinical mumps in outbreaks.Methods 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 S79 vaccine with 95% confidence intervals (CI).Results One hundred and ninety-four cases and 194 controls were enrolled into the study. VE of the S79 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.Conclusion The live attenuated S79 mumps vaccine can be effective in preventing clinical mumps outbreaks.

  11. In vitro Intestinal Mucosal Epithelial Responses to Wild-Type Salmonella Typhi and Attenuated Typhoid Vaccines.

    Science.gov (United States)

    Fiorentino, Maria; Lammers, Karen M; Levine, Myron M; Sztein, Marcelo B; Fasano, Alessio

    2013-01-01

    Typhoid fever, caused by S. Typhi, is responsible for approximately 200,000 deaths per year worldwide. Little information is available regarding epithelium-bacterial interactions in S. Typhi infection. We have evaluated in vitro the effects of wild-type S. Typhi, the licensed Ty21a typhoid vaccine and the leading strains CVD 908-htrA and CVD 909 vaccine candidates on intestinal barrier function and immune response. Caco2 monolayers infected with wild-type S. Typhi exhibited alterations in the organization of tight junctions, increased paracellular permeability, and a rapid decrease in Trans-Epithelial Electrical Resistance as early as 4 h post-exposure. S. Typhi triggered the secretion of interleukin (IL)-8 and IL-6. Caco2 cells infected with the attenuated strains exhibited a milder pro-inflammatory response with minimal disruption of the barrier integrity. We conclude that wild-type S. Typhi causes marked transient alterations of the intestinal mucosa that are more pronounced than those observed with Ty21a or new generation attenuated typhoid vaccine candidates. PMID:23408152

  12. Drones Could Deliver Vaccines in Developing Countries

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_159549.html Drones Could Deliver Vaccines in Developing Countries Machines might ... Right now, people often associate the use of drones with warfare. But in the future they could ...

  13. Construction of recombinant attenuated Salmonella typhimurium DNA vaccine expressing H pylori ureB and IL-2

    Institute of Scientific and Technical Information of China (English)

    Can Xu; Zhao-Shen Li; Yi-Qi Du; Yan-Fang Gong; Hua Yang; Bo Sun; Jing Jin

    2007-01-01

    ureB and IL-2 genes was successfully constructed and the specific strips of UreB and IL-2 expressed by recombinant plasmids were detected through Western blot. Study in vivo showed that the positive rate of rapid urease test of the immunized group including ureB and ureB-IL-2 was 37.5% and 12.5% respectively, and was significantly lower than that (100%) in the control group (P < 0.01).CONCLUSION: Recombinant attenuated Salmonella typhimurium DNA vaccine expressing UreB protein and IL-2 protein with immunogenicity can be constructed. It can protect mice against H pylori infection, which may help the development of a human-use H pylori DNA vaccine.

  14. The Feasibility of Gamma Irradiation for Developing Malaria Vaccine

    International Nuclear Information System (INIS)

    Malaria, a plasmodial disease, causes more than one million deaths per year and has a significant public health impact. Improved access to prompt treatment with effective antimalarial drugs need to be conducted for prevention of infection in high risk groups. However, the parasite as causal agent has exhibited a potential danger of wide-spread resistances. This warning has directed attention to the study of alternative methods of protection against the disease, among them is to do the immunization. A deeper understanding of the nature and regulation of protective immune mechanisms against this parasite will facilitate the development of much needed vaccines. Developing a malaria vaccine remains an enormous scientific, technical, and financial challenge. Currently a vaccine is not fully available. Among the practical applications of radiobiological techniques that may be of considerable interest for public health is the use of ionizing radiation in the preparation of vaccines. Convincing data were reported that sporozoites of Plasmodium berghei irradiated with X- or gamma-rays, provide an antigenic stimulus effective to induce a protective immune response in mice and rats against subsequent sporozoite infection. Irradiated parasites are better immunogens than killed ones and although non-infective they are still metabolically active, as shown by continued protein and nucleic acid synthesis. There is a substantial number of data from human studies demonstrating that sporozoites attenuated by radiation are potent inducer of protective immunity and that they are safe and do not give rise to the asexual erythrocytic infections that cause malaria. This vaccine is relatively inexpensive to produce, easy to store, and transportable without refrigeration. A long-term effort and commitment to providing resources must be maintained and increased to achieve the goal of a malaria vaccine candidate where ionizing radiation as a tool to prepare is seemingly feasible. (author)

  15. The Feasibility of Gamma Irradiation for Developing Malaria Vaccine

    Directory of Open Access Journals (Sweden)

    M. Syaifudin

    2011-12-01

    Full Text Available Malaria, a plasmodial disease, causes more than one million deaths per year and has a significant public health impact. Improved access to prompt treatment with effective antimalarial drugs need to be conducted for prevention of infection in high risk groups. However, the parasite as causal agent has exhibited a potential danger of wide-spread resistances. This warning has directed attention to the study of alternative methods of protection against the disease, among them is to do the immunization. A deeper understanding of the nature and regulation of protective immune mechanisms against this parasite will facilitate the development of much needed vaccines. Developing a malaria vaccine remains an enormous scientific, technical, and financial challenge. Currently a vaccine is not fully available. Among the practical applications of radiobiological techniques that may be of considerable interest for public health is the use of ionizing radiation in the preparation of vaccines. Convincing data were reported that sporozoites of Plasmodium berghei irradiated with X- or gamma-rays, provide an antigenic stimulus effective to induce a protective immune response in mice and rats against subsequent sporozoite infection. Irradiated parasites are better immunogens than killed ones and although non-infective they are still metabolically active, as shown by continued protein and nucleic acid synthesis. There is a substantial number of data from human studies demonstrating that sporozoites attenuated by radiation are potent inducers of protective immunity and that they are safe and do not give rise to the asexual erythrocytic infections that cause malaria. This vaccine is relatively inexpensive to produce, easy to store, and transportable without refrigeration. A long-term effort and commitment to providing resources must be maintained and increased to achieve the goal of a malaria vaccine candidate where ionizing radiation as a tool to prepare is seemingly

  16. An Alternative and Effective HIV Vaccination Approach Based on Inhibition of Antigen Presentation Attenuators in Dendritic Cells.

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available BACKGROUND: Current efforts to develop HIV vaccines that seek to stimulate immune responses have been disappointing, underscoring the inability of natural immune responses to control HIV-1 infection. Here we tested an alternative strategy to induce anti-HIV immune responses by inhibiting a host's natural immune inhibitor. METHODS AND FINDINGS: We used small interfering RNA (siRNA to inhibit suppressor of cytokine signaling (SOCS 1, a key negative regulator of the JAK/STAT pathway, and investigated the effect of this silencing on the ability of dendritic cells (DCs to induce anti-HIV-1 immunity. We found that SOCS1-silenced DCs broadly induced enhanced HIV-1 envelope (Env-specific CD8(+ cytotoxic T lymphocytes and CD4(+ T helper cells, as well as antibody responses, in mice. Importantly, SOCS1-silenced DCs were more resistant to HIV Env-mediated suppression and were capable of inducing memory HIV Env-specific antibody and T cell responses. SOCS1-restricted signaling, as well as production of proinflammatory cytokines such as interleukin-12 by DCs, play a critical role in regulating the anti-HIV immune response. Furthermore, the potency of HIV DNA vaccination is significantly enhanced by coimmunization with SOCS1 siRNA expressor DNA. CONCLUSIONS: This study demonstrates that SOCS1 functions as an antigen presentation attenuator to control both HIV-1-specific humoral and cellular responses. This study represents the first, to our knowledge, attempt to elicit HIV-specific T cell and antibody responses by inhibiting a host's antigen presentation attenuator, which may open a new and alternative avenue to develop effective therapeutic and prophylactic HIV vaccines.

  17. Development and efficacy of a novobiocin-resistant Streptococcus iniae as a novel vaccine in Nile tilapia (Oreochromis niloticus)

    Science.gov (United States)

    A novel attenuated Streptococcus iniae vaccine was developed from a virulent strain of Streptococcus iniae through selection for novobiocin resistance. The safety of the novel vaccine (named ISNO) was then evaluated in Nile tilapia (Oreochromis niloticus) through intraperitoneal (IP) injection. When...

  18. Need of cost-effective vaccines in developing countries: What plant biotechnology can offer?

    OpenAIRE

    Waheed, Mohammad Tahir; Sameeullah, Muhammad; Khan, Faheem Ahmed; Syed, Tahira; Ilahi, Manzoor; Gottschamel, Johanna; Lössl, Andreas Günter

    2016-01-01

    To treat current infectious diseases, different therapies are used that include drugs or vaccines or both. Currently, the world is facing an increasing problem of drug resistance from many pathogenic microorganisms. In majority of cases, when vaccines are used, formulations consist of live attenuated microorganisms. This poses an additional risk of infection in immunocompromised patients and people suffering from malnutrition in developing countries. Therefore, there is need to improve drug t...

  19. 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.

  20. Vaccine development for tuberculosis: current progress

    OpenAIRE

    Orme, Ian M.

    2013-01-01

    Very substantial efforts have been made over the past decade or more to develop vaccines against tuberculosis. Historically, this began with a view to replace the current vaccine, BCG, but more recently most candidates are either new forms of this bacillus, or are designed to boost immunity in children given BCG as infants. Good progress is being made, but very few have as yet progressed into clinical trials. The leading candidate has advanced to Phase IIb efficacy testing, with disappointing...

  1. Next-Generation Bacillus anthracis Live Attenuated Spore Vaccine Based on the htrA(-) (High Temperature Requirement A) Sterne Strain.

    Science.gov (United States)

    Chitlaru, Theodor; Israeli, Ma'ayan; Bar-Haim, Erez; Elia, Uri; Rotem, Shahar; Ehrlich, Sharon; Cohen, Ofer; Shafferman, Avigdor

    2016-01-01

    Anthrax is a lethal disease caused by the gram-positive spore-producing bacterium Bacillus anthracis. Live attenuated vaccines, such as the nonencapsulated Sterne strain, do not meet the safety standards mandated for human use in the Western world and are approved for veterinary purposes only. Here we demonstrate that disrupting the htrA gene, encoding the chaperone/protease HtrA (High Temperature Requirement A), in the virulent Bacillus anthracis Vollum strain results in significant virulence attenuation in guinea pigs, rabbits and mice, underlying the universality of the attenuated phenotype associated with htrA knockout. Accordingly, htrA disruption was implemented for the development of a Sterne-derived safe live vaccine compatible with human use. The novel B. anthracis SterneΔhtrA strain secretes functional anthrax toxins but is 10-10(4)-fold less virulent than the Sterne vaccine strain depending on animal model (mice, guinea pigs, or rabbits). In spite of this attenuation, double or even single immunization with SterneΔhtrA spores elicits immune responses which target toxaemia and bacteremia resulting in protection from subcutaneous or respiratory lethal challenge with a virulent strain in guinea pigs and rabbits. The efficacy of the immune-protective response in guinea pigs was maintained for at least 50 weeks after a single immunization. PMID:26732659

  2. Recent Developments in Livestock and Wildlife Brucellosis Vaccination

    Science.gov (United States)

    Live attenuated brucellosis vaccines have been available for protecting domestic livestock against B. melitensis or B. abortus for more than 60 years. Current vaccines are effective in preventing abortion and transmission of brucellosis, but poor at preventing infection or seroconversion. In addit...

  3. Oral vaccination of mice with Trichinella spiralis nudix hydrolase DNA vaccine delivered by attenuated Salmonella elicited protective immunity.

    Science.gov (United States)

    Liu, Pei; Wang, Zhong Quan; Liu, Ruo Dan; Jiang, Peng; Long, Shao Rong; Liu, Li Na; Zhang, Xin Zhuo; Cheng, Xiang Chao; Yu, Chuan; Ren, Hui Jun; Cui, Jing

    2015-06-01

    We have previously reported that Trichinella spiralis Nudix hydrolase (TsNd) bound to intestinal epithelial cells (IECs), and the vaccination of mice with recombinant TsNd protein (rTsNd) produced a partial protective immunity against challenge infection in mice. In this study, the full-length cDNA sequence of TsNd gene was cloned into the eukaryotic expression plasmid pcDNA3.1, and the recombinant TsNd DNA was transformed into attenuated Salmonella typhimurium strain ⊿cyaSL1344. Oral immunization of mice with TsNd/S. typhimurium elicited a significant local mucosal IgA response and a systemic Th1/Th2 immune response. Cytokine profiling also showed a significant increase in the Th1 (IFN-γ, IL-2) and Th2 (IL-4, 10) responses in splenocytes of immunized mice upon stimulation with the rTsNd. The oral immunization of mice with TsNd/S. typhimurium displayed a statistically significant 73.32% reduction in adult worm burden and a 49.5% reduction in muscle larvae after challenge with T. spiralis muscle larvae, compared with PBS control group. Our results demonstrated that TsNd DNA delivered by attenuated live S. typhimurium elicited a local IgA response and a mixed Th1/Th2 immune response, and produced a partial protection against T. spiralis infection in mice. PMID:25733024

  4. Development of a BCG challenge model for the testing of vaccine candidates against tuberculosis in cattle.

    Science.gov (United States)

    Villarreal-Ramos, Bernardo; Berg, Stefan; Chamberlain, Laura; McShane, Helen; Hewinson, R Glyn; Clifford, Derek; Vordermeier, Martin

    2014-09-29

    Vaccination is being considered as part of a sustainable strategy for the control of bovine tuberculosis (BTB) in the UK. The live attenuated Mycobacterium bovis bacillus Calmette-Guerin (BCG) has been used experimentally to vaccinate cattle against BTB. However, BCG confers partial protection against BTB and therefore, there is a need to develop improved vaccines. BTB vaccine efficacy experiments require the use of biosafety level 3 facilities which are expensive to maintain, generally oversubscribed and represent a bottle neck for the testing of vaccine candidates. One indicator of the induction of protective responses would be the ability of the host's immune response to control/kill mycobacteria. In this work we have evaluated an intranodal BCG challenge for the selection of vaccine candidates at biosafety level 2 which are capable of inducing mycobactericidal responses. To our knowledge, this is the first such report. Whilst BCG only confers partial protection, it is still the standard against which other vaccines are judged. Therefore we tested the BCG intranodal challenge in BCG (Danish strain) vaccinated cattle and showed that vaccinated cattle had lower BCG cfu counts than naïve cattle at 14 and 21 days after intranodal challenge with BCG (Tokyo strain). This model could help prioritize competing TB vaccine candidates and exploration of primary and secondary immune responses to mycobacteria. PMID:25138291

  5. The Magnitude of Local Immunity in the Lungs of Mice Induced by Live Attenuated Influenza Vaccines Is Determined by Local Viral Replication and Induction of Cytokines▿ †

    OpenAIRE

    Lau, Yuk-Fai; Santos, Celia; Torres-Vélez, Fernando J.; Subbarao, Kanta

    2010-01-01

    While live attenuated influenza vaccines (LAIVs) have been shown to be efficacious and have been licensed for human use, the surface glycoproteins hemagglutinin (HA) and neuraminidase (NA) have to be updated for optimal protective efficacy. Little is known about the effect of different HA and NA proteins on the immunogenicity of LAIVs developed using the same backbone. A panel of LAIVs that share the internal protein genes, with unique HA and NA gene segments from different influenza subtypes...

  6. Antibody response in animals immunized after oral delivery of attenuated liver hepatitis a vaccine

    International Nuclear Information System (INIS)

    The microspheres were prepared by encapsulating live attenuated hepatitis A vaccine with PLA/PLG, and the rhesus monkeys and mice were immunized by such microspheres through oral route. Then serum was collected to detect the HAV-IgM, HAV-IgG, HAV-IgA with EIA, so as to find a convenient immunization way. Results showed that HAV-IgG in rhesus monkeys was detected in the 3rd week and reached a peak value (1267mlU/mL), and then decreased by degrees. HAV-IgM titer was 1:4000. After an oral booster was given, the HAV-IgG level increased, and HAV-IgM titer was 1:1000. The level reached 1244mIU/mL after challenge with wild virus strain, and HAV-IgM was 1:100. HAV-IgM was detected in the control group only after challenge with wild virus strain. HAV-IgG in mice was detected in the 2nd week and reached a peak value in the 4th week. HAV S-IgA was detected in the 1st week and reached a peak value in the 4th week. Antibody response was induced in the rhesus monkeys after oral delivery of the biodegradable microspheres containing live attenuated HA vaccine. The results in mice were similar with the report but the anti-HAV was present earlier as compared with rhesus monkeys. (authors)

  7. Vaccination of chicks against Plasmodium gallinaceum by erythrocytic and exoerythrocytic parasites attenuated by gamma irradiation

    International Nuclear Information System (INIS)

    Plasmodium gallinaceum-infected blood which received up to 24 krad during exposure to gamma-rays from a cobalt-60 source produced infections of normal course and duration when injected into chickens. The prepatent period advanced with increasing exposure of infected blood to radiation, suggesting some degree of attenuation. At 26, 28 and 30 krad, the infections were transient and the parasites were morphologically abnormal. It is thought that the amount of radiation required to render the parasites non-viable is about 45 krad for an inoculum of 106 parasites. There is evidence that exoerythrocytic stages may be more susceptible to gamma-rays than are blood parasites. Chickens were inoculated three times, over a period of four weeks, with vaccines prepared from gamma-irradiated infected blood and brain tissue. Half the birds which had been inoculated with attenuated parasitized blood exhibited mild infections during vaccination, and they were the only birds to show at challenge immunity to both homologous blood and exoerythrocytic parasites. (author)

  8. 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

  9. New approaches to the development of virus vaccines for veterinary use.

    Science.gov (United States)

    Yamanouchi, K; Barrett, T; Kai, C

    1998-12-01

    The marked progress in recombinant deoxyribonucleic acid (DNA) technology during the past decade has led to the development of a variety of safe new vaccine vectors which are capable of efficiently expressing foreign immunogens. These have been based on a variety of virus types--poxviruses, herpesviruses and adenoviruses--and have led to the production of many new potential recombinant vaccines. Of these recombinant vaccines, the rabies vaccine, in which the rabies G protein is expressed in a vaccinia vector, has been widely used in the field to prevent the spread of rabies both in Europe and in the United States of America. A recombinant Newcastle disease virus vaccine, using fowlpox virus as the vector to express immunogenic proteins from the Newcastle disease virus, has been licensed as the first commercial recombinant vectored vaccine. Many other recombinant virus vaccines are still at the stage of laboratory or field testing. The most recent breakthrough in vaccinology has been the success with the use of naked DNA as a means of vaccination. This approach has shown great promise in mouse model systems and has now become the most active field in new vaccine development. Molecular redesigning of conventional ribonucleic acid (RNA) viruses to obtain more stable attenuated vaccines was previously possible only for positive-strand RNA viruses, such as poliovirus. However, recent advances in molecular biological techniques have enabled the rescuing of negative-strand viruses from DNA copies of their genomes. This has made it possible to engineer specific changes in the genomes of Rhabdoviridae and Paramyxoviridae, both of which include several viruses of veterinary importance. The authors describe the current progress in the development of vector vaccines, DNA vaccines and vaccines based on engineered positive- and negative-strand RNA virus genomes, with special emphasis on their application to diseases of veterinary importance. PMID:9850535

  10. Assessment of vaccination with schistosomules attenuated by using different doses of γ-radiation on experimental schistosomiasis mansoni

    International Nuclear Information System (INIS)

    Current strategies for the control of schistosomiasis are based primarily on chemotherapy but successful vaccination against infection has been also demonstrated in several host parasite models.The present study was designed to asses the immunogenic effects of the vaccination with autogenic targets in the form of schistosomula attenuated by different doses of γ-radiation (15, 20, 25 kilo rad) in mice challenged with S. mansoni cercariae as regard parasitological, histological, biochemical and immunological aspects.

  11. Pre- and post-exposure safety and efficacy of attenuated rabies virus vaccines are enhanced by their expression of IFNγ

    OpenAIRE

    Barkhouse, Darryll A.; Faber, Milosz; Hooper, D. Craig

    2014-01-01

    Consistent with evidence of a strong correlation between interferon gamma (IFNγ) production and rabies virus (RABV) clearance from the CNS, we recently demonstrated that engineering a pathogenic RABV to express IFNγ highly attenuates the virus. Reasoning that IFNγ expression by RABV vaccines would enhance their safety and efficacy, we reverse-engineered two proven vaccine vectors, GAS and GASGAS, to express murine IFNγ. Mortality and morbidity were monitored during suckling mice infection, im...

  12. Porcine circovirus type 2 (PCV2) infection decreases the efficacy of an attenuated classical swine fever virus (CSFV) vaccine

    OpenAIRE

    Huang Yu-Liang; Pang Victor; Lin Chun-Ming; Tsai Yi-Chieh; Chia Mi-Yuan; Deng Ming-Chung; Chang Chia-Yi; Jeng Chian-Ren

    2011-01-01

    Abstract The Lapinized Philippines Coronel (LPC) vaccine, an attenuated strain of classical swine fever virus (CSFV), is an important tool for the prevention and control of CSFV infection and is widely and routinely used in most CSF endemic areas, including Taiwan. The aim of this study was to investigate whether PCV2 infection affects the efficacy of the LPC vaccine. Eighteen 6-week-old, cesarean-derived and colostrum-deprived (CDCD), crossbred pigs were randomly assigned to four groups. A t...

  13. Development of a murine mycobacterial growth inhibition assay for evaluating vaccines against Mycobacterium tuberculosis.

    Science.gov (United States)

    Parra, Marcela; Yang, Amy L; Lim, JaeHyun; Kolibab, Kristopher; Derrick, Steven; Cadieux, Nathalie; Perera, Liyanage P; Jacobs, William R; Brennan, Michael; Morris, Sheldon L

    2009-07-01

    The development and characterization of new tuberculosis (TB) vaccines has been impeded by the lack of reproducible and reliable in vitro assays for measuring vaccine activity. In this study, we developed a murine in vitro mycobacterial growth inhibition assay for evaluating TB vaccines that directly assesses the capacity of immune splenocytes to control the growth of Mycobacterium tuberculosis within infected macrophages. Using this in vitro assay, protective immune responses induced by immunization with five different types of TB vaccine preparations (Mycobacterium bovis BCG, an attenuated M. tuberculosis mutant strain, a DNA vaccine, a modified vaccinia virus strain Ankara [MVA] construct expressing four TB antigens, and a TB fusion protein formulated in adjuvant) can be detected. Importantly, the levels of vaccine-induced mycobacterial growth-inhibitory responses seen in vitro after 1 week of coculture correlated with the protective immune responses detected in vivo at 28 days postchallenge in a mouse model of pulmonary tuberculosis. In addition, similar patterns of cytokine expression were evoked at day 7 of the in vitro culture by immune splenocytes taken from animals immunized with the different TB vaccines. Among the consistently upregulated cytokines detected in the immune cocultures are gamma interferon, growth differentiation factor 15, interleukin-21 (IL-21), IL-27, and tumor necrosis factor alpha. Overall, we have developed an in vitro functional assay that may be useful for screening and comparing new TB vaccine preparations, investigating vaccine-induced protective mechanisms, and assessing manufacturing issues, including product potency and stability. PMID:19458207

  14. DNA Vaccine Initiates Replication of Live Attenuated Chikungunya Virus In Vitro and Elicits Protective Immune Response in Mice

    OpenAIRE

    Tretyakova, Irina; Hearn, Jason; Wang, Eryu; Weaver, Scott; Pushko, Peter

    2014-01-01

    Background. Chikungunya virus (CHIKV) causes outbreaks of chikungunya fever worldwide and represents an emerging pandemic threat. Vaccine development against CHIKV has proved challenging. Currently there is no approved vaccine or specific therapy for the disease.

  15. Alternative Live-Attenuated Influenza Vaccines Based on Modifications in the Polymerase Genes Protect against Epidemic and Pandemic Flu▿

    OpenAIRE

    Solórzano, Alicia; Ye, Jianqiang; Pérez, Daniel R.

    2010-01-01

    Human influenza is a seasonal disease associated with significant morbidity and mortality. Influenza vaccination is the most effective means for disease prevention. We have previously shown that mutations in the PB1 and PB2 genes of the live-attenuated influenza vaccine (LAIV) from the cold-adapted (ca) influenza virus A/Ann Arbor/6/60 (H2N2) could be transferred to avian influenza viruses and produce partially attenuated viruses. We also demonstrated that avian influenza viruses carrying the...

  16. Vaccination of cats with an attenuated recombinant myxoma virus expressing feline calicivirus capsid protein.

    Science.gov (United States)

    McCabe, Victoria J; Tarpey, Ian; Spibey, Norman

    2002-06-01

    Myxoma virus, a member of the Poxviridae family (genus Leporipoxvirus) is the agent responsible for myxomatosis in the European rabbit. Recombinant myxoma viruses expressing the capsid gene of an F9 strain of feline calicivirus (FCV) were constructed from an apathogenic, laboratory attenuated, isolate of myxoma virus. The FCV capsid genes were recombined into the myxoma growth factor (MGF) locus of the myxoma genome and expressed from synthetic poxvirus promoters. Myxoma virus is unable to replicate productively in feline cells in vitro, however, cells infected with recombinant viruses do express the heterologous antigens from both late and early/late synthetic promoters. Cats immunised with myxoma-FCV recombinant virus generated high levels of serum neutralising antibody and were protected from disease on subsequent challenge with virulent FCV. Furthermore, there was no evidence of transmission of myxoma-FCV recombinant virus from vaccinated to non-vaccinated cats. These results demonstrate the potential of myxoma virus as a safe vaccine vector for use in non-lepori species and in particular the cat. PMID:12057600

  17. Heterotypic Dengue Infection with Live Attenuated Monotypic Dengue Virus Vaccines: Implications for Vaccination of Populations in Areas Where Dengue Is Endemic

    OpenAIRE

    Durbin, Anna P.; Schmidt, Alexander; Elwood, Dan; Wanionek, Kimberli A.; Lovchik, Janece; Thumar, Bhavin; Murphy, Brian R.; Whitehead, Stephen S.

    2011-01-01

    Background. Because infection with any of the 4 Dengue virus serotypes may elicit both protective neutralizing antibodies and nonneutralizing antibodies capable of enhancing subsequent heterotypic Dengue virus infections, the greatest risk for severe dengue occurs during a second, heterotypic Dengue virus infection. It remains unclear whether the replication of live attenuated vaccine viruses will be similarly enhanced when administered to Dengue-immune individuals.

  18. Development of vaccines for Plasmodium vivax malaria.

    Science.gov (United States)

    Mueller, Ivo; Shakri, Ahmad Rushdi; Chitnis, Chetan E

    2015-12-22

    Plasmodium vivax continues to cause significant morbidity outside Africa with more than 50% of malaria cases in many parts of South and South-east Asia, Pacific islands, Central and South America being attributed to P. vivax infections. The unique biology of P. vivax, including its ability to form latent hypnozoites that emerge months to years later to cause blood stage infections, early appearance of gametocytes before clinical symptoms are apparent and a shorter development cycle in the vector makes elimination of P. vivax using standard control tools difficult. The availability of an effective vaccine that provides protection and prevents transmission would be a valuable tool in efforts to eliminate P. vivax. Here, we review the latest developments related to P. vivax malaria vaccines and discuss the challenges as well as directions toward the goal of developing highly efficacious vaccines against P. vivax malaria. PMID:26428453

  19. Live attenuated influenza A virus vaccine protects against A(H1N1)pdm09 heterologous challenge without vaccine associated enhanced respiratory disease.

    Science.gov (United States)

    Gauger, Phillip C; Loving, Crystal L; Khurana, Surender; Lorusso, Alessio; Perez, Daniel R; Kehrli, Marcus E; Roth, James A; Golding, Hana; Vincent, Amy L

    2014-12-01

    Live-attenuated influenza virus (LAIV) vaccines may provide cross-protection against contemporary influenza A virus (IAV) in swine. Conversely, whole inactivated virus (WIV) vaccines have the potential risk of vaccine-associated enhanced respiratory disease (VAERD) when challenged with IAV of substantial antigenic drift. A temperature sensitive, intranasal H1N2 LAIV was compared to wild type exposure (WT) and an intramuscular WIV vaccine in a model shown to induce VAERD. WIV vaccinated swine challenged with pandemic A/H1N1 (H1N1pdm09) were not protected from infection and demonstrated severe respiratory disease consistent with VAERD. Lung lesions were mild and challenge virus was not detected in the respiratory tract of LAIV vaccinates. High levels of post-vaccination IgG serum antibodies targeting the H1N1pdm09 HA2 stalk domain were exclusively detected in the WIV group and associated with increased H1N1pdm09 virus infectivity in MDCK cells. In contrast, infection-enhancing antibodies were not detected in the serum of LAIV vaccinates and VAERD was not observed. PMID:25461535

  20. Effects of challenge with a virulent genotype II strain of porcine reproductive and respiratory syndrome virus on piglets vaccinated with an attenuated genotype I strain vaccine.

    Science.gov (United States)

    Roca, M; Gimeno, M; Bruguera, S; Segalés, J; Díaz, I; Galindo-Cardiel, I J; Martínez, E; Darwich, L; Fang, Y; Maldonado, J; March, R; Mateu, E

    2012-07-01

    Porcine reproductive and respiratory syndrome virus (PRRSV) is endemic in most parts of Asia, where genotype I and II strains of diverse virulence may coexist. This study evaluated the outcome of infection with a highly virulent Asian genotype II PRRSV isolate in piglets vaccinated with a genotype I vaccine. Twenty-one 3-week-old piglets were divided in three groups: Pigs in group V (n=8) were vaccinated with an attenuated genotype I commercial PRRSV vaccine, while pigs in group U (n=8) and a control group (group C; n=5) were unvaccinated; 6 weeks later, pigs in groups V and U were challenged intranasally with a highly virulent strain of genotype II PRRSV (1×10(5) 50% tissue culture infectious doses/mL), while pigs in group C received a placebo. Over a period of 21 days after challenge, vaccinated pigs had significantly lower mortality (0/8 versus 2/8), fewer days of fever, a lower frequency of catarrhal bronchopneumonia, higher weight gains (13.4 versus 6.6 kg) and lower levels of viraemia compared to unvaccinated challenged pigs. Immunisation with a genotype I attenuated PRRSV vaccine provided partial protection against challenge with a highly virulent genotype II strain. PMID:22264642

  1. 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.

  2. Safety and protective efficacy of a spiC and crp deletion mutant of Salmonella gallinarum as a live attenuated vaccine for fowl typhoid.

    Science.gov (United States)

    Cheng, Zhao; Yin, Junlei; Kang, Xilong; Geng, Shizhong; Hu, Maozhi; Pan, Zhiming; Jiao, Xinan

    2016-08-01

    With an aim to develop a safe, immunogenic fowl typhoid (FT) vaccine, the safety and efficacy of 1009ΔspiCΔcrp, a spiC and crp deletion mutant of Salmonella gallinarum, were evaluated in chickens. Three-day-old chickens were intramuscularly immunized with 1009ΔspiCΔcrp (1×10(7)CFU) and boosted 7days later (at 10-days old) with the same dose and via the same route (vaccinated group). The vaccinated group showed no clinical symptoms and no differences in body weight compared to the unvaccinated control group. 1009ΔspiCΔcrp bacteria colonized and persisted in the liver and spleen of vaccinated chickens for >14days, and significant specific humoral and cellular immune responses were induced. Vaccinated chickens were challenged with S. gallinarum strain SG9 at 21days post-immunization (24-day-old chickens), and efficient protection was observed based on the mortality and clinical symptoms, as compared to those in the control group. These results demonstrate that 1009ΔspiCΔcrp can be used as a live attenuated vaccine. PMID:27473974

  3. Protection of SA14-14-2 live attenuated Japanese encephalitis vaccine against the wild-type JE viruses

    Institute of Scientific and Technical Information of China (English)

    贾丽丽; 王志伟; 俞永新

    2003-01-01

    ObjectiveTo explore on the immunity of live attenuated Japanese Encephalitis (JE) vaccine(SA14-14-2) to different wild JE virus (JEV) strains. MethodsThe neutralizing effect of the vaccine against different wild JE virus strains was detected by plaque reduction neutralization test (PRNT), and the immunogenicity was studied on mice by vaccination -challenge protection test. In the PRNT , pooled sera from vaccinated human were tested against 10 strains of JEV , one isolated in Taiwan and 9 from other Asian countries.In the vaccination challenge test, mice received one dose of the live vaccine subcutaneously and were challenged intraperitoneally 14 days later against 22 JEV virus strains, 11 were isolated in China and the other 11 from Tailand, Vietnahailam, Indonesia, India, Philippines and Japan. ResultsThe protection rates to all the 22 challenge virus were 90%-100% when 340 PFU/0.1 ml vaccinate virus was administered. The neutralizing effect showed that all the JEV isolates many have neutralized by the sera. ConclusionSA14-14-2 live attenuated prepared with strain SA14-14-2 is broadly immunogenic and may have effective protection against in Asian JE affected countries.

  4. Molecularly engineered live-attenuated chimeric West Nile/dengue virus vaccines protect rhesus monkeys from West Nile virus

    International Nuclear Information System (INIS)

    Two molecularly engineered, live-attenuated West Nile virus (WN) vaccine candidates were highly attenuated and protective in rhesus monkeys. The vaccine candidates are chimeric viruses (designated WN/DEN4) bearing the membrane precursor and envelope protein genes of WN on a backbone of dengue 4 virus (DEN4) with or without a deletion of 30 nucleotides (Δ30) in the 3' noncoding region of DEN4. Viremia in WN/DEN4- infected monkeys was reduced 100-fold compared to that in WN- or DEN4-infected monkeys. WN/DEN4-3'Δ30 did not cause detectable viremia, indicating that it is even more attenuated for monkeys. These findings indicate that chimerization itself and the presence of the Δ30 mutation independently contribute to the attenuation phenotype for nonhuman primates. Despite their high level of attenuation in monkeys, the chimeras induced a moderate-to-high titer of neutralizing antibodies and prevented viremia in monkeys challenged with WN. The more attenuated vaccine candidate, WN/DEN4-3'Δ30, will be evaluated first in our initial clinical studies

  5. Gene-based vaccine development for improving animal production in developing countries

    International Nuclear Information System (INIS)

    Full text: The cloning and expression of microbial genes in alternate hosts to enhance production of antigens for animal vaccines against all disease is theoretically achievable. It is essential, however, that antigens expressed in this way are known to be protective. Many years of costly research usually precedes the identification of such antigens or combinations of antigens. Thus, while conventional vaccines based on living, attenuated or inactivated microorganisms may be effective, the protective components contained in them i.e. the candidates for cloning, have yet to be found. The principal protective antigen in vaccines against foot rot of sheep and goats is fimbrial protein of Dichelobacter nodosus. Recombinant vaccines against this infection are ineffective if the protein subunits are not assembled and presented to the host in a manner morphologically indistinguishable from those of the natural fimbriae. Availability of recombinant antigen does not necessarily avoid the need for the use of adjuvants to potentiate response. Oil emulsion vaccines, while enhancing immune response, almost inevitably cause a marked reaction at the site of injection. Livestock owners in developing countries are as likely as those elsewhere to object to these reactions. The need to find an acceptable and effective formulation adds to the cost of recombinant vaccines and their application in countries with limited resources for disease control. Another costly feature of recombinant vaccines has been the patenting of processes involving gene technology and licencing agreements for production under the protection of these patents. In some systems antigenic competition between similar and disparate antigens limits the usefulness of even recombinant antigens that, administered individually, are highly potent. In the case of programs for the control and eventual eradication of footrot in sheep and goats in Nepal this problem was overcome by the prior identification of causal serotypes

  6. Attenuated Salmonella typhimurium delivering DNA vaccine encoding duck enteritis virus UL24 induced systemic and mucosal immune responses and conferred good protection against challenge

    Directory of Open Access Journals (Sweden)

    Yu Xia

    2012-07-01

    Full Text Available Abstract Orally delivered DNA vaccines against duck enteritis virus (DEV were developed using live attenuated Salmonella typhimurium (SL7207 as a carrier and Escherichia coli heat labile enterotoxin B subunit (LTB as a mucosal adjuvant. DNA vaccine plasmids pVAX-UL24 and pVAX-LTB-UL24 were constructed and transformed into attenuated Salmonella typhimurium SL7207 resulting SL7207 (pVAX-UL24 and SL7207 (pVAX-LTB-UL24 respectively. After ducklings were orally inoculated with SL7207 (pVAX-UL24 or SL7207 (pVAX-LTB-UL24, the anti-DEV mucosal and systemic immune responses were recorded. To identify the optimum dose that confers maximum protection, we used different doses of the candidate vaccine SL7207 (pVAX-LTB-UL24 during oral immunization. The strongest mucosal and systemic immune responses developed in the SL7207 (pVAX-LTB-UL24 (1011 CFU immunized group. Accordingly, oral immunization of ducklings with SL7207 (pVAX-LTB-UL24 showed superior efficacy of protection (60-80% against a lethal DEV challenge (1000 LD50, compared with the limited survival rate (40% of ducklings immunized with SL7207 (pVAX-UL24. Our study suggests that the SL7207 (pVAX-LTB-UL24 can be a candidate DEV vaccine.

  7. H7N9 Live Attenuated Influenza Vaccine Is Highly Immunogenic, Prevents Virus Replication, and Protects Against Severe Bronchopneumonia in Ferrets.

    Science.gov (United States)

    de Jonge, Jørgen; Isakova-Sivak, Irina; van Dijken, Harry; Spijkers, Sanne; Mouthaan, Justin; de Jong, Rineke; Smolonogina, Tatiana; Roholl, Paul; Rudenko, Larisa

    2016-05-01

    Avian influenza viruses continue to cross the species barrier, and if such viruses become transmissible among humans, it would pose a great threat to public health. Since its emergence in China in 2013, H7N9 has caused considerable morbidity and mortality. In the absence of a universal influenza vaccine, preparedness includes development of subtype-specific vaccines. In this study, we developed and evaluated in ferrets an intranasal live attenuated influenza vaccine (LAIV) against H7N9 based on the A/Leningrad/134/17/57 (H2N2) cold-adapted master donor virus. We demonstrate that the LAIV is attenuated and safe in ferrets and induces high hemagglutination- and neuraminidase-inhibiting and virus-neutralizing titers. The antibodies against hemagglutinin were also cross-reactive with divergent H7 strains. To assess efficacy, we used an intratracheal challenge ferret model in which an acute severe viral pneumonia is induced that closely resembles viral pneumonia observed in severe human cases. A single- and two-dose strategy provided complete protection against severe pneumonia and prevented virus replication. The protective effect of the two-dose strategy appeared better than the single dose only on the microscopic level in the lungs. We observed, however, an increased lymphocytic infiltration after challenge in single-vaccinated animals and hypothesize that this a side effect of the model. PMID:26796670

  8. Single-cycle immunodeficiency viruses provide strategies for uncoupling in vivo expression levels from viral replicative capacity and for mimicking live-attenuated SIV vaccines

    International Nuclear Information System (INIS)

    To reduce the risks associated with live-attenuated immunodeficiency virus vaccines, single-cycle immunodeficiency viruses (SCIVs) were developed by primer complementation and production of the vaccine in the absence of vif in a vif-independent cell line. After a single intravenous injection of SCIVs into rhesus monkeys, peak viral RNA levels of 103 to 104 copies/ml plasma were observed, indicating efficient expression of SCIV in the vaccinee. After booster immunizations with SCIVs, SIV-specific humoral and cellular immune responses were observed. Although the vaccine doses used in this pilot study could not protect vaccinees from subsequent intravenous challenge with pathogenic SIVmac239, our results demonstrate that the novel SCIV approach allows us to uncouple in vivo expression levels from the viral replicative capacity facilitating the analysis of the relationship between viral expression levels or viral genes and immune responses induced by SIV

  9. Effect of CD8+ Lymphocyte Depletion on Virus Containment after Simian Immunodeficiency Virus SIVmac251 Challenge of Live Attenuated SIVmac239Δ3-Vaccinated Rhesus Macaques

    OpenAIRE

    Schmitz, Jörn E.; Johnson, R. Paul; McClure, Harold M.; Manson, Kelledy H.; Wyand, Michael S.; Kuroda, Marcelo J.; Lifton, Michelle A.; Khunkhun, Rajinder S.; McEvers, Kimberly J.; Gillis, Jacqueline; Piatak, Michael; Lifson, Jeffrey D.; Grosschupff, Gudrun; Racz, Paul; Tenner-Racz, Klara

    2005-01-01

    Although live attenuated vaccines can provide potent protection against simian immunodeficiency virus (SIV) and simian-human immunodeficiency virus challenges, the specific immune responses that confer this protection have not been determined. To test whether cellular immune responses mediated by CD8+ lymphocytes contribute to this vaccine-induced protection, we depleted rhesus macaques vaccinated with the live attenuated virus SIVmac239Δ3 of CD8+ lymphocytes and then challenged them with SIV...

  10. Protection induced by commercially available live-attenuated and recombinant viral vector vaccines against infectious laryngotracheitis virus in broiler chickens.

    Science.gov (United States)

    Vagnozzi, Ariel; Zavala, Guillermo; Riblet, Sylva M; Mundt, Alice; García, Maricarmen

    2012-01-01

    Viral vector vaccines using fowl poxvirus (FPV) and herpesvirus of turkey (HVT) as vectors and carrying infectious laryngotracheitis virus (ILTV) genes are commercially available to the poultry industry in the USA. Different sectors of the broiler industry have used these vaccines in ovo or subcutaneously, achieving variable results. The objective of the present study was to determine the efficacy of protection induced by viral vector vaccines as compared with live-attenuated ILTV vaccines. The HVT-LT vaccine was more effective than the FPV-LT vaccine in mitigating the disease and reducing levels of challenge virus when applied in ovo or subcutaneously, particularly when the challenge was performed at 57 days rather than 35 days of age. While the FPV-LT vaccine mitigated clinical signs more effectively when administered subcutaneously than in ovo, it did not reduce the concentration of challenge virus in the trachea by either application route. Detection of antibodies against ILTV glycoproteins expressed by the viral vectors was a useful criterion to assess the immunogenicity of the vectors. The presence of glycoprotein I antibodies detected pre-challenge and post challenge in chickens vaccinated with HVT-LT indicated that the vaccine induced a robust antibody response, which was paralleled by significant reduction of clinical signs. The chicken embryo origin vaccine provided optimal protection by significantly mitigating the disease and reducing the challenge virus in chickens vaccinated via eye drop. The viral vector vaccines, applied in ovo and subcutaneously, provided partial protection, reducing to some degree clinical signs, and challenge VIRUS replication in the trachea. PMID:22845318

  11. Mycobacterium tuberculosis infection and vaccine development.

    Science.gov (United States)

    Tang, Jiansong; Yam, Wing-Cheong; Chen, Zhiwei

    2016-05-01

    Following HIV/AIDS, tuberculosis (TB) continues to be the second most deadly infectious disease in humans. The global TB prevalence has become worse in recent years due to the emergence of multi-drug resistant (MDR) and extensively-drug resistant (XDR) strains, as well as co-infection with HIV. Although Bacillus Calmette-Guérin (BCG) vaccine has nearly been used for a century in many countries, it does not protect adult pulmonary tuberculosis and even causes disseminated BCG disease in HIV-positive population. It is impossible to use BCG to eliminate the Mycobacterium tuberculosis (M. tb) infection or to prevent TB onset and reactivation. Consequently, novel vaccines are urgently needed for TB prevention and immunotherapy. In this review, we discuss the TB prevalence, interaction between M. tb and host immune system, as well as recent progress of TB vaccine research and development. PMID:27156616

  12. Pre- and post-exposure safety and efficacy of attenuated rabies virus vaccines are enhanced by their expression of IFNγ

    International Nuclear Information System (INIS)

    Consistent with evidence of a strong correlation between interferon gamma (IFNγ) production and rabies virus (RABV) clearance from the CNS, we recently demonstrated that engineering a pathogenic RABV to express IFNγ highly attenuates the virus. Reasoning that IFNγ expression by RABV vaccines would enhance their safety and efficacy, we reverse-engineered two proven vaccine vectors, GAS and GASGAS, to express murine IFNγ. Mortality and morbidity were monitored during suckling mice infection, immunize/challenge experiments and mixed intracranial infections. We demonstrate that GASγ and GASγGAS are significantly attenuated in suckling mice compared to the GASGAS vaccine. GASγ better protects mice from lethal DRV4 RABV infection in both pre- and post-exposure experiments compared to GASGAS. Finally, GASγGAS reduces post-infection neurological sequelae, compared to control, during mixed intracranial infection with DRV4. These data show IFNγ expression by a vaccine vector can enhance its safety while increasing its efficacy as pre- and post-exposure treatment. - Highlights: • IFNγ expression improves attenuated rabies virus safety and immunogenicity. • IFNγ expression is safer and more immunogenic than doubling glycoprotein expression. • Co-infection with IFNγ-expressing RABV prevents wild-type rabies virus lethality. • Vaccine safety and efficacy is additive for IFNγ and double glycoprotein expression

  13. Pre- and post-exposure safety and efficacy of attenuated rabies virus vaccines are enhanced by their expression of IFNγ

    Energy Technology Data Exchange (ETDEWEB)

    Barkhouse, Darryll A. [Department of Cancer Biology, 1020 Locust St., Jefferson Alumni Hall, Room 454, Philadelphia, PA 19107 (United States); Center for Neurovirology 1020 Locust St., Jefferson Alumni Hall, Room 454, Philadelphia, PA 19107 (United States); Faber, Milosz [Center for Neurovirology 1020 Locust St., Jefferson Alumni Hall, Room 454, Philadelphia, PA 19107 (United States); Department of Microbiology and Immunology 1020 Locust St., Jefferson Alumni Hall, Room 465, Philadelphia, PA 19107 (United States); Hooper, D. Craig, E-mail: douglas.hooper@jefferson.edu [Department of Cancer Biology, 1020 Locust St., Jefferson Alumni Hall, Room 454, Philadelphia, PA 19107 (United States); Department of Neurological Surgery, 1020 Locust St., Jefferson Alumni Hall, Room 454, Philadelphia, PA 19107 (United States); Center for Neurovirology 1020 Locust St., Jefferson Alumni Hall, Room 454, Philadelphia, PA 19107 (United States)

    2015-01-01

    Consistent with evidence of a strong correlation between interferon gamma (IFNγ) production and rabies virus (RABV) clearance from the CNS, we recently demonstrated that engineering a pathogenic RABV to express IFNγ highly attenuates the virus. Reasoning that IFNγ expression by RABV vaccines would enhance their safety and efficacy, we reverse-engineered two proven vaccine vectors, GAS and GASGAS, to express murine IFNγ. Mortality and morbidity were monitored during suckling mice infection, immunize/challenge experiments and mixed intracranial infections. We demonstrate that GASγ and GASγGAS are significantly attenuated in suckling mice compared to the GASGAS vaccine. GASγ better protects mice from lethal DRV4 RABV infection in both pre- and post-exposure experiments compared to GASGAS. Finally, GASγGAS reduces post-infection neurological sequelae, compared to control, during mixed intracranial infection with DRV4. These data show IFNγ expression by a vaccine vector can enhance its safety while increasing its efficacy as pre- and post-exposure treatment. - Highlights: • IFNγ expression improves attenuated rabies virus safety and immunogenicity. • IFNγ expression is safer and more immunogenic than doubling glycoprotein expression. • Co-infection with IFNγ-expressing RABV prevents wild-type rabies virus lethality. • Vaccine safety and efficacy is additive for IFNγ and double glycoprotein expression.

  14. Nontyphoidal salmonella disease: Current status of vaccine research and development.

    Science.gov (United States)

    Tennant, Sharon M; MacLennan, Calman A; Simon, Raphael; Martin, Laura B; Khan, M Imran

    2016-06-01

    Among more than 2500 nontyphoidal Salmonella enterica (NTS) serovars, S. enterica serovar Typhimurium and S. enterica serovar Enteritidis account for approximately fifty percent of all human isolates of NTS reported globally. The global incidence of NTS gastroenteritis in 2010 was estimated to be 93 million cases, approximately 80 million of which were contracted via food-borne transmission. It is estimated that 155,000 deaths resulted from NTS in 2010. NTS also causes severe, extra-intestinal, invasive bacteremia, referred to as invasive nontyphoidal Salmonella (iNTS) disease. iNTS disease usually presents as a febrile illness, frequently without gastrointestinal symptoms, in both adults and children. Symptoms of iNTS are similar to malaria, often including fever (>90%) and splenomegaly (>40%). The underlying reasons for the high rates of iNTS disease in Africa are still being elucidated. Evidence from animal and human studies supports the feasibility of developing a safe and effective vaccine against iNTS. Both antibodies and complement can kill Salmonella species in vitro. Proof-of-principle studies in animal models have demonstrated efficacy for live attenuated and subunit vaccines that target the O-antigens, flagellin proteins, and other outer membrane proteins of serovars Typhimurium and Enteritidis. More recently, a novel delivery strategy for NTS vaccines has been developed: the Generalized Modules for Membrane Antigens (GMMA) technology which presents surface polysaccharides and outer membrane proteins in their native conformation. GMMA technology is self-adjuvanting, as it delivers multiple pathogen-associated molecular pattern molecules. GMMA may be particularly relevant for low- and middle-income countries as it has the potential for high immunologic potency at a low cost and involves a relatively simple production process without the need for complex conjugation. Several vaccines for the predominant NTS serovars Typhimurium and Enteritidis, are

  15. Generation and characterization of a cold-adapted attenuated live H3N2 subtype influenza virus vaccine candidate

    Institute of Scientific and Technical Information of China (English)

    AN Wen-qi; LIU Xiu-fan; WANG Xi-liang; YANG Peng-hui; DUAN Yue-qiang; LUO De-yan; TANG Chong; JIA Wei-hong; XING Li; SHI Xin-fu; ZHANG Yu-jing

    2009-01-01

    Background H3N2 subtype influenza A viruses have been identified in humans worldwide, raising concerns about their pandemic potential and prompting the development of candidate vaccines to protect humans against this subtype of influenza A virus. The aim of this study was to establish a system for rescuing of a cold-adapted high-yielding H3N2 subtype human influenza virus by reverse genetics. Methods In order to generate better and safer vaccine candidate viruses, a cold-adapted high yielding reassortant H3N2 influenza A virus was genetically constructed by reverse genetics and was designated as rgAA-H3N2. The rgAA-H3N2 virus contained HA and NA genes from an epidemic strain A/Wisconsin/67/2005 (H3N2) in a background of internal genes derived from the master donor viruses (MDV), cold-adapted (ca), temperature sensitive (te), live attenuated influenza virus strain A/Ann Arbor/6/60 (MDV-A). Results In this presentation, the virus HA titer of rgAA-H3N2 in the allantoic fluid from infected embryonated eggs was as high as 1:1024. A fluorescent focus assay (FFU) was performed 24-36 hours post-infection using a specific antibody and bright staining was used for determining the virus titer. The allantoic fluid containing the recovered influenza virus was analyzed in a hemagglutination inhibition (HI) test and the specific inhibition was found. Conclusion The results mentioned above demonstrated that cold-adapted, attenuated reassortant H3N2 subtype influenza A virus was successfully generated, which laid a good foundation for the further related research.

  16. Towards a Preventive Strategy for Toxoplasmosis: Current Trends, Challenges, and Future Perspectives for Vaccine Development.

    Science.gov (United States)

    Fereig, Ragab M; Nishikawa, Yoshifumi

    2016-01-01

    With its facultative ability to induce various types of infection in its hosts, Toxoplasma gondii remains a fascinating and enigmatic pathogen. As a parasite, despite its primitive unicellular structure, it possesses a highly sophisticated arsenal of invasive and defensive tools. Toxoplasmosis has gained widespread significance as a zoonotic disease capable of inducing severe illnesses in humans and drastic economic losses in the veterinary field. Although around a third of the world's population is infected with Toxoplasma gondii, immunocompromised people, pregnant women, and neonates are more vulnerable to the most severe forms of the disease. Hence, development of a preventive strategy is urgently needed to combat T. gondii infection in both humans and animals. Successful triggering of host immune responses and development of specific immune responses against the different strains and antigens of T. gondii has encouraged researchers to focus on vaccination as a feasible preventive control strategy against toxoplasmosis. In the last few years, vaccine development against T. gondii infections has seen great advances and achievements being made at the research level and, to a lesser extent, in veterinary applications. Currently, only one live attenuated vaccine is available for reducing abortions and fetal losses in pregnant ewes. Otherwise, researchers have investigated numerous classes of vaccine, including live attenuated, recombinant subunit, and vectored. In this chapter we discuss the most commonly investigated vaccines against toxoplasmosis, recombinant DNA and protein vaccines, with special focus on their methodologies and mechanisms of action. PMID:27076296

  17. Extended Safety and Efficacy Studies of the Attenuated Brucella Vaccine Candidates 16MΔvjbR and S19ΔvjbR in the Immunocompromised IRF-1−/− Mouse Model

    OpenAIRE

    Arenas-Gamboa, A. M.; Rice-Ficht, A C; Fan, Y.; Kahl-McDonagh, M. M.; Ficht, T A

    2012-01-01

    The global distribution of brucellosis and high incidence in certain areas of the world warrant the development of a safer and efficacious vaccine. For the past 10 years, we have focused our attention on the development of a safer, but still highly protective, live attenuated vaccine for human and animal use. We have demonstrated the safety and protective efficacy of the vaccine candidates 16MΔvjbR and S19ΔvjbR against homologous and heterologous challenge in multiple immunocompetent animal m...

  18. Eliciting neutralizing antibodies against the membrane proximal external region of HIV-1 Env by chimeric live attenuated influenza A virus vaccines.

    Science.gov (United States)

    Zang, Yang; Du, Dongchuan; Li, Na; Su, Weiheng; Liu, Xintao; Zhang, Yan; Nie, Jianhui; Wang, Youchun; Kong, Wei; Jiang, Chunlai

    2015-07-31

    Despite significant efforts directed toward research on HIV-1 vaccines, a truly effective immunogen has not been achieved. However, the broadly neutralizing antibodies (BnAbs) 2F5 and 4E10, targeting the highly conserved membrane proximal external region (MPER) of HIV-1, are two promising tools for vaccine development. Here we engrafted the MPER into the linker domain between the trimeric core structure and the transmembrane domain of influenza A virus HA2 to investigate the potential of such chimeric viruses to elicit HIV-1 neutralizing antibodies. In the context of proliferating attenuated influenza A viruses, these HIV-1 neutralizing antibody epitopes could be continuously expressed and mimicked their native conformation to induce humoral immune responses. While MPER-specific antibodies could be detected in serum of guinea pigs vaccinated with the chimeric viruses, they exhibited only weakly neutralizing activities. These antisera from vaccinated animals neutralized viruses of clades B and BC (tier 1), but not of clades AE (tier 1) and C (tier 2). These results suggest that influenza A virus can be used as a vehicle for displaying MPER and inducing BnAbs, but it provides limited protection against HIV-1 infection. In the future development of HIV-1 vaccines by rational design, a more effective live virus vector or multiple antigens should be chosen to facilitate the process of neutralizing antibody maturation. PMID:26126669

  19. Construction and evaluation of live attenuated myxoma virus vaccines with targeted virulence gene deletions.

    Science.gov (United States)

    Adams, Mathew M; van Leeuwen, Barbara H; Kerr, Peter J

    2008-10-29

    Three deletion mutant viruses were constructed as potential vaccines against myxomatosis using the naturally attenuated Uriarra strain of myxoma virus. The viruses had the M007 (encodes a secreted gamma-interferon receptor homologue), M010 (encodes an epidermal growth factor homologue) and M011 (encodes an inhibitor of apoptosis in T lymphocytes) genes insertionally inactivated as either DeltaM007, DeltaM010/M011 or DeltaM007/M010/M011. All three viruses induced high serum antibody titres. Rabbits immunized with these deletion mutants were protected from lethal challenge. However, immunization of adult rabbits with DeltaM007 or DeltaM010/M011 was associated with mild clinical signs that would make these viruses unacceptable as vaccines. The triple gene knock-out virus (DeltaM007/M010/M011) termed Ur-TKO was very well tolerated by adult and juvenile rabbits. The low pathogenicity of Ur-TKO was confirmed by pathogenesis studies in domestic and wild rabbits. PMID:18789367

  20. Characterization of attenuated Renibacterium salmoninarum strains and their use as live vaccines.

    Science.gov (United States)

    Daly, J G; Griffiths, S G; Kew, A K; Moore, A R; Olivier, G

    2001-03-01

    Two nutritionally mutant strains of Renibacterium salmoninarum (Rs) were isolated that grew on tryticase soy agar (Rs TSA1) or brain heart infusion agar (Rs BHI1). These 2 strains could be continuously cultured on these media, whereas typical R. salmoninarum would only grow on KDM-2 agar. We determined no other phenotypic difference that could be used to distinguish them from wild-type R. salmoninarum. Both strains were found to be avirulent when 5 x 10(6) bacteria were intraperitoneally (i.p.) injected into Atlantic salmon. Rs TSA1, Rs BHI1, and Rs MT-239 (a R. salmoninarum strain previously shown to be attenuated) were tested as live vaccines in 2 separate trials. The best protection was seen with Rs TSA1. Vaccinated Atlantic salmon had relative percent survival (RPS) of 50 at 74 d post-challenge in Trial 1 and 76 at 60 d post-challenge in Trial 2. In both trials, 100% of the control salmon died from bacterial kidney disease (BKD) (within 40 d for Trial 1 and 50 d for Trial 2) after i.p. challenge with 5 x 10(6) live cells of the virulent isolate Rs Margaree. PMID:11324812

  1. Antibody recognition of the dengue virus proteome and implications for development of vaccines.

    Science.gov (United States)

    Fernandez, Stefan; Cisney, Emily D; Tikhonov, Alexander P; Schweitzer, Barry; Putnak, Robert J; Simmons, Monika; Ulrich, Robert G

    2011-04-01

    Dengue is a mosquito-borne infection caused by four distinct serotypes of dengue virus, each appearing cyclically in the tropics and subtropics along the equator. Although vaccines are currently under development, none are available to the general population. One of the main impediments to the successful advancement of these vaccines is the lack of well-defined immune correlates of protection. Here, we describe a protein microarray approach for measuring antibody responses to the complete viral proteome comprised of the structural (capsid, membrane, and envelope) and nonstructural (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5) components of all four dengue virus serotypes (1 to 4). We examined rhesus macaques vaccinated with tetravalent vaccines consisting of live-attenuated virus (LAV) or purified inactivated virus (PIV), followed by boosting with LAV and challenging with wild-type dengue virus. We detected temporal increases in antibodies against envelope proteins in response to either vaccine, while only the PIV/LAV vaccination strategy resulted in anticapsid antibodies. In contrast to results from vaccination, naïve macaques challenged with wild-type viruses of each serotype demonstrated a balanced response to nonstructural and structural components, including responses against the membrane protein. Our results demonstrate discriminating details concerning the nature of antibody responses to dengue virus at the proteomic level and suggest the usefulness of this information for vaccine development. PMID:21270280

  2. 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.; Rontved, C.M.; Dalgaard, T.S.; Bumstead, N.; Jørgensen, Poul Henrik

    2002-01-01

    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...... weight, relative weights of the bursa and the spleen, percentage and relative number of MHC II molecules on MHC II-positive lymphocytes, percentage and relative number of CD4 molecules on CD4-positive lymphocytes, and the specific antibody response all differed significantly among lines. Line 1, with Red...

  3. Innocuity of a commercial live attenuated vaccine for epizootic hemorrhagic disease virus serotype 2 in late-term pregnant cows.

    Science.gov (United States)

    Spedicato, Massimo; Carmine, Irene; Teodori, Liana; Leone, Alessandra; Portanti, Ottavio; Marini, Valeria; Pisciella, Maura; Lorusso, Alessio; Savini, Giovanni

    2016-03-14

    Epizootic hemorrhagic disease (EHD) is an arthropod-borne infectious viral disease sustained by the epizootic hemorrhagic disease virus (EHDV). The only commercially available and currently used vaccines are manufactured for EHDV-2 in Japan, either live or inactivated vaccines. In this study we tested the innocuity for fetuses of the live attenuated EHDV-2 vaccine in five late-term pregnant cows. Whole blood and serum samples were collected from dams and screened for the presence of EHDV-2 RNA, infectious virus and antibodies. After calving, whole blood and serum samples collected from calves, before and after colostrum intake, were also tested for antibodies and for virus detection. In dams, neither fever nor clinical signs were observed. All of them seroconverted and a strong humoral response was detected throughout the sampling period. All blood samples tested negative for EHDV-2 except for one sample collected from a dam 11 days post-vaccination which tested positive at virus isolation at the third cell passage following two rounds of blind passages. Although they had free access to colostrum, calves tested serologically negative for EHDV-2 during the entire course of the experiment. Overall, the tested live attenuated vaccine can be safely administered to late-term pregnant cows as it was not demonstrated to cross the placental barrier. The safety of the live-attenuated vaccine is further confirmed by the emergence of Ibaraki virus in 2013 in Japan which is apparently not related to the spread of the vaccine strain currently used in Japan. PMID:26876438

  4. 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

    2016-05-01

    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. PMID:27060051

  5. Longitudinal study to assess the safety and efficacy of a live-attenuated SHIV vaccine in long term immunized rhesus macaques

    International Nuclear Information System (INIS)

    Live-attenuated viruses derived from SIV and SHIV have provided the most consistent protection against challenge with pathogenic viruses, but concerns regarding their long-term safety and efficacy have hampered their clinical usefulness. We report a longitudinal study in which we evaluated the long-term safety and efficacy of ΔvpuSHIVPPC, a live virus vaccine derived from SHIVPPC. Macaques were administered two inoculations of ΔvpuSHIVPPC, three years apart, and followed for eight years. None of the five vaccinated macaques developed an AIDS-like disease from the vaccine. At eight years, macaques were challenged with pathogenic SIV and SHIV. None of the four macaques with detectable cellular-mediated immunity prior to challenge had detectable viral RNA in the plasma. This study demonstrates that multiple inoculations of a live vaccine virus can be used safely and can significantly extend the efficacy of the vaccine, as compared to a single inoculation, which is efficacious for approximately three years

  6. Administration Time Between Seasonal Live-Attenuated Influenza Vaccine and Trivalent Influenza Vaccine During the “Stop Flu at School” Campaign— Hawaii, 2009

    Science.gov (United States)

    He, Hua H.; Park, Sarah Y.

    2014-01-01

    Objectives We determined whether the administration time differed between seasonal intranasal live-attenuated influenza vaccine (LAIV) and seasonal injectable trivalent inactivated influenza vaccine (TIV) during Hawaii's 2009 school-located influenza vaccination clinics. This information is useful for public health response and allows further investigation into possible differences between the two vaccines. Methods We conducted a prospective cohort study in 15 public schools to determine mean times to administer LAIV and TIV to students. We performed group analyses to control for various clinic characteristics and conducted a stratified, weighted analysis. Results A total of 4,701 students were enrolled in the study, and administration time was obtained for 3,869 (82%) students (1,492 [39%] LAIV and 2,377 [61%] TIV). The mean administration time for LAIV was 62 seconds and for TIV was 90 seconds, a difference of 28 seconds (p<0.01). This finding remained significant in the stratified analysis. Conclusions Although results indicated that both LAIV and TIV can be administered rapidly among school-aged populations, LAIV was faster to administer. This finding, in addition to the greater immunogenicity of LAIV compared with TIV among children, may be an important consideration for public health administrators in planning school-located mass vaccination clinics and encouraging patient acceptance of this vaccine. PMID:24791020

  7. Rotavirus vaccines: an overview.

    OpenAIRE

    Midthun, K; Kapikian, A Z

    1996-01-01

    Rotavirus vaccine development has focused on the delivery of live attenuated rotavirus strains by the oral route. The initial "Jennerian" approach involving bovine (RIT4237, WC3) or rhesus (RRV) rotavirus vaccine candidates showed that these vaccines were safe, well tolerated, and immunogenic but induced highly variable rates of protection against rotavirus diarrhea. The goal of a rotavirus vaccine is to prevent severe illness that can lead to dehydration in infants and young children in both...

  8. Brugia malayi: vaccination of jirds with /sup 60/cobalt-attenuated infective stage larvae protects against homologous challenge

    Energy Technology Data Exchange (ETDEWEB)

    Yates, J.A.; Higashi, G.I.

    1985-11-01

    Vaccination of inbred jirds (Meriones unguiculatus) with /sup 60/cobalt radiation-attenuated Brugia malayi infective stage larvae (L3) protected against homologous challenge given either subcutaneously (sc) or by the intraperitoneal (ip) route. Groups of jirds vaccinated once sc with 75, 15 Krad L3 showed from 69% to 91% reduction in recovered worms after ip challenge infection compared to infection in non-vaccinated control jirds, while 75% reduction in mean worm burden was seen in jirds receiving sc challenge infection. A single sc vaccination with 75, 10 or 20 Krad L3 produced no protection (10 Krad) and 64% reduction in recovered worms (20 Krad). Therefore the 15 Krad dose appeared to be best. A marked increase in anti-B. malayi antibody in vaccinated jirds was seen (by ELISA) immediately after challenge infection and an immunofluorescence assay showed that L3 incubated in serum from vaccinated jirds were completely and uniformly covered with specific antibody. Eosinophil-rich granulomas containing dead and moribund L3 were recovered from vaccinated jirds. This model of protective immunity in a Brugia-susceptible small rodent may provide a useful system for identification of molecularly defined filarial-protective immunogens.

  9. Protective efficacy of a live attenuated Mycoplasma hyopneumoniae vaccine with an ISCOM-matrix adjuvant in pigs.

    Science.gov (United States)

    Xiong, Qiyan; Wei, Yanna; Feng, Zhixin; Gan, Yuan; Liu, Zhanjun; Liu, Maojun; Bai, Fangfang; Shao, Guoqing

    2014-02-01

    An attenuated Mycoplasma hyopneumoniae vaccine that requires intrathoracic administration is commercially available for use against mycoplasmal pneumonia in China. Given the limitations of such a route of administration, this study was undertaken to assess the capacity of an ISCOM-matrix adjuvant to enhance immunogenicity following intramuscular use. Immune responses in pigs following vaccination and subsequent intra-tracheal bacterial inoculation were examined using lymphocyte proliferation, serology and mucosal IgA in both nasal and saliva swabs. Vaccination induced clear lymphocyte proliferation, but only slight serum antibody responses although these were significantly increased following experimental infection. Mucosal IgA was not detected in either nasal or salivary secretions. Following bacterial challenge, animals vaccinated with the adjuvant-containing live vaccine exhibited less severe pulmonary lesions (median score 3.67) than unvaccinated pigs (median score 13.58). The degree of ciliary loss on the respiratory tract surface was reduced in vaccinated pigs compared with experimentally infected controls. The findings indicated that the adjuvant vaccine administered IM provided protection against experimentally induced mycoplasmal pneumonia and could have commercial potential. PMID:24314715

  10. 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.

  11. HIV Vaccine Development: Strategies for Preclinical and Clinical Investigation

    OpenAIRE

    Shapiro, Stuart Z.

    2013-01-01

    This article discusses HIV vaccine discovery and candidate vaccine testing in the context of current realities of funding and clinical trial practice. Lacking perfect animal models for testing candidate HIV vaccines, clinical investigators have proposed a strategy of iterative exploratory clinical trials in the model of cancer chemotherapy development. Problems with the appropriateness of this model to HIV vaccine development are discussed. Also, the future feasibility of this strategy in the...

  12. Promising Rabies Vaccine for Postexposure Prophylaxis in Developing Countries, a Purified Vero Cell Vaccine Produced in China▿

    OpenAIRE

    Wang, Chuanlin; Zhang, Xiaowei; Song, Qingkun; Tang, Kun

    2010-01-01

    We evaluated the immunogenicity, safety, and antibody persistence of a Vero cell rabies vaccine manufactured in China, compared with those of Verorab. Adequate titers of antibody were observed for the two vaccines. ChengDa rabies vaccine could be a promising alternative vaccine for many developing countries which cannot afford expensive rabies vaccines.

  13. Varicella zoster vaccines and their implications for development of HSV vaccines

    Energy Technology Data Exchange (ETDEWEB)

    Gershon, Anne A., E-mail: aag1@columbia.edu [Department of Pediatrics, Columbia University College of Physicians and Surgeons, 620W. 168th Street, NY, NY 10032 (United States)

    2013-01-05

    Live attenuated vaccines to prevent varicella and zoster have been available in the US for the past 17 years, with a resultant dramatic decrease in varicella incidence and a predicted future decrease in the incidence of zoster. The pathogenesis and immune responses to varicella zoster virus (VZV) as well as the safety and effectiveness of VZV vaccines are reviewed. The lack of sterilizing immunity provided by VZV vaccines has not prevented them from being safe and effective. Virological and pathological information concerning parallels and differences between VZV and herpes simplex virus (HSV) are highlighted. Although VZV and HSV are distinct pathogens, they appear to have similarities in target organs and immunity that provide an expectation of a high likelihood for the success of vaccination against HSV, and predicted to be similar to that of VZV.

  14. Varicella zoster vaccines and their implications for development of HSV vaccines

    International Nuclear Information System (INIS)

    Live attenuated vaccines to prevent varicella and zoster have been available in the US for the past 17 years, with a resultant dramatic decrease in varicella incidence and a predicted future decrease in the incidence of zoster. The pathogenesis and immune responses to varicella zoster virus (VZV) as well as the safety and effectiveness of VZV vaccines are reviewed. The lack of sterilizing immunity provided by VZV vaccines has not prevented them from being safe and effective. Virological and pathological information concerning parallels and differences between VZV and herpes simplex virus (HSV) are highlighted. Although VZV and HSV are distinct pathogens, they appear to have similarities in target organs and immunity that provide an expectation of a high likelihood for the success of vaccination against HSV, and predicted to be similar to that of VZV.

  15. Early biodistribution and persistence of a protective live attenuated SIV vaccine elicits localised innate responses in multiple lymphoid tissues.

    Directory of Open Access Journals (Sweden)

    Deborah Ferguson

    Full Text Available Vaccination of Mauritian cynomolgus macaques with the attenuated nef-truncated C8 variant of SIVmac251/32H (SIVmacC8 induces early, potent protection against pathogenic, heterologous challenge before the maturation of cognate immunity. To identify processes that contribute to early protection in this model the pathogenesis, anatomical distribution and viral vaccine kinetics were determined in relation to localised innate responses triggered by vaccination. The early biodistribution of SIVmacC8 was defined by rapid, widespread dissemination amongst multiple lymphoid tissues, detectable after 3 days. Cell-associated viral RNA dynamics identified mesenteric lymph nodes (MLN and spleen, as well as the gut mucosae, as early major contributors of systemic virus burden. Rapid, localised infection was populated by discrete foci of persisting virus-infected cells. Localised productive infection triggered a broad innate response, with type-1 interferon sensitive IRF-7, STAT-1, TRIM5α and ApoBEC3G genes all upregulated during the acute phase but induction did not prevent viral persistence. Profound changes in vaccine-induced cell-surface markers of immune activation were detected on macrophages, B-cells and dendritic cells (DC-SIGN, S-100, CD40, CD11c, CD123 and CD86. Notably, high DC-SIGN and S100 staining for follicular and interdigitating DCs respectively, in MLN and spleen were detected by 3 days, persisting 20 weeks post-vaccination. Although not formally evaluated, the early biodistribution of SIVmacC8 simultaneously targets multiple lymphoid tissues to induce strong innate immune responses coincident at the same sites critical for early protection from wild-type viruses. HIV vaccines which stimulate appropriate innate, as well as adaptive responses, akin to those generated by live attenuated SIV vaccines, may prove the most efficacious.

  16. Vaccination Against Tuberculosis With Whole-Cell Mycobacterial Vaccines.

    Science.gov (United States)

    Scriba, Thomas J; Kaufmann, Stefan H E; Henri Lambert, Paul; Sanicas, Melvin; Martin, Carlos; Neyrolles, Olivier

    2016-09-01

    Live attenuated and killed whole-cell vaccines (WCVs) offer promising vaccination strategies against tuberculosis. A number of WCV candidates, based on recombinant bacillus Calmette-Guerin (BCG), attenuated Mycobacterium tuberculosis, or related mycobacterial species are in various stages of preclinical or clinical development. In this review, we discuss the vaccine candidates and key factors shaping the development pathway for live and killed WCVs and provide an update on progress. PMID:27247343

  17. Vaccination of pigs against Aujeszky's disease by the intradermal route using live attenuated and inactivated virus vaccines.

    Science.gov (United States)

    Vannier, P; Cariolet, R

    1989-09-01

    A study was undertaken of the protection induced by inactivated and live Aujeszky's disease virus vaccines. The vaccines were administered using a special device which, without the use of a needle, delivered the preparation intradermally. The trials were performed on 88 pigs which were vaccinated at the beginning of the fattening period both in experimental conditions and in pig herds. All the pigs were challenged at the end of the fattening period in isolation units. The results obtained were compared with those obtained using the same vaccines injected intramuscularly. It was shown that vaccination via the intradermal route induced good protection in the vaccinated animals and was similar to that conferred by live virus vaccine injected intramuscularly. The results, with the inactivated virus vaccine, were not so good when it was injected via the intradermal route. Studies with intradermal vaccination showed no local lesion or very small nodules strictly localized to the dermis. The results also confirmed that the effects of challenge exposure depended on the health status of animals prior to infection and show the necessity to use a synthetic value (delta G) to interpret the data and mainly to compare the results objectively. In fattening pigs this vaccination procedure is attractive because (i) less animal constraint is needed than would be for intramuscular injections, (ii) injection can be checked by the presence of a visible papula at the site of inoculation and, (iii) pigs can be vaccinated in the ham while they are feeding. Injection without a needle also contributes to avoiding bacterial contamination under practical farm conditions of vaccination. PMID:2554623

  18. Vaxjo: A Web-Based Vaccine Adjuvant Database and Its Application for Analysis of Vaccine Adjuvants and Their Uses in Vaccine Development

    Directory of Open Access Journals (Sweden)

    Samantha Sayers

    2012-01-01

    Full Text Available Vaccine adjuvants are compounds that enhance host immune responses to co-administered antigens in vaccines. Vaxjo is a web-based central database and analysis system that curates, stores, and analyzes vaccine adjuvants and their usages in vaccine development. Basic information of a vaccine adjuvant stored in Vaxjo includes adjuvant name, components, structure, appearance, storage, preparation, function, safety, and vaccines that use this adjuvant. Reliable references are curated and cited. Bioinformatics scripts are developed and used to link vaccine adjuvants to different adjuvanted vaccines stored in the general VIOLIN vaccine database. Presently, 103 vaccine adjuvants have been curated in Vaxjo. Among these adjuvants, 98 have been used in 384 vaccines stored in VIOLIN against over 81 pathogens, cancers, or allergies. All these vaccine adjuvants are categorized and analyzed based on adjuvant types, pathogens used, and vaccine types. As a use case study of vaccine adjuvants in infectious disease vaccines, the adjuvants used in Brucella vaccines are specifically analyzed. A user-friendly web query and visualization interface is developed for interactive vaccine adjuvant search. To support data exchange, the information of vaccine adjuvants is stored in the Vaccine Ontology (VO in the Web Ontology Language (OWL format.

  19. Accelerating Next Generation Vaccine Development for Global Disease Prevention

    OpenAIRE

    Koff, Wayne C.; Dennis R Burton; R.Johnson, Philip; Walker, Bruce D; King, Charles R.; Nabel, Gary J.; Ahmed, Rafi; Bhan, Maharaj Kishan; Plotkin, Stanley A.

    2013-01-01

    Vaccines are among the greatest successes in the history of public health. However, past strategies for vaccine development are unlikely to succeed in the future against major global diseases such as AIDS, TB, and malaria. For such diseases, the correlates of protection are poorly defined and the pathogens evade immune detection and/or exhibit extensive genetic variability. Recent advances have heralded in a new era of vaccine discovery. However, translation of these advances into vaccines re...

  20. Global Vaccine and Immunization Research Forum: Opportunities and challenges in vaccine discovery, development, and delivery.

    Science.gov (United States)

    Ford, Andrew Q; Touchette, Nancy; Hall, B Fenton; Hwang, Angela; Hombach, Joachim

    2016-03-18

    The World Health Organization, the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, and the Bill & Melinda Gates Foundation convened the first Global Vaccine and Immunization Research Forum (GVIRF) in March 2014. This first GVIRF aimed to track recent progress of the Global Vaccine Action Plan research and development agenda, identify opportunities and challenges, promote partnerships in vaccine research, and facilitate the inclusion of all stakeholders in vaccine research and development. Leading scientists, vaccine developers, and public health officials from around the world discussed scientific and technical challenges in vaccine development, research to improve the impact of immunization, and regulatory issues. This report summarizes the discussions and conclusions from the forum participants. PMID:26626210

  1. Impact of BRICS' investment in vaccine development on the global vaccine market.

    Science.gov (United States)

    Kaddar, Miloud; Milstien, Julie; Schmitt, Sarah

    2014-06-01

    Brazil, the Russian Federation, India, China and South Africa--the countries known as BRICS--have made considerable progress in vaccine production, regulation and development over the past 20 years. In 1993, all five countries were producing vaccines but the processes used were outdated and non-standardized, there was little relevant research and there was negligible international recognition of the products. By 2014, all five countries had strong initiatives for the development of vaccine technology and had greatly improved their national regulatory capacity. South Africa was then the only BRICS country that was not completely producing vaccines. South Africa is now in the process of re-establishing its own vaccine production and passing beyond the stage of simply importing, formulating and filling vaccine bulks. Changes in the public sector's price per dose of selected vaccines, the global market share represented by products from specific manufacturers, and the attractiveness, for multinational companies, of partnership and investment opportunities in BRICS companies have all been analysed. The results indicate that the BRICS countries have had a major impact on vaccine price and availability, with much of that impact attributable to the output of Indian vaccine manufacturers. China is expected to have a greater impact soon, given the anticipated development of Chinese vaccine manufacturers in the near future. BRICS' accomplishments in the field of vaccine development are expected to reshape the global vaccine market and accelerate access to vaccines in the developing world. The challenge is to turn these expectations into strategic actions and practical outcomes. PMID:24940018

  2. WHO policy development processes for a new vaccine: case study of malaria vaccines

    OpenAIRE

    Cheyne James; Cárdenas Vicky; Milstien Julie; Brooks Alan

    2010-01-01

    Abstract Background Recommendations from the World Health Organization (WHO) are crucial to inform developing country decisions to use, or not, a new intervention. This article analysed the WHO policy development process to predict its course for a malaria vaccine. Methods The decision-making processes for one malaria intervention and four vaccines were classified through (1) consultations with staff and expert advisors to WHO's Global Malaria Programme (GMP) and Immunization, Vaccines and Bi...

  3. Virulence determinants of Salmonella Gallinarum biovar Pullorum identified by PCR signature-tagged mutagenesis and the spiC mutant as a candidate live attenuated vaccine.

    Science.gov (United States)

    Geng, Shizhong; Jiao, Xinan; Barrow, Paul; Pan, Zhiming; Chen, Xiang

    2014-01-31

    Salmonella Gallinarum biovar Pullorum (S. Gallinarum biovar Pullorum) is the causative agent of pullorum disease (PD) in chickens which results in considerable economic losses to the poultry industries in developing countries. PCR-Signature Tagged Mutagenesis was used to identify virulence determinants of S. Gallinarum biovar Pullorum and novel attenuated live vaccine candidates for use against this disease. A library of 1800 signature-tagged S. Gallinarum biovar Pullorum mutants was constructed and screened for virulence-associated genes in chickens. The attenuation of 10 mutants was confirmed by in vivo and in vitro competitive index (CI) studies. The transposons were found to be located in SPI-1 (2/10 mutants), SPI-2 (3/10), the virulence plasmid (1/10) and non-SPI genes (4/10). One highly attenuated spiC mutant persisted in spleen and liver for less than 10 days and induced high levels of circulating antibody and protective immunity against oral challenge in young broiler chickens. The spiC mutant is a potential new vaccine candidate for use with chickens against this disease. PMID:24355532

  4. [Rabies vaccines: Current status and prospects for development].

    Science.gov (United States)

    Starodubova, E S; Preobrazhenskaia, O V; Kuzmenko, Y V; Latanova, A A; Yarygina, E I; Karpov, V L

    2015-01-01

    Rabies is an infectious disease among humans and animals that remains incurable, despite its longstanding research history. The only way to prevent the disease is prompt treatment, including vaccination as an obligatory component and administration of antirabies immunoglobulin as a supplement. Since the first antirabies vaccination performed in the 19th century, a large number of different rabies vaccines have been developed. Progress in molecular biology and biotechnology enabled the development of effective and safe technologies of vaccine production. Currently, new-generation vaccines are being developed based on recombinant rabies virus strains or on the production of an individual recombinant rabies antigen-glycoprotein (G protein), either as a component of nonpathogenic viruses, or in plants, or in the form of DNA vaccines. In this review, the main modern trends in the development of rabies vaccines have been discussed. PMID:26299857

  5. Chikungunya virus vaccines: Current strategies and prospects for developing plant-made vaccines.

    Science.gov (United States)

    Salazar-González, Jorge A; Angulo, Carlos; Rosales-Mendoza, Sergio

    2015-07-17

    Chikungunya virus is an emerging pathogen initially found in East Africa and currently spread into the Indian Ocean Islands, many regions of South East Asia, and in the Americas. No licensed vaccines against this eminent pathogen are available and thus intensive research in this field is a priority. This review presents the current scenario on the developments of Chikungunya virus vaccines and identifies the use of genetic engineered plants to develop attractive vaccines. The possible avenues to develop plant-made vaccines with distinct antigenic designs and expression modalities are identified and discussed considering current trends in the field. PMID:26073010

  6. Vaxjo: A Web-Based Vaccine Adjuvant Database and Its Application for Analysis of Vaccine Adjuvants and Their Uses in Vaccine Development

    OpenAIRE

    Samantha Sayers; Guerlain Ulysse; Zuoshuang Xiang; Yongqun He

    2012-01-01

    Vaccine adjuvants are compounds that enhance host immune responses to co-administered antigens in vaccines. Vaxjo is a web-based central database and analysis system that curates, stores, and analyzes vaccine adjuvants and their usages in vaccine development. Basic information of a vaccine adjuvant stored in Vaxjo includes adjuvant name, components, structure, appearance, storage, preparation, function, safety, and vaccines that use this adjuvant. Reliable references are curated and cited. Bi...

  7. EFFECT OF VARIOUS STABILIZERS ON TITRE OF LYOPHILIZED LIVE-ATTENUATED PESTE DES PETITS RUMINANTS (PPR) VACCINE

    OpenAIRE

    M. ASIM, A. RASHID AND A. H. CHAUDHARY

    2008-01-01

    Lyophilization stabilizes the biological materials by using two overlapping drying procedure i.e. primary drying by sublimation of the ice crystal from frozen material and secondary drying or desorption by evaporation of the free water adsorbed into the dried product. Three different stabilizers i.e. lactalbumin hydrolysate-sucrose, Weybridge medium and lactalbumin hydrolysate-manitol were used to lyophilize the Peste des petits ruminants (PPR) vaccine. Titre of live-attenuated PPR cell cultu...

  8. Why the radiation-attenuated cercarial immunization studies failed to guide the road for an effective schistosomiasis vaccine: A review

    OpenAIRE

    Rashika El Ridi; Hatem Tallima

    2014-01-01

    Schistosomiasis is a debilitating parasitic disease caused by platyhelminthes of the genus Schistosoma, notably Schistosoma mansoni, Schistosoma haematobium, and Schistosoma japonicum. Pioneer researchers used radiation-attenuated (RA) schistosome larvae to immunize laboratory rodent and non-human primate hosts. Significant and reproducible reduction in challenge worm burden varying from 30% to 90% was achieved, providing a sound proof that vaccination against this infection is feasible. Exte...

  9. Immunoinformatics of Placental Malaria Vaccine Development

    DEFF Research Database (Denmark)

    Jessen, Leon Eyrich

    Malaria is an infectious disease caused by a protozoan parasite of the genus Plasmodium, which is transferred by female Anopheles mosquitos. WHO estimates that in 2012 there were 207 million cases of malaria, of which 627,000 were fatal. People living in malaria-endemic areas, gradually acquire...... immunity with multiple infections. Placental malaria (PM) is caused by P. falciparum sequestering in the placenta of pregnant women due to the presence of novel receptors in the placenta. An estimated 200,000 infants die a year as a result of PM. In 2004 the specific protein responsible for the...... and development in the field of placental malaria vaccine development....

  10. Pre- and post-exposure safety and efficacy of attenuated rabies virus vaccines are enhanced by their expression of IFNγ.

    Science.gov (United States)

    Barkhouse, Darryll A; Faber, Milosz; Hooper, D Craig

    2015-01-01

    Consistent with evidence of a strong correlation between interferon gamma (IFNγ) production and rabies virus (RABV) clearance from the CNS, we recently demonstrated that engineering a pathogenic RABV to express IFNγ highly attenuates the virus. Reasoning that IFNγ expression by RABV vaccines would enhance their safety and efficacy, we reverse-engineered two proven vaccine vectors, GAS and GASGAS, to express murine IFNγ. Mortality and morbidity were monitored during suckling mice infection, immunize/challenge experiments and mixed intracranial infections. We demonstrate that GASγ and GASγGAS are significantly attenuated in suckling mice compared to the GASGAS vaccine. GASγ better protects mice from lethal DRV4 RABV infection in both pre- and post-exposure experiments compared to GASGAS. Finally, GASγGAS reduces post-infection neurological sequelae, compared to control, during mixed intracranial infection with DRV4. These data show IFNγ expression by a vaccine vector can enhance its safety while increasing its efficacy as pre- and post-exposure treatment. PMID:25463615

  11. Guiding dengue vaccine development using knowledge gained from the success of the yellow fever vaccine.

    Science.gov (United States)

    Liang, Huabin; Lee, Min; Jin, Xia

    2016-01-01

    Flaviviruses comprise approximately 70 closely related RNA viruses. These include several mosquito-borne pathogens, such as yellow fever virus (YFV), dengue virus (DENV), and Japanese encephalitis virus (JEV), which can cause significant human diseases and thus are of great medical importance. Vaccines against both YFV and JEV have been used successfully in humans for decades; however, the development of a DENV vaccine has encountered considerable obstacles. Here, we review the protective immune responses elicited by the vaccine against YFV to provide some insights into the development of a protective DENV vaccine. PMID:26435066

  12. Study of the safety, immunogenicity and efficacy of attenuated and killed Leishmania (Leishmania major vaccines in a rhesus monkey (Macaca mulatta model of the human disease

    Directory of Open Access Journals (Sweden)

    VF Amaral

    2002-10-01

    Full Text Available We have compared the efficacy of two Leishmania (Leishmania major vaccines, one genetically attenuated (DHFR-TS deficient organisms, the other inactivated [autoclaved promastigotes (ALM with bacillus Calmete-Guérin (BCG], in protecting rhesus macaques (Macaca mulatta against infection with virulent L. (L. major. Positive antigen-specific recall proliferative response was observed in vaccinees (79% in attenuated parasite-vaccinated monkeys, versus 75% in ALM-plus-BCG-vaccinated animals, although none of these animals exhibited either augmented in vitro gamma interferon (IFN-g production or positive delayed-type hypersensitivity (DTH response to the leishmanin skin test prior to the challenge. Following challenge, there were significant differences in blastogenic responses (p < 0.05 between attenuated-vaccinated monkeys and naïve controls. In both vaccinated groups very low levels of antibody were found before challenge, which increased after infective challenge. Protective immunity did not follow vaccination, in that monkeys exhibited skin lesion at the site of challenge in all the groups. The most striking result was the lack of pathogenicity of the attenuated parasite, which persisted in infected animals for up to three months, but were incapable of causing disease under the conditions employed. We concluded that both vaccine protocols used in this study are safe in primates, but require further improvement for vaccine application.

  13. Requirements of New Vaccines against Novel Influenza Viruses

    OpenAIRE

    Kobayashi, Osamu

    2014-01-01

    The currently available influenza vaccines were developed in the 1930s through the 1960s using technologies that were state-of-the art for the times. Decades of advancement in virology and immunology have provided the tools for making better vaccines against influenza virus. Among young children, live attenuated vaccine had significantly better efficacy than inactivated vaccine. An evaluation of the risks and benefits indicates that live attenuated vaccine should be a highly effective, safe v...

  14. Protein carriers of conjugate vaccines: characteristics, development, and clinical trials.

    Science.gov (United States)

    Pichichero, Michael E

    2013-12-01

    The immunogenicity of polysaccharides as human vaccines was enhanced by coupling to protein carriers. Conjugation transformed the T cell-independent polysaccharide vaccines of the past to T cell-dependent antigenic vaccines that were much more immunogenic and launched a renaissance in vaccinology. This review discusses the conjugate vaccines for prevention of infections caused by Hemophilus influenzae type b, Streptococcus pneumoniae, and Neisseria meningitidis. Specifically, the characteristics of the proteins used in the construction of the vaccines including CRM, tetanus toxoid, diphtheria toxoid, Neisseria meningitidis outer membrane complex, and Hemophilus influenzae protein D are discussed. The studies that established differences among and key features of conjugate vaccines including immunologic memory induction, reduction of nasopharyngeal colonization and herd immunity, and antibody avidity and avidity maturation are presented. Studies of dose, schedule, response to boosters, of single protein carriers with single and multiple polysaccharides, of multiple protein carriers with multiple polysaccharides and conjugate vaccines administered concurrently with other vaccines are discussed along with undesirable consequences of conjugate vaccines. The clear benefits of conjugate vaccines in improving the protective responses of the immature immune systems of young infants and the senescent immune systems of the elderly have been made clear and opened the way to development of additional vaccines using this technology for future vaccine products. PMID:23955057

  15. Efficacy of HVT-IBD vector vaccine compared to attenuated live vaccine using in-ovo vaccination against a Korean very virulent IBDV in commercial broiler chickens.

    Science.gov (United States)

    Roh, J-H; Kang, M; Wei, B; Yoon, R-H; Seo, H-S; Bahng, J-Y; Kwon, J-T; Cha, S-Y; Jang, H-K

    2016-05-01

    The production performance, efficacy, and safety of two types of vaccines for infectious bursal disease virus (IBDV) were compared with in-ovo vaccination of Cobb 500 broiler chickens for gross and microscopic examination of the bursa of Fabricius, bursa/body weight (b/B) ratio, flow cytometry, and serologic response to Newcastle disease virus (NDV) vaccination. One vaccine was a recombinant HVT-IBD vector vaccine (HVT as for herpesvirus of turkeys) and the other was an intermediate plus live IBDV vaccine. A significant difference was detected at 21 d. Eight of 10 chickens that received the IBDV live vaccine had severe bursal lesions and a relatively low b/B ratio of 0.95, and an inhibited NDV vaccine response. On the other hand, the HVT-IBD vector vaccine resulted in mild bursal lesions and a b/B ratio of 1.89. Therefore, the live vaccine had lower safety than that of the HVT-IBD vector vaccine. To determine the protective efficacy, chickens were intraocularly challenged at 24 d. Eight of 10 chickens in the IBDV live vaccination group showed gross and histological lesions characterized by hemorrhage, cyst formation, lymphocytic depletion, and a decreased b/B ratio. In contrast, the HVT-IBD vector vaccinated chickens showed mild gross and histological lesions in three of 10 chickens with a b/B ratio of 1.36, which was similar to that of the unchallenged controls. Vaccinated chickens showed a significant increase in IBDV antibody titers, regardless of the type of vaccine used. In addition, significantly better broiler flock performance was observed with the HVT-IBD vector vaccine compared to that of the live vaccine. Our results revealed that the HVT-IBD vector vaccine could be used as an alternative vaccine to increase efficacy, and to have an improved safety profile compared with the IBDV live vaccine using in-ovo vaccination against the Korean very virulent IBDV in commercial broiler chickens. PMID:26944964

  16. Development of Novel Vaccines against Enterovirus-71

    OpenAIRE

    Pinn Tsin Isabel Yee; Chit Laa Poh

    2015-01-01

    The hand, foot and mouth disease is caused by a group of Enteroviruses such as Enterovirus 71 (EV-A71) and Coxsackievirus CV-A5, CV-A8, and CV-A16. Mild symptoms of EV-A71 infection in children range from high fever, vomiting, rashes and ulcers in mouth but can produce more severe symptoms such as brainstem and cerebellar encephalitis, leading up to cardiopulmonary failure and death. The lack of vaccines and antiviral drugs against EV-A71 highlights the urgency of developing preventive and tr...

  17. Construction of Prophylactic Human Papillomavirus Type 16 L1 Capsid Protein Vaccine Delivered by Live Attenuated Shigella flexneri Strain sh42

    Institute of Scientific and Technical Information of China (English)

    Xiao-Feng YANG; Xin-Zhong QU; Kai WANG; Jin ZHENG; Lü-Sheng SI; Xiao-Ping DONG; Yi-Li WANG

    2005-01-01

    To express human papillomavirus (HPV) L1 capsid protein in the recombinant strain of Shigella and study the potential of a live attenuated Shigella-based HPV prophylactic vaccine in preventing HPV infection, the icsA/virG fragment of Shigella-based prokaryotic expression plasmid pHS3199 was constructed.HPV type 16 L 1 (HPV 16L 1) gene was inserted into plasmid pHS 3199 to form the pHS3199-HPV 16L1construct, and pHS3199-HPV16L1 was electroporated into a live attenuated Shigella strain sh42. Western blotting analysis showed that HPV 16L1 could be expressed stably in the recombinant strain sh42-HPV 16L1.Sereny test results were negative, which showed that the sh42-HPV16L1 lost virulence. However, the attenuated recombinant strain partially maintained the invasive property as indicated by the HeLa cell infection assay. Specific IgG, IgA antibody against HPV16L1 virus-like particles (VLPs) were detected in the sera,intestinal lavage and vaginal lavage from animals immunized by sh42-HPV 16L 1. The number of antibodysecreting cells in the spleen and draining lymph nodes were increased significantly compared with the control group. Sera from immunized animals inhibited murine hemagglutination induced by HPV16L1 VLPs, which indicated that the candidate vaccine could stimulate an efficient immune response in guinea pig's mucosal sites. This may be an effective strategy for the development of an HPV prophylactic oral vaccine.

  18. Consensus on the Development of Vaccines against Naturally Acquired Melioidosis

    OpenAIRE

    Limmathurotsakul, Direk; Funnell, Simon G.P.; Torres, Alfredo G.; Morici, Lisa A.; Brett, Paul J.; Dunachie, Susanna; Atkins, Timothy; Altmann, Daniel M.; Bancroft, Gregory; Peacock, Sharon J.; ,

    2015-01-01

    Several candidates for a vaccine against Burkholderia pseudomallei, the causal bacterium of melioidosis, have been developed, and a rational approach is now needed to select and advance candidates for testing in relevant nonhuman primate models and in human clinical trials. Development of such a vaccine was the topic of a meeting in the United Kingdom in March 2014 attended by international candidate vaccine developers, researchers, and government health officials. The focus of the meeting wa...

  19. Nonclinical Development of BCG Replacement Vaccine Candidates

    OpenAIRE

    Bernd Eisele; Martin Gengenbacher; Reginald Kidd; David McCown; Sheldon Morris; Steven Derrick; David Hokey; Dominick Laddy; Rosemary Chang; Megan Fitzpatrick; Leander Grode; Kamalakannan Velmurugan; Stefan H. E. Kaufmann; John Fulkerson; Brennan, Michael J.

    2013-01-01

    The failure of current Mycobacterium bovis bacille Calmette–Guérin (BCG) vaccines, given to neonates to protect against adult tuberculosis and the risk of using these live vaccines in HIV-infected infants, has emphasized the need for generating new, more efficacious and safer replacement vaccines. With the availability of genetic techniques for constructing recombinant BCG (rBCG) strains containing well-defined gene deletions or insertions, new vaccine candidates are under evaluation at both ...

  20. Protection of Macaques against AIDS with a Live Attenuated SHIV Vaccine is of Finite Duration

    OpenAIRE

    Kumar, Anil; Liu, Zhenqian; Sheffer, Darlene; Smith, Marilyn; Singh, Dinesh K.; Buch, Shilpa; Narayan, Opendra

    2007-01-01

    Using background data that live vaccines against several viral pathogens are effective in inducing life-long protection against disease, we undertook studies in macaques to determine the duration of protection that two live SHIV vaccines could induce against AIDS. Earlier studies had established that macaques immunized once with a live vaccine and challenged 6 months later were protected, and that other macaques given two sequential inoculations of live vaccines were protected for at least on...

  1. Genome sequence comparison of two United States live attenuated vaccines of infectious laryngotracheitis virus (ILTV).

    Science.gov (United States)

    Chandra, Yohanna Gita; Lee, Jeongyoon; Kong, Byung-Whi

    2012-06-01

    This study was conducted to identify unique nucleotide differences in two U.S. chicken embryo origin (CEO) vaccines [LT Blen (GenBank accession: JQ083493) designated as vaccine 1; Laryngo-Vac(®) (GenBank accession: JQ083494) designated as vaccine 2] of infectious laryngotracheitis virus (ILTV) genomes compared to an Australian Serva vaccine reference ILTV genome sequence [Gallid herpesvirus 1 (GaHV-1); GenBank accession number: HQ630064]. Genomes of the two vaccine ILTV strains were sequenced using Illumina Genome Analyzer 2X of 36 cycles of single-end reads. Results revealed that few nucleotide differences (23 in vaccine 1; 31 in vaccine 2) were found and indicate that the US CEO strains are practically identical to the Australian Serva CEO strain, which is a European-origin vaccine. The sequence differences demonstrated the spectrum of variability among vaccine strains. Only eight amino acid differences were found in ILTV proteins including UL54, UL27, UL28, UL20, UL1, ICP4, and US8 in vaccine 1. Similarly, in vaccine 2, eight amino acid differences were found in UL54, UL27, UL28, UL36, UL1, ICP4, US10, and US8. Further comparison of US CEO vaccines to several ILTV genome sequences revealed that US CEO vaccines are genetically close to both the Serva vaccine and 63140/C/08/BR (GenBank accession: HM188407) and are distinct from the two Australian-origin CEO vaccines, SA2 (GenBank accession: JN596962) and A20 (GenBank accession: JN596963), which showed close similarity to each other. These data demonstrate the potential of high-throughput sequencing technology to yield insight into the sequence variation of different ILTV strains. This information can be used to discriminate between vaccine ILTV strains and further, to identify newly emerging mutant strains of field isolates. PMID:22382591

  2. The safety and efficacy of immunizing foxes (Vulpes vulpes) using bait containing attenuated rabies virus vaccine.

    OpenAIRE

    Black, J. G.; Lawson, K. F.

    1980-01-01

    Foxes given ERA rabies vaccine baits were challenged at one, six, 12 and 24 months later and showed a resistance to challenge in 80%, 78%, 60% and 44% of individuals respectively. All animals showing seroconversion following vaccination, resisted challenge at 24 months, suggesting that successful vaccination by the oral route could confer a relatively long term duration of immunity. The trials showed that fox pups did not immunize as easily as adult foxes using ERA rabies vaccine baits. Back-...

  3. A novel method for synthetic vaccine construction based on protein assembly

    OpenAIRE

    Zhida Liu; Hang Zhou; Wenjun Wang; Wenjie Tan; Yang-Xin Fu; Mingzhao Zhu

    2014-01-01

    In the history of vaccine development, the synthetic vaccine is a milestone that is in stark contrast with traditional vaccines based on live-attenuated or inactivated microorganisms. Synthetic vaccines not only are safer than attenuated or inactivated microorganisms but also provide the opportunity for vaccine design for specific purposes. The first generation of synthetic vaccines has been largely based on DNA recombination technology and genetic manipulation. This de novo generation is occ...

  4. Large animal models for vaccine development and testing.

    Science.gov (United States)

    Gerdts, Volker; Wilson, Heather L; Meurens, Francois; van Drunen Littel-van den Hurk, Sylvia; Wilson, Don; Walker, Stewart; Wheler, Colette; Townsend, Hugh; Potter, Andrew A

    2015-01-01

    The development of human vaccines continues to rely on the use of animals for research. Regulatory authorities require novel vaccine candidates to undergo preclinical assessment in animal models before being permitted to enter the clinical phase in human subjects. Substantial progress has been made in recent years in reducing and replacing the number of animals used for preclinical vaccine research through the use of bioinformatics and computational biology to design new vaccine candidates. However, the ultimate goal of a new vaccine is to instruct the immune system to elicit an effective immune response against the pathogen of interest, and no alternatives to live animal use currently exist for evaluation of this response. Studies identifying the mechanisms of immune protection; determining the optimal route and formulation of vaccines; establishing the duration and onset of immunity, as well as the safety and efficacy of new vaccines, must be performed in a living system. Importantly, no single animal model provides all the information required for advancing a new vaccine through the preclinical stage, and research over the last two decades has highlighted that large animals more accurately predict vaccine outcome in humans than do other models. Here we review the advantages and disadvantages of large animal models for human vaccine development and demonstrate that much of the success in bringing a new vaccine to market depends on choosing the most appropriate animal model for preclinical testing. PMID:25991698

  5. CD8 Knockout Mice Are Protected from Challenge by Vaccination with WR201, a Live Attenuated Mutant of Brucella melitensis

    Directory of Open Access Journals (Sweden)

    Samuel L. Yingst

    2013-01-01

    Full Text Available CD8+ T cells have been reported to play an important role in defense against B. abortus infection in mouse models. In the present report, we use CD8 knockout mice to further elucidate the role of these cells in protection from B. melitensis infection. Mice were immunized orally by administration of B. melitensis WR201, a purine auxotrophic attenuated vaccine strain, then challenged intranasally with B. melitensis 16M. In some experiments, persistence of WR201 in the spleens of CD8 knockout mice was slightly longer than that in the spleens of normal mice. However, development of anti-LPS serum antibody, antigen-induced production of γ-interferon (IFN-γ by immune splenic lymphocytes, protection against intranasal challenge, and recovery of nonimmunized animals from intranasal challenge were similar between normal and knockout animals. Further, primary Brucella infection was not exacerbated in perforin knockout and Fas-deficient mice and these animals’ anti-Brucella immune responses were indistinguishable from those of normal mice. These results indicate that CD8+ T cells do not play an essential role as either cytotoxic cells or IFN-γ producers, yet they do participate in a specific immune response to immunization and challenge in this murine model of B. melitensis infection.

  6. Porcine circovirus type 2 (PCV2 infection decreases the efficacy of an attenuated classical swine fever virus (CSFV vaccine

    Directory of Open Access Journals (Sweden)

    Huang Yu-Liang

    2011-12-01

    Full Text Available Abstract The Lapinized Philippines Coronel (LPC vaccine, an attenuated strain of classical swine fever virus (CSFV, is an important tool for the prevention and control of CSFV infection and is widely and routinely used in most CSF endemic areas, including Taiwan. The aim of this study was to investigate whether PCV2 infection affects the efficacy of the LPC vaccine. Eighteen 6-week-old, cesarean-derived and colostrum-deprived (CDCD, crossbred pigs were randomly assigned to four groups. A total of 105.3 TCID50 of PCV2 was experimentally inoculated into pigs through both intranasal and intramuscular routes at 0 days post-inoculation (dpi followed by LPC vaccination 12 days later. All the animals were challenged with wild-type CSFV (ALD stain at 27 dpi and euthanized at 45 dpi. Following CSFV challenge, the LPC-vaccinated pigs pre-inoculated with PCV2 showed transient fever, viremia, and viral shedding in the saliva and feces. The number of IgM+, CD4+CD8-CD25+, CD4+CD8+CD25+, and CD4-CD8+CD25+ lymphocyte subsets and the level of neutralizing antibodies against CSFV were significantly higher in the animals with LPC vaccination alone than in the pigs with PCV2 inoculation/LPC vaccination. In addition, PCV2-derived inhibition of the CSFV-specific cell proliferative response of peripheral blood mononuclear cells (PBMCs was demonstrated in an ex vivo experiment. These findings indicate that PCV2 infection decreases the efficacy of the LPC vaccine. This PCV2-derived interference may not only allow the invasion of wild-type CSFV in pig farms but also increases the difficulty of CSF prevention and control in CSF endemic areas.

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

    International Nuclear Information System (INIS)

    Full text: Brucella abortus S-19 is the most commonly used attenuated live vaccine to prevent bovine brucellosis. The vaccine induces good levels of protection in cattle, preventing premature abortion. Although B. abortus S-19 is the most used vaccine in eradication campaigns worldwide, it has two major problems: (i) it produces abortion when administered to pregnant cattle and is fully virulent for humans and (ii), the presence of smooth lipopolysaccharide interferes with the discrimination between infected and vaccinated animals during immunescreening procedures. In our laboratory we have previously cloned, sequenced and disrupted the gene coding for the enzyme phosphoglucomutase (pgm), responsible for the interconversion of glucose-6P to glucose-1P. The mutant does not synthesize the sugar nucleotide UDP-glucose and/or ADP-glucose and thus is unable to form any polysaccharide containing glucose, galactose or any other sugars whose synthesis proceeds through a glucose-nucleotide intermediate. The mutant has a rough phenotype, is avirulent in mice but retains the ability to multiply inside HeLa cells, although it shows a delay of the exponential intracellular replication. These characteristics prompt us to evaluate the potential use of this strain as a new live rough vaccine. We generated an unmarked deletion mutant of pgm. Western blot analysis of purified lipopolysaccharide from Δpgm indicated that it is devoid of O-antigen, however Δpgm whole cell extracts contained detectable amounts of O-antigen with a MW of 45 kDa, indicating that mutant strain is able to synthesize O-antigen but incapable to assemble a complete LPS probably due to the presence of an altered core structure. When administered intraperitoneally in Balb/C mice, the number of viable Δpgm recovered from spleens were, at all tested times, significantly lower than those inoculated with the parental virulent strain S2308 and was completely cleared at 8 weeks p.i., thus indicating a severe

  8. A History of the Development of Brucella Vaccines

    Directory of Open Access Journals (Sweden)

    Eric Daniel Avila-Calderón

    2013-01-01

    Full Text Available Brucellosis is a worldwide zoonosis affecting animal and human health. In the last several decades, much research has been performed to develop safer Brucella vaccines to control the disease mainly in animals. Till now, no effective human vaccine is available. The aim of this paper is to review and discuss the importance of methodologies used to develop Brucella vaccines in pursuing this challenge.

  9. A developing country perspective on vaccine-associated paralytic poliomyelitis.

    OpenAIRE

    2004-01-01

    When the Expanded Programme on Immunization was established and oral poliovirus vaccine (OPV) was introduced for developing countries to use exclusively, national leaders of public health had no opportunity to make an informed choice between OPV and the inactivated poliovirus vaccine (IPV). Today, as progress is made towards the goal of global eradication of poliomyelitis attributable to wild polioviruses, all developing countries where OPV is used face the risk of vaccine-associated paralyti...

  10. Experience with registered mucosal vaccines.

    Science.gov (United States)

    Dietrich, Guido; Griot-Wenk, Monika; Metcalfe, Ian C; Lang, Alois B; Viret, Jean-François

    2003-01-30

    Most pathogens gain access to their host through mucosal surfaces. It is therefore desirable to develop vaccination strategies that lead to mucosal immune responses. Ideally, a vaccine should be administered mucosally in order to elicit mucosal protection. Several attenuated live viral and bacterial pathogens are registered as oral vaccines for human use, including the oral polio vaccine (Sabin) as well as attenuated strains of Salmonella typhi and Vibrio cholerae. These attenuated bacterial live vaccines-S. typhi Ty21a as well as V. cholerae CVD 103-HgR-are employed as vaccines against typhoid and cholera, respectively. In this manuscript, we review the immune responses that are induced by these vaccines, with a focus on mucosal immunity. PMID:12531339

  11. Status of research and development of vaccines for Streptococcus pyogenes.

    Science.gov (United States)

    Steer, Andrew C; Carapetis, Jonathan R; Dale, James B; Fraser, John D; Good, Michael F; Guilherme, Luiza; Moreland, Nicole J; Mulholland, E Kim; Schodel, Florian; Smeesters, Pierre R

    2016-06-01

    Streptococcus pyogenes is an important global pathogen, causing considerable morbidity and mortality, especially in low and middle income countries where rheumatic heart disease and invasive infections are common. There is a number of promising vaccine candidates, most notably those based on the M protein, the key virulence factor for the bacterium. Vaccines against Streptococcus pyogenes are considered as impeded vaccines because of a number of crucial barriers to development. Considerable effort is needed by key players to bring current vaccine candidates through phase III clinical trials and there is a clear need to develop a roadmap for future development of current and new candidates. PMID:27032515

  12. Design of nanomaterial based systems for novel vaccine development.

    Science.gov (United States)

    Yang, Liu; Li, Wen; Kirberger, Michael; Liao, Wenzhen; Ren, Jiaoyan

    2016-05-26

    With lower cell toxicity and higher specificity, novel vaccines have been greatly developed and applied to emerging infectious and chronic diseases. However, due to problems associated with low immunogenicity and complicated processing steps, the development of novel vaccines has been limited. With the rapid development of bio-technologies and material sciences, nanomaterials are playing essential roles in novel vaccine design. Incorporation of nanomaterials is expected to improve delivery efficiency, to increase immunogenicity, and to reduce the administration dosage. The purpose of this review is to discuss the employment of nanomaterials, including polymeric nanoparticles, liposomes, virus-like particles, peptide amphiphiles micelles, peptide nanofibers and microneedle arrays, in vaccine design. Compared to traditional methods, vaccines made from nanomaterials display many appealing benefits, including precise stimulation of immune responses, effective targeting to certain tissue or cells, and desirable biocompatibility. Current research suggests that nanomaterials may improve our approach to the design and delivery of novel vaccines. PMID:26891972

  13. Development and efficacy of novobiocin and rifampicin-resistant Aeromonas hydrophila as novel vaccines in channel catfish and Nile tilapia

    Science.gov (United States)

    Three attenuated Aeromonas hydrophila vaccines were developed from the virulent 2009 West Alabama isolates through selection for resistance to both novobiocin and rifampicin. When channel catfish (Ictalurus punctatus) were IP injected with 4×105 colony-forming units (CFU) of the mutants, no fish die...

  14. Development and efficacy of a noviobiocin-resistant Streptococcus iniae as a novel vaccine in Nile tilapia (Oreochromis niloticus)

    Science.gov (United States)

    A novel attenuated Streptococcus iniae vaccine was developed from a virulent strain of Streptococcus iniae (ISET0901) through selection for novobiocin resistance (therefore named ISNO). The safety of ISNO was then evaluated in Nile tilapia (Oreochromis niloticus) through intraperitoneal (IP) injecti...

  15. Reactogenicity and immunogenicity of a live-attenuated refrigerator-stable varicella vaccine (OKA strain) in healthy seronegative subjects age 10 months to 12 years.

    Science.gov (United States)

    Hadinegoro, S R H; Hindra, I S; Han, H H; Gatchalian, S; Bock, H L

    2009-09-01

    This study assessed the immunogenicity and reactogenicity of a live-attenuated varicella vaccine (Oka strain), Varilrix in Indonesian children age 10 months to 12 years. A total of 300 seronegative subjects were stratified into three age subgroups (10 months to 39 degrees C) was infrequent. No grade 3 unsolicited events and no serious adverse events were reported. The vaccine proved to be immunogenic in all age groups; all but one subject seroconverted for anti-varicella antibodies 43-days post-vaccination. This study demonstrated that the live-attenuated varicella vaccine (Oka strain) was well tolerated and immunogenic with no safety issues when administered as a single dose primary vaccination to healthy, seronegative Indonesian subjects age 10 months to 12 years. PMID:19842382

  16. Considerations for developing an immunization strategy with enterovirus 71 vaccine.

    Science.gov (United States)

    Li, Li; Yin, Hongzhang; An, Zhijie; Feng, Zijian

    2015-02-25

    Enterovirus 71 (EV71) is a common pathogen for hand, foot, and mouth disease (HFMD), which has significant morbidity and mortality, and for which children aged 6-59 months age are at highest risk. Due to lack of effective treatment options, control of EV71 epidemics has mainly focused on development of EV71 vaccines. Clinical trials have been completed on 3 EV71 vaccines, with trial results demonstrating good vaccine efficacy and safety. When EV71 vaccine is approved by China's national regulatory authority, an evidence-based strategy should be developed to optimize impact and safety. An immunization strategy for EV71 vaccine should consider several factors, including the target population age group, the number of doses for primary immunization, the need for a booster dose, concomitant administration of other vaccines, economic value, program capacity and logistics, and public acceptance. Once EV71 vaccines are in use, vaccine effectiveness and safety must be monitored in large populations, and the epidemiology of HFMD must be evaluated to assure a match between vaccination strategy and epidemiology. Evaluation in China is especially important because there are no other EV71 vaccines globally. PMID:25444807

  17. Candida vaccines development from point view of US patent application.

    Science.gov (United States)

    Wang, Shyh-Jen

    2011-11-01

    Candidiasis is the fourth most common bloodstream infection in hospitalized patients in the United States. Moreover, the mortality rate from Candida infections remains high, even after treatment with antifungal therapy. Vaccination would be a promising strategy for prevention of invasive fungal infections. In order to examine the main trends in anticandidal vaccine patenting activity, we conducted an analysis for anticandidal vaccine patents. We find 190 issued patent and 940 patent application documents containing the keywords Candida and vaccine within claims in the USA. Candida vaccines development, as evidenced by the numbers of issued patents, has decreased since the year 2002. Furthermore, the number of patent applications in Candida vaccines may indicate the strength of engaged resources were also in the status of stagnation during 2005-2007 and even a decline in 2008. Academic and nonprofit research institutions not only account for a large share of Candida vaccines patents but also apply for patents continually. Based on this analysis, the strength of Candida vaccines resources seems to remain stagnant in recent years due to patent prosecution or technical barrier in the filed of Candida vaccines. Therefore, we consider that Candida vaccines technology to still be under development and the researchers are still looking for scientific breakthrough in the filed. PMID:22048114

  18. [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. PMID:27029122

  19. Studies on tropical theileriosis in Turkey 5. Studies on Various Numbers of Attenuated Vaccine Cells Used in Cattle Against Tropical Theileriosis

    OpenAIRE

    SAYIN, Fahri; Nalbantoğlu, Serpil; Karaer, Zafer; Çakmak, Ayşe; DİNÇER, Şükran; Vatansever, Zati

    2004-01-01

    Since the total of 150,000 doses of attenuated cell culture vaccine doses produced anually in Turkey does not meet the requirements of the country, by reducing the number of vaccine cells in a single dose, an increased number of vaccine doses was obtained for cattle, and doses consisting of different numbers of vaccine cells were tested according to their protective efficiency against tropical theileriosis in cattle. Fifty Holstein calves aged 2.5-3 months were used: 42 of them were used in v...

  20. Development of an AIDS vaccine using Sendai virus vectors.

    Science.gov (United States)

    Ishii, Hiroshi; Matano, Tetsuro

    2015-11-01

    Development of an effective AIDS vaccine is crucial for the control of global human immunodeficiency virus type 1 (HIV-1) prevalence. We have developed a novel AIDS vaccine using a Sendai virus (SeV) vector and investigated its efficacy in a macaque AIDS model of simian immunodeficiency virus (SIV) infection. Its immunogenicity and protective efficacy have been shown, indicating that the SeV vector is a promising delivery tool for AIDS vaccines. Here, we describe the potential of SeV vector as a vaccine antigen delivery tool to induce effective immune responses against HIV-1 infection. PMID:26232346

  1. Novel strategies and approaches to develop the next generation of vaccines against porcine reproductive and respiratory syndrome virus (PRRSV).

    Science.gov (United States)

    Huang, Y W; Meng, X J

    2010-12-01

    Porcine reproductive and respiratory syndrome virus (PRRSV) is an economically important swine pathogen. Since its discovery in the early 1990 s, tremendous progresses have been made in understanding the molecular biology and pathogenesis of PRRSV. Although modified live-attenuated vaccines (MLVs) and inactivated vaccines against PRRSV have been available for more than a decade, the disease remains difficult to control. The efficacies of these vaccines especially against heterologous strains remain questionable: the MLVs were generally effective against homologous strains but variable in success against heterologous strains, and the outcomes of inactivated vaccines in the field are not very promising. With the development of PRRSV reverse genetics systems and the acquisition of new understanding on anti-PRRSV immunity, rational design of the next generation of PRRSV vaccines can now be explored. In this review, we discussed the recent advances in anti-PRRSV immunity and vaccinology, the recent progresses in PRRSV vaccine development particularly the reverse genetics system-based vaccine development, and provided a perspective on potential novel strategies and approaches that may be applicable to the development of the next generation of PRRSV vaccines. PMID:20655962

  2. Rotaviruses: from pathogenesis to vaccination

    OpenAIRE

    Greenberg, Harry B.; Estes, Mary K.

    2009-01-01

    Rotaviruses cause life-threatening gastroenteritis in children worldwide; the enormous disease burden has focused efforts to develop vaccines and led to the discovery of novel mechanisms of gastrointestinal virus pathogenesis and host responses to infection. Two live-attenuated vaccines for gastroenteritis (Rotateq and Rotarix) have been licensed in many countries. This review summarizes the latest data on these vaccines, their effectiveness and challenges to global vaccination. Recent insigh...

  3. Dengue: Challenges for Policy Makers and Vaccine Developers

    OpenAIRE

    Wilder-Smith, Annelies; Macary, Paul

    2014-01-01

    Because of the increasing incidence, geographic expansion and economic burden of dengue transmission, dengue poses major challenges to policy makers. A vaccine against dengue is urgently needed, but vaccine development has been hampered by the lack of an appropriate animal model, poor understanding of correlates of successful human immunity, the fear of immune enhancement, and viral interference in tetravalent combinations. The most suitable target epitopes for vaccines, as well as the role o...

  4. A morphine conjugate vaccine attenuates the behavioral effects of morphine in rats

    OpenAIRE

    Kosten, Therese A.; Shen, Xiaoyun Y.; O'Malley, Patrick W.; Kinsey, Berma M.; Lykissa, Ernest D.; Orson, Frank M.; Kosten, Thomas R.

    2013-01-01

    Vaccines for opioid dependence may provide a treatment that would reduce or slow the distribution of the drug to brain, thus reducing the drug's reinforcing effects. We tested whether a conjugate vaccine against morphine (keyhole limpet hemocyanin-6-succinylmorphine; KLH-6-SM) administered to rats would produce antibodies and show specificity for morphine or other heroin metabolites. The functional effects of the vaccine were tested with antinociceptive and conditioned place preference (CPP) ...

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

    International Nuclear Information System (INIS)

    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)

  6. Targeting TLR2 for Vaccine Development

    Directory of Open Access Journals (Sweden)

    Afonso P. Basto

    2014-01-01

    Full Text Available Novel and more effective immunization strategies against many animal diseases may profit from the current knowledge on the modulation of specific immunity through stimulation of innate immune receptors. Toll-like receptor (TLR2-targeting formulations, such as synthetic lipopeptides and antigens expressed in fusion with lipoproteins, have been shown to have built-in adjuvant properties and to be effective at inducing cellular and humoral immune mechanisms in different animal species. However, contradictory data has arisen concerning the profile of the immune response elicited. The benefits of targeting TLR2 for vaccine development are thus still debatable and more studies are needed to rationally explore its characteristics. Here, we resume the main features of TLR2 and TLR2-induced immune responses, focusing on what has been reported for veterinary animals.

  7. WHO policy development processes for a new vaccine: case study of malaria vaccines

    Directory of Open Access Journals (Sweden)

    Cheyne James

    2010-06-01

    Full Text Available Abstract Background Recommendations from the World Health Organization (WHO are crucial to inform developing country decisions to use, or not, a new intervention. This article analysed the WHO policy development process to predict its course for a malaria vaccine. Methods The decision-making processes for one malaria intervention and four vaccines were classified through (1 consultations with staff and expert advisors to WHO's Global Malaria Programme (GMP and Immunization, Vaccines and Biologicals Department (IVB; (2 analysis of the procedures and recommendations of the major policy-making bodies of these groups; (3 interviews with staff of partnerships working toward new vaccine availability; and (4 review and analyses of evidence informing key policy decisions. Case description WHO policy formulation related to use of intermittent preventive treatment in infancy (IPTi and the following vaccine interventions: Haemophilus influenzae type b conjugate vaccine (Hib, pneumococcal conjugate vaccine (PCV, rotavirus vaccine (RV, and human papillomavirus vaccine (HPV, five interventions which had relatively recently been through systematic WHO policy development processes as currently constituted, was analysed. Required information was categorized in three areas defined by a recent WHO publication on development of guidelines: safety and efficacy in relevant populations, implications for costs and population health, and localization of data to specific epidemiological situations. Discussion and evaluation Data needs for a malaria vaccine include safety; the demonstration of efficacy in a range of epidemiological settings in the context of other malaria prevention interventions; and information on potential rebound in which disease increases subsequent to the intervention. In addition, a malaria vaccine would require attention to additional factors, such as costs and cost-effectiveness, supply and demand, impact of use on other interventions, and

  8. United States of America Department of Health and Human Services support for advancing influenza vaccine manufacturing in the developing world.

    Science.gov (United States)

    Perdue, Michael L; Bright, Rick A

    2011-07-01

    five years of age. In addition to achievements described in this issue of Vaccine, the programme has been successful from the US perspective because the working relationships established between the US Department of Health and Human Services' (HHS) Assistant Secretary for Preparedness and Response Biomedical Advanced Research and Development Authority (BARDA) and its partners have assisted in advancing influenza vaccine development at many different levels. A few examples of BARDA's support include: establishment of egg-based influenza vaccine production from "scratch", enhancement of live attenuated influenza vaccine (LAIV) production techniques and infrastructure, completion of fill/finish operations for imported bulk vaccine, and training in advanced bio-manufacturing techniques. These HHS-supported programmes have been well-received internationally, and we and our partners hope the successes will stimulate even more interest within the international community in maximizing global production levels for influenza vaccines. PMID:21684430

  9. A morphine conjugate vaccine attenuates the behavioral effects of morphine in rats.

    Science.gov (United States)

    Kosten, Therese A; Shen, Xiaoyun Y; O'Malley, Patrick W; Kinsey, Berma M; Lykissa, Ernest D; Orson, Frank M; Kosten, Thomas R

    2013-08-01

    Vaccines for opioid dependence may provide a treatment that would reduce or slow the distribution of the drug to brain, thus reducing the drug's reinforcing effects. We tested whether a conjugate vaccine against morphine (keyhole limpet hemocyanin-6-succinylmorphine; KLH-6-SM) administered to rats would produce antibodies and show specificity for morphine or other heroin metabolites. The functional effects of the vaccine were tested with antinociceptive and conditioned place preference (CPP) tests. Rats were either vaccinated with KLH-6-SM and received two boosts 3 and 16 weeks later or served as controls and received KLH alone. Anti-morphine antibodies were produced in vaccinated rats; levels increased and were sustained at moderate levels through 24 weeks. Antibody binding was inhibited by free morphine and other heroin metabolites as demonstrated by competitive inhibition ELISA. Vaccinated rats showed reduced morphine CPP, tested during weeks 4 to 6, and decreased antinociceptive responses to morphine, tested at week 7. Brain morphine levels, assessed using gas-chromatography coupled to mass spectrometry (GC-MS) on samples obtained at 26 weeks, were significantly lower in vaccinated rats. This suggests that morphine entry into the brain was reduced or slowed. These results provide support for KLH-6-SM as a candidate vaccine for opioid dependence. PMID:23739535

  10. Vaccinations

    Science.gov (United States)

    ... vaccinated? For many years, a set of annual vaccinations was considered normal and necessary for dogs and ... to protect for a full year. Consequently, one vaccination schedule will not work well for all pets. ...

  11. Tuberculosis vaccine development: Shifting focus amid increasing development challenges.

    Science.gov (United States)

    Graves, A J; Hokey, D A

    2015-01-01

    A new tuberculosis vaccine is needed to replace or enhance BCG, which induces variable protection against Mycobacterium tuberculosis pulmonary infections in adults. Development of new TB vaccine candidates is severely hampered by the lack of a correlate of immunity, unproven animal models, and limited funding opportunities. One candidate, MVA85A, recently failed to meet its efficacy endpoint goals despite promising early-phase trial data. As a result, some in the field believe we should now shift our focus away from product development and toward a research-oriented approach. Here, we outline our suggestions for this research-oriented strategy including diversification of the candidate pipeline, expanding measurements of immunity, improving pre-clinical animal models, and investing in combination pre-clinical/experimental medicine studies. As with any evolution, this change in strategy comes at a cost but may also represent an opportunity for advancing the field. PMID:26125249

  12. Evaluation of the protection elicited by direct and indirect exposure to live attenuated infectious laryngotracheitis virus vaccines against a recent challenge strain from the United States.

    Science.gov (United States)

    Rodríguez-Avila, Andrés; Oldoni, Ivomar; Riblet, Sylva; Garcia, Maricarmen

    2008-06-01

    In a recent study (Oldoni & García, 2007), some field strains of infectious laryngotracheitis viruses (ILTV) were characterized as genotypically different (group VI) from ILT vaccine strains. The objective of this study was to evaluate the protection elicited by one chicken embryo origin (CEO) and one tissue culture origin (TCO) vaccine against a field isolate from group VI after direct and indirect exposure to ILTV live attenuated vaccines. In phase 1 of the experiment, non-vaccinated chickens were placed into contact with the eye drop vaccinates for a period of four weeks after vaccination. Transmission of the vaccine virus to these in-contact birds was demonstrated by real time PCR and antibody production, although the in-contact birds did not become protected against disease when subsequently challenged in phase 2 of the experiment. This emphasized the importance of uniform vaccination to obtain adequate protection, both to avoid the occurrence of susceptible chickens, and to minimize the potential for reversion to virulence of live-attenuated vaccines. In phase 2, protection against challenge with a group VI field virus was assessed four weeks after vaccination by scoring clinical signs and mortality, and quantifying weight gain. Sentinel birds were added to the groups one day after challenge to assess shedding of challenge virus, using real time PCR and virus isolation, during the period 2 to 12 days post challenge. The results showed that the CEO and TCO eye drop-vaccinated chickens were protected against challenge with the group VI virus, even though it was genetically different from the vaccine strains, and that challenge virus was not transmitted from these protected birds to the sentinels. PMID:18568655

  13. Novel approaches to foot-and-mouth disease vaccine development

    Science.gov (United States)

    The need for better Foot-and-mouth disease (FMD) vaccines is not new, a report from the Research Commission on FMD, authored by F. Loeffler and P. Frosch in 1897, highlighted the need for developing a vaccine against FMD and qualified this as a devastating disease causing “severe economic damage to ...

  14. Developments of Subunit and VLP Vaccines Against Influenza A Virus

    Institute of Scientific and Technical Information of China (English)

    Ma-ping Deng; Zhi-hong Hu; Hua-lin Wang; Fei Deng

    2012-01-01

    Influenza virus is a continuous and severe global threat to mankind.The continuously re-emerging disease gives rise to thousands of deaths and enormous economic losses each year,which emphasizes the urgency and necessity to develop high-quality influenza vaccines in a safer,more efficient and economic way.The influenza subunit and VLP vaccines,taking the advantage of recombinant DNA technologies and expression system platforms,can be produced in such an ideal way.This review summarized the recent advancements in the research and development of influenza subunit and VLP vaccines based on the recombinant expression of hemagglutinin antigen (HA),neuraminidase antigen (NA),Matrix 2 protein (M2) and nucleocapsid protein (NP).It would help to get insight into the current stage of influenza vaccines,and suggest the future design and development of novel influenza vaccines.

  15. Current state in the development of candidate therapeutic HPV vaccines.

    Science.gov (United States)

    Yang, Andrew; Jeang, Jessica; Cheng, Kevin; Cheng, Ting; Yang, Benjamin; Wu, T-C; Hung, Chien-Fu

    2016-08-01

    The identification of human papillomavirus (HPV) as an etiological factor for HPV-associated malignancies creates the opportunity to control these cancers through vaccination. Currently, available preventive HPV vaccines have not yet demonstrated strong evidences for therapeutic effects against established HPV infections and lesions. Furthermore, HPV infections remain extremely common. Thus, there is urgent need for therapeutic vaccines to treat existing HPV infections and HPV-associated diseases. Therapeutic vaccines differ from preventive vaccines in that they are aimed at generating cell-mediated immunity rather than neutralizing antibodies. The HPV-encoded early proteins, especially oncoproteins E6 and E7, form ideal targets for therapeutic HPV vaccines since they are consistently expressed in HPV-associated malignancies and precancerous lesions, playing crucial roles in the generation and maintenance of HPV-associated disease. Our review will cover various therapeutic vaccines in development for the treatment of HPV-associated lesions and cancers. Furthermore, we review strategies to enhance vaccine efficacy and the latest clinical trials on therapeutic HPV vaccines. PMID:26901118

  16. Vaccine development for Tuberculosis: Past, Present and Future Challenges

    Directory of Open Access Journals (Sweden)

    Dileep Tiwari

    2011-06-01

    Full Text Available About one third of the world's population is infected with Mycobacterium tuberculosis (M. tb, and new infections occur at a rate of about one per second. Additionally, more people in the developed world contact tuberculosis (TB because their immune systems are more likely to be compromised due to higher exposure to immunosuppressive drugs, substance abuse, or AIDS. The distribution of tuberculosis is not uniform across the globe, still the treatment is difficult and requires long courses of multiple antibiotics. However, antibiotic resistance is a growing problem in multidrugresistant (MDR tuberculosis. But mostly the prevention relies on screening programs and vaccination, usually with Bacillus Calmette- Guérin (BCG vaccine. BCG is the most commonly used vaccine worldwide, but not as a powerful vaccine. BCG also provides some protection against severe forms of pediatric TB, but has been shown to be unreliable against adult pulmonary TB which accounts for most of the disease burden worldwide. Currently, there is an urgent need for novel, more effective vaccine that can prevent all forms of TB including drug resistant strains for all age groups and among people with HIV. The first recombinant tuberculosis vaccine rBCG30, entered clinical trials in year 2004, but, still no effective vaccine is available in a market. Study showed that DNA TB vaccine given with conventional chemotherapy can accelerate the disappearance of bacteria as well as protect against re-infection in mice and it is quite effective against TB. A very promising TB vaccine, MVA85A, is currently in phase II trials and is based on a genetically modified vaccinia virus. Many other strategies are also being used to develop novel vaccines, including both subunit vaccines such as Hybrid-1, HyVac4 or M72, and recombinant adenoviruses such as Ad35. Some of these vaccines can be effectively administered without needles making them preferable for areas where HIV is very common and few of

  17. The influence of the multi-basic cleavage site of the H5 hemagglutinin on the attenuation, immunogenicity and efficacy of a live attenuated influenza A h5N1 cold-adapted vaccine virus

    Science.gov (United States)

    A recombinant live attenuated influenza virus (LAIV) deltaH5N1 vaccine with a modified hemagglutinin (HA) and intact neuraminidase genes from A/Vietnam/1203/04 (H5N1) and the six remaining genome segments from A/Ann Arbor/6/60 (H2N2) cold-adapted (AA ca) virus was attenuated in chickens, mice and fe...

  18. Reversion to neurovirulence of the live-attenuated Sabin type 3 oral poliovirus vaccine.

    OpenAIRE

    Cann, A J; Stanway, G; Hughes, P J; Minor, P D; Evans, D.M.; Schild, G. C.; Almond, J W

    1984-01-01

    The complete nucleotide sequence has been determined of a strain of poliovirus type 3, P3/119, isolated from the central nervous system of a victim of fatal vaccine-associated poliomyelitis. Comparison of this sequence with those obtained previously for the Sabin type 3 vaccine, P3/Leon 12a1b and its neurovirulent progenitor, P3/Leon/37, reveals that these three strains are on a direct geneaological lineage and therefore that P3/119 is a bona fide revertant of the vaccine. P3/119 differs in s...

  19. Advances in the development of next-generation anthrax vaccines.

    Science.gov (United States)

    Friedlander, Arthur M; Little, Stephen F

    2009-11-01

    Anthrax, a disease of herbivores, only rarely infects humans. However, the threat of using Bacillus anthracis, the causative agent, to intentionally produce disease has been the impetus for development of next-generation vaccines. Two licensed vaccines have been available for human use for several decades. These are composed of acellular culture supernatants containing the protective antigen (PA) component of the anthrax toxins. In this review we summarize the various approaches used to develop improved vaccines. These efforts have included the use of PA with newer adjuvants and delivery systems, including bacterial and viral vectors and DNA vaccines. Attempts to broaden the protection afforded by PA-based vaccines have focused on adding other B. anthracis components, including spore and capsule antigens. PMID:19837282

  20. Development of Fasciola Vaccine in an Animal Model.

    Science.gov (United States)

    Meemon, Krai; Sobhon, Prasert

    2016-01-01

    Fasciola hepatica and F. gigantica are the parasites that cause the zoonotic parasitic disease called fasciolosis. Although several anthelmintic drugs have been used to treat these parasitic infections, recombinant protein vaccines have been developed to overcome the anthelmintic resistance that has recently been reported in many regions of the world. These vaccines have been shown to induce high levels of immune responses and high percentages of protection in experimental and large animals. Efficacies of these vaccines suggest they could be an alternative and sustainable strategy to prevent fasciolosis in animals as well as humans in the future. The purpose of this chapter is to provide a protocol to develop a recombinant protein-based vaccine against Fasciola infection in mice. Moreover, this method can also be used as a guideline when the vaccination is performed in larger animals. PMID:27076294

  1. Divergent Immunomodulating Effects of Probiotics on T Cell Responses to Oral Attenuated Human Rotavirus Vaccine and Virulent Human Rotavirus Infection in a Neonatal Gnotobiotic Piglet Disease Model

    OpenAIRE

    Chattha, Kuldeep S; Vlasova, Anastasia N.; Kandasamy, Sukumar; Rajashekara, Gireesh; Saif, Linda J.

    2013-01-01

    Rotaviruses (RVs) are a leading cause of childhood diarrhea. Current oral vaccines are not effective in impoverished countries where the vaccine is needed most. Therefore, alternative affordable strategies are urgently needed. Probiotics can alleviate diarrhea in children and enhance specific systemic and mucosal Ab responses, but the T cell responses are undefined. In this study, we elucidated the T cell and cytokine responses to attenuated human RV (AttHRV) and virulent human RV (HRV) in gn...

  2. DEVELOPEMENT OF A LIGHT ATTENUATOR BASED ON GLASSY REFLECTIONS

    Directory of Open Access Journals (Sweden)

    K. Ferria

    2015-07-01

    Full Text Available The light intensity control of a luminous source is a very important operation in many optical applications. Several types of light attenuator exploiting different optical phenomena like diffraction, absorption, and reflection exist and they differ principally in the maximum attenuation rate, the control range, the sensitivity and the spectral band. In the presented work, we have developed and designed a light attenuator based on the progressive decrease of the transmitted light intensity, when it undergoes multiple vitreous reflections across eight plates glasses arranged in a roof shape. Several tests were carried out using a laser light as a source. We have shown that the attenuation rate can be controlled by the choice of the incidence angle on the glasses slides, in addition we have confirmed, for the case of perpendicular polarization of the laser light, that the attenuation obeys to a linear function. The obtained results are very close to those predicted theoretically.

  3. Refined live attenuated Salmonella enterica serovar Typhimurium and Enteritidis vaccines mediate homologous and heterologous serogroup protection in mice.

    Science.gov (United States)

    Tennant, Sharon M; Schmidlein, Patrick; Simon, Raphael; Pasetti, Marcela F; Galen, James E; Levine, Myron M

    2015-12-01

    Invasive nontyphoidal Salmonella (NTS) infections constitute a major health problem among infants and toddlers in sub-Saharan Africa; these infections also occur in infants and the elderly in developed countries. We genetically engineered a Salmonella enterica serovar Typhimurium strain of multilocus sequence type 313, the predominant genotype circulating in sub-Saharan Africa. We evaluated the capacities of S. Typhimurium and Salmonella enterica serovar Enteritidis ΔguaBA ΔclpX live oral vaccines to protect mice against a highly lethal challenge dose of the homologous serovar and determined protection against other group B and D serovars circulating in sub-Saharan Africa. The vaccines S. Typhimurium CVD 1931 and S. Enteritidis CVD 1944 were immunogenic and protected BALB/c mice against 10,000 50% lethal doses (LD50) of S. Typhimurium or S. Enteritidis, respectively. S. Typhimurium CVD 1931 protected mice against the group B serovar Salmonella enterica serovar Stanleyville (91% vaccine efficacy), and S. Enteritidis CVD 1944 protected mice against the group D serovar Salmonella enterica serovar Dublin (85% vaccine efficacy). High rates of survival were observed when mice were infected 12 weeks postimmunization, indicating that the vaccines elicited long-lived protective immunity. Whereas CVD 1931 did not protect against S. Enteritidis R11, CVD 1944 did mediate protection against S. Typhimurium D65 (81% efficacy). These findings suggest that a bivalent (S. Typhimurium and S. Enteritidis) vaccine would provide broad protection against the majority of invasive NTS infections in sub-Saharan Africa. PMID:26351285

  4. Development of DNA vaccines for fish

    DEFF Research Database (Denmark)

    Heppell, Joël; Lorenzen, Niels; Armstrong, Neil K.;

    1998-01-01

    Disease control is one of the major concerns in the aquaculture industry. However, there are no vaccines available for the prevention of many piscine infectious diseases, especially those of viral and parasitic origin. DNA-based vaccination could circumvent several problems associated with...... permanent tissue damage. To further investigate the ability of DNA-based vaccines to induce protective immunity in fish, viral haemorrhagic septicaemia virus G and N genes were cloned individually into an expression plasmid. Both G and N proteins produced in transfected fish cells appeared identical to...... protein, killing the transfected host cells and ablating further expression of G protein and luciferase. Finally, young rainbow trout injected with the G construct, alone or together with the N construct, were strongly protected against challenge with live virus. These results suggest that DNA vaccines...

  5. Presenting a foreign antigen on live attenuated Edwardsiella tarda using twin-arginine translocation signal peptide as a multivalent vaccine.

    Science.gov (United States)

    Wang, Yamin; Yang, Weizheng; Wang, Qiyao; Qu, Jiangbo; Zhang, Yuanxing

    2013-12-01

    The twin-arginine translocation (Tat) system is a major pathway for transmembrane translocation of fully folded proteins. In this study, a multivalent vaccine to present foreign antigens on live attenuated vaccine Edwardsiella tarda WED using screened Tat signal peptide was constructed. Because the Tat system increases the yields of folded antigens in periplasmic space or extracellular milieu, it is expected to contribute to the production of conformational epitope-derived specific antibodies. E. tarda Tat signal peptides fused with the green fluorescent protein (GFP) was constructed under the control of an in vivo inducible dps promoter. The resulting plasmids were electroporated into WED and the subcellular localizations of GFP were analyzed with Western blotting. Eight signal peptides with optimized GFP translocation efficiency were further fused to a protective antigen glyceraldehyde-3-phosphate dehydrogenase (GapA) from a fish pathogen Aeromonas hydrophila. Signal peptides of DmsA, NapA, and SufI displayed high efficiency for GapA translocation. The relative percent survival (RPS) of turbot was measured with a co-infection of E. tarda and A. hydrophila, and the strain with DmsA signal peptide showed the maximal protection. This study demonstrated a new platform to construct multivalent vaccines using optimized Tat signal peptide in E. tarda. PMID:23994481

  6. Single dose attenuated Vesiculovax vaccines protect primates against Ebola Makona virus

    OpenAIRE

    Mire, Chad E.; Matassov, Demetrius; Joan B Geisbert; Latham, Theresa E.; Agans, Krystle N.; Xu, Rong; Ota-Setlik, Ayuko; Egan, Michael A.; Fenton, Karla A.; Clarke, David K.; Eldridge, John H.; Geisbert, Thomas W.

    2015-01-01

    The family Filoviridae contains three genera, Ebolavirus (EBOV), Marburg virus, and Cuevavirus 1 . Some members of the EBOV genus, including Zaire ebolavirus (ZEBOV), can cause lethal hemorrhagic fever in humans. During 2014 an unprecedented ZEBOV outbreak occurred in West Africa and is still ongoing, resulting in nearly 10,000 deaths, and causing global concern of uncontrolled disease. To meet this challenge a rapid acting vaccine is needed. Many vaccine approaches have shown promise in bein...

  7. Live attenuated measles vaccine expressing HIV-1 Gag virus like particles covered with gp160ΔV1V2 is strongly immunogenic

    International Nuclear Information System (INIS)

    Although a live attenuated HIV vaccine is not currently considered for safety reasons, a strategy inducing both T cells and neutralizing antibodies to native assembled HIV-1 particles expressed by a replicating virus might mimic the advantageous characteristics of live attenuated vaccine. To this aim, we generated a live attenuated recombinant measles vaccine expressing HIV-1 Gag virus-like particles (VLPs) covered with gp160ΔV1V2 Env protein. The measles-HIV virus replicated efficiently in cell culture and induced the intense budding of HIV particles covered with Env. In mice sensitive to MV infection, this recombinant vaccine stimulated high levels of cellular and humoral immunity to both MV and HIV with neutralizing activity. The measles-HIV virus infected human professional antigen-presenting cells, such as dendritic cells and B cells, and induced efficient presentation of HIV-1 epitopes and subsequent activation of human HIV-1 Gag-specific T cell clones. This candidate vaccine will be next tested in non-human primates. As a pediatric vaccine, it might protect children and adolescents simultaneously from measles and HIV.

  8. Sequencing and characterization of Varicella-Zoster virus vaccine strain SuduVax

    OpenAIRE

    Kim Jong; Jung Gyoo; Kim Yu; Ji Ga; Kim Hyung; Wang Wen; Park Ho; Park Song; Kim Geun; Kwon Shi; Lee Keon; Ahn Jin; Yoon Yeup; Lee Chan

    2011-01-01

    Abstract Background Varicella-zoster virus (VZV) causes chickenpox in children and shingles in older people. Currently, live attenuated vaccines based on the Oka strain are available worldwide. In Korea, an attenuated VZV vaccine has been developed from a Korean isolate and has been commercially available since 1994. Despite this long history of use, the mechanism for the attenuation of the vaccine strain is still elusive. We attempted to understand the molecular basis of attenuation mechanis...

  9. Immunization of aged pigs with attenuated pseudorabies virus vaccine combined with CpG oligodeoxynucleotide restores defective Th1 immune responses.

    Directory of Open Access Journals (Sweden)

    Feiping Ming

    Full Text Available BACKGROUND AND AIMS: Attempts to immunize aged subjects often result in the failure to elicit a protective immune response. Murine model studies have shown that oligonucleotides containing CpG motifs (CpG ODN can stimulate immune system in aged mice as effectively as in young mice. Since many physiological and pathophysiological data of pigs can be transferred to humans, research in pigs is important to confirm murine data. Here we investigated whether immunization of aged pig model with attenuated pseudorabies virus vaccine (PRV vaccine formulated with CpG ODN could promote a successful development of immune responses that were comparable to those induced in young pigs in a similar manner. METHODOLOGY: Young and aged pigs were immunized IM with PRV vaccine alone, or in combination with CpG ODN respectively. At days 3, 7, 14 post immunization sera were assayed by ELISA for IgG titres, at day 7 for IgG1 and IgG2 subtypes titres. All blood samples collected in evacuated test tubes with K-EDTA at day 7 were analyzed for flow cytometer assay. Blood samples at day 7 collected in evacuated test tubes with heparin were analysed for antigen-specific cytokines production and peripheral blood mononuclear cells (PBMCs proliferative responses. RESULTS: CpG ODN could enhance Th1 responses (PRV-specific IgG2/IgG1 ratio, proliferative responses, Th1 cytokines production when used as an adjuvant for the vaccination of aged pigs, which were correlated with enhanced CD4+ T cells percentage, decreased CD4+CD8+CD45RO+ T cells percentage and improved PRV-specific CD4+ T cells activation. CONCLUSIONS: Our results demonstrate a utility for CpG ODN, as a safe vaccine adjuvant for promoting effective systemic immune responses in aged pig model. This agent could have important clinical uses in overcoming some of age-associated depressions in immune function that occur in response to vaccination.

  10. The possible use of 60Co irradiation attenuated vaccine for the control of human Leishmaniasis in Ethiopia. Part of a coordinated programme on the use of nuclear techniques in the preparation of vaccines against parasitic diseases

    International Nuclear Information System (INIS)

    Radiation effects and the evaluation of radiation-attenuated organisms as vaccines was studied with Leishmania enriettii infections in guinea pigs. The use of heat-killed or live but radiation-attenuated promastigotes with or without the concurrent use of BCG as adjuvant failed to elicit protection to challenge with normal virulent organisms. The effects of varying several factors such as irradiation dose, internal from vaccination to challenge, and the use of irradiated macrophages infected with leishmanial organisms failed to elicit protective immunity

  11. Cross-stage immunity for malaria vaccine development.

    Science.gov (United States)

    Nahrendorf, Wiebke; Scholzen, Anja; Sauerwein, Robert W; Langhorne, Jean

    2015-12-22

    A vaccine against malaria is urgently needed for control and eventual eradication. Different approaches are pursued to induce either sterile immunity directed against pre-erythrocytic parasites or to mimic naturally acquired immunity by controlling blood-stage parasite densities and disease severity. Pre-erythrocytic and blood-stage malaria vaccines are often seen as opposing tactics, but it is likely that they have to be combined into a multi-stage malaria vaccine to be optimally safe and effective. Since many antigenic targets are shared between liver- and blood-stage parasites, malaria vaccines have the potential to elicit cross-stage protection with immune mechanisms against both stages complementing and enhancing each other. Here we discuss evidence from pre-erythrocytic and blood-stage subunit and whole parasite vaccination approaches that show that protection against malaria is not necessarily stage-specific. Parasites arresting at late liver-stages especially, can induce powerful blood-stage immunity, and similarly exposure to blood-stage parasites can afford pre-erythrocytic immunity. The incorporation of a blood-stage component into a multi-stage malaria vaccine would hence not only combat breakthrough infections in the blood should the pre-erythrocytic component fail to induce sterile protection, but would also actively enhance the pre-erythrocytic potency of this vaccine. We therefore advocate that future studies should concentrate on the identification of cross-stage protective malaria antigens, which can empower multi-stage malaria vaccine development. PMID:26469724

  12. Challenges in the research and development of new human vaccines

    Directory of Open Access Journals (Sweden)

    T. Barbosa

    2013-02-01

    Full Text Available The field of vaccinology was born from the observations by the fathers of vaccination, Edward Jenner and Louis Pasteur, that a permanent, positive change in the way our bodies respond to life-threatening infectious diseases can be obtained by specific challenge with the inactivated infectious agent performed in a controlled manner, avoiding the development of clinical disease upon exposure to the virulent pathogen. Many of the vaccines still in use today were developed on an empirical basis, essentially following the paradigm established by Pasteur, “isolate, inactivate, and inject” the disease-causing microorganism, and are capable of eliciting uniform, long-term immune memory responses that constitute the key to their proven efficacy. However, vaccines for pathogens considered as priority targets of public health concern are still lacking. The literature tends to focus more often on vaccine research problems associated with specific pathogens, but it is increasingly clear that there are common bottlenecks in vaccine research, which need to be solved in order to advance the development of the field as a whole. As part of a group of articles, the objective of the present report is to pinpoint these bottlenecks, exploring the literature for common problems and solutions in vaccine research applied to different situations. Our goal is to stimulate brainstorming among specialists of different fields related to vaccine research and development. Here, we briefly summarize the topics we intend to deal with in this discussion.

  13. Development of inactivated-local isolate vaccine for infectious bronchitis

    Directory of Open Access Journals (Sweden)

    Darminto

    1999-06-01

    Full Text Available Infectious bronchitis (IB is an acute highly contagious viral respiratory disease of poultry caused by coronavirus. The disease causes high mortality in young chicks, reduce body weight gain in broilers and remarkable drop in egg production. IB can only be controlled by vaccination, but due to the antigenic variation among serotypes of IB viruses, the effective IB vaccine should be prepared from local isolates. The aim of this research is to develop inactivated IB vaccine derived from local IB isolates. Local isolates of IB viruses designated as I-37, I-269 and PTS-III were propagated respectively in specific pathogen free (SPF chicken eggs, the viruses then were inactivated by formaline at final concentration of 1:1,000. Subsequently, the inactivated viruses were mixed and emulsified in oil emulsion adjuvant with sorbitant mono-oleic as an emulsifier. The vaccine then was tested for its safety, potency and efficacy in broiler chickens. Birds inoculated twice with a two-week interval by inactivated vaccine did not show any adverse reaction, either systemic or local reaction. The inoculated birds developed antibody responses with high titre, while antibody of the control birds remain negative. In addition, efficacy test which was conducted in broilers demonstrated that birds vaccinated by live-commercial vaccine and boosted three weeks later by Balitvet inactivated vaccine showed high level of antibody production which provided high level of protection against challenged virus (76% against I-37, 92% against I-269 and 68% against PTS-III challenge viruses. From this study, it can be concluded that inactivated local IB vaccine is considered to be safe, potent and efficacious. The vaccine stimulates high titre of antibody responses, which provide high level of protection against challenged viruses.

  14. Development and evaluation of the TD97 measles virus vaccine

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, K.; Morita, M.; Katoh, M.; Kidokoro, M.; Saika, S.; Yoshizawa, S.; Hashizume, S.; Horiuchi, K.; Okabe, N.; Shinozaki, T. (Chiba Serum Institute (Japan))

    1990-11-01

    The TD97 strain vaccine virus was prepared from the Tanabe strain measles virus by low-temperature passages in primary cell cultures and ultraviolet (UV) mutagenesis. The TD97 strain exhibited the following characteristics: highly temperature sensitive, neither multiplying nor forming any plaques at 40 degrees C in Vero cells; genetically stable, maintaining high temperature sensitivity after ten successive passages in CE cells at 30 degrees C or 35 degrees C; and M proteins of this virus about 1 KD slower in mobility in SDS-PAGE than that of the Tanabe strain. The TD97 strain was further confirmed to be attenuated by an inoculation test into primate brain. In field trials, 752 healthy children were inoculated with a live virus vaccine prepared with this strain, and the following results were obtained: the seroconversion rate was 97% (517/533), and the average HI antibody titer was 2(5.2). An antibody-increasing effect was also observed in children who were initially seropositive. In children who seroconverted, the rates of fever were 15.7% (55/351) for 37.5 degrees C or higher and 4.0% (14/351) for 39 degrees C or higher. The rash rate was 7.7% (27/351), and the incidence of local reaction was 5.4% (19/351). The TD97 strain is thus considered to be suitable in use for an attenuated measles vaccine.

  15. Cross-stage immunity for malaria vaccine development

    OpenAIRE

    Nahrendorf, Wiebke; Scholzen, Anja; Sauerwein, Robert W; Langhorne, Jean

    2015-01-01

    Highlights • Antigens are shared between liver and blood-stage malaria parasites. • Cross-stage antigens can mediate protection which is life cycle stage transcending. • Multi-stage malaria vaccine development should identify cross-stage antigens.

  16. Foot-and-mouth disease vaccines: progress and problems.

    Science.gov (United States)

    Cao, Yimei; Lu, Zengjun; Liu, Zaixin

    2016-06-01

    Foot-and-mouth disease (FMD) has been a major threat to livestock across the world. The predominant method of controlling this disease in endemic regions is through regular vaccination with inactivated vaccine. However, there are many limitations. For instance, cultivation of virulent FMD virus (FMDV) in the manufacturing units poses a risk of escape from production sites. Vaccines may sometimes contain traces of FMD viral non-structural proteins (NSPs), therefore, interfering with the NSP-based serological differentiation infected from vaccinated animals (DIVA). Moreover, vaccines are unable to eliminate virus from carrier animals. To address the shortcomings of inactivated vaccines, many efforts are currently devoted to develop novel vaccines including attenuated and/or marker inactivated vaccines, recombinant protein vaccines, synthetic peptide vaccines, and empty capsid vaccines. Here, we review the research progress of novel vaccines, problems that remain to be solved, and also raise some suggestions that would help in the development of FMD vaccines. PMID:26760264

  17. Host protective immunity and vaccine development studies in lymphatic filariasis

    OpenAIRE

    Reddy, M. V. R.; Alli, R.; Harinath, B. C.

    2000-01-01

    Lymphatic filariasis caused mainly by infection fromWuchereria bancrofti andBrugia malayi remains as the major cause of clinical morbidity in tropical and subtropical countries. Development of vaccine against filarial infection can act as additional measure to the existing therapeutic and vector control methods in the control of this disease. The main hurdles in the development of anti-filarial vaccine are the strict primate specificity ofWuchereria bancrofti, the paucity of parasite material...

  18. Development of a vaccine for bacterial kidney disease in salmon

    International Nuclear Information System (INIS)

    This document is the executive summary and background review for the final report of ''Development of a Vaccine for Bacterial Kidney Disease in Salmon''. A description of the disease is provided, with microbiological characterization of the infective agent. A brief discussion of attempts to eradicate the disease is included. Recent progress in vaccine development and attempts to control the disease through pharmacological means are described, along with potential ways to break the cycle of infection. 80 refs

  19. Current status of vaccine development for tularemia preparedness

    OpenAIRE

    Hong, Kee-Jong; Park, Pil-Gu; Seo, Sang-Hwan; Rhie, Gi-eun; Hwang, Kyuh-Jam

    2013-01-01

    Tularemia is a high-risk infectious disease caused by Gram-negative bacterium Francisella tularensis. Due to its high fatality at very low colony-forming units (less than 10), F. tularensis is considered as a powerful potential bioterrorism agent. Vaccine could be the most efficient way to prevent the citizen from infection of F. tularensis when the bioterrorism happens, but officially approved vaccine with both efficacy and safety is not developed yet. Research for the development of tularem...

  20. Promoting HIV vaccine research and development in China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Anational strategy for the HIV vaccine research and development (R&D) should be formulated as soon as possible so as to ensure a sound progress in this field, urges a report by the Academic Divisions of the Chinese Academy of Sciences (CASAD), the top national advisory body in science and technology. Entitled "A Proposal on China's Strategy of the HIV Vaccine Research and Development,"the report has recently been submitted to the State Council, the country's cabinet.

  1. Extended safety and efficacy studies of the attenuated Brucella vaccine candidates 16 M(Delta)vjbR and S19(Delta)vjbR in the immunocompromised IRF-1-/- mouse model.

    Science.gov (United States)

    Arenas-Gamboa, A M; Rice-Ficht, A C; Fan, Y; Kahl-McDonagh, M M; Ficht, T A

    2012-02-01

    The global distribution of brucellosis and high incidence in certain areas of the world warrant the development of a safer and efficacious vaccine. For the past 10 years, we have focused our attention on the development of a safer, but still highly protective, live attenuated vaccine for human and animal use. We have demonstrated the safety and protective efficacy of the vaccine candidates 16 MΔvjbR and S19ΔvjbR against homologous and heterologous challenge in multiple immunocompetent animal models, including mice and deer. In the present study, we conducted a series of experiments to determine the safety of the vaccine candidates in interferon regulatory factor-1-knockout (IRF-1(-/-)) mice. IRF-1(-/-) mice infected with either wild-type Brucella melitensis 16 M or the vaccine strain Brucella abortus S19 succumb to the disease within the first 3 weeks of infection, which is characterized by a marked granulomatous and neutrophilic inflammatory response that principally targets the spleen and liver. In contrast, IRF-1(-/-) mice inoculated with either the 16 MΔvjbR or S19ΔvjbR vaccine do not show any clinical or major pathological changes associated with vaccination. Additionally, when 16 MΔvjbR- or S19ΔvjbR-vaccinated mice are challenged with wild-type Brucella melitensis 16M, the degree of colonization in multiple organs, along with associated pathological changes, is significantly reduced. These findings not only demonstrate the safety and protective efficacy of the vjbR mutant in an immunocompromised mouse model but also suggest the participation of lesser-known mechanisms in protective immunity against brucellosis. PMID:22169089

  2. Development of an anti-endotoxin vaccine for sepsis.

    Science.gov (United States)

    Cross, Alan S

    2010-01-01

    Gram-negative bacterial lipopolysaccharide (LPS, endotoxin) is an important initiator of sepsis, a clinical syndrome that is a leading cause of death in intensive care units. Vaccines directed against core LPS structures that are widely conserved among Gram-negative bacteria (GNB) have been developed for the treatment and/or prevention of sepsis. Killed whole bacterial vaccines (E. coli O111:B4, J5 [Rc chemotype] mutant and S. minnesota, Re chemotype) protected mice against experimental sepsis. Human J5 immune antisera reduced the mortality from GNB sepsis in a large controlled clinical trial; however, subsequent clinical studies with antiendotoxin antibodies did not demonstrate protective efficacy in sepsis. Multiple clinical studies have since demonstrated a correlation between the level of circulating antibodies to LPS core and morbidity and mortality in different clinical settings. We therefore developed a subunit vaccine by combining detoxified J5 LPS (J5 dLPS) with the outer membrane protein (OMP) from group B N. meningitidis. This vaccine was highly efficacious in experimental models of sepsis and progressed to phase 1 clinical trial. While well-tolerated, this vaccine induced only 3-4-fold increases in anti-J5 dLPS antibody. Addition of the TLR9 agonist, oligodeoxynucleotide with a CpG motif, as adjuvant to the vaccine increased antibody levels in mice and the vaccine/CpG combination will progress to phase 1 human study. Additional vaccines in which the core glycolipid was either conjugated to carrier protein or incorporated into liposomes have been developed, but have not progressed to clinical trial. Should an antiendotoxin vaccine become available, a new immunization strategy directed towards distinct populations at risk will be required. PMID:20593272

  3. [Local Immune response in rabbits following enteral immunization with live attenuated bacterial Enterobacteriaceae vaccines].

    Science.gov (United States)

    Dentschev, W; Marinova, S; Sumerska, T; Nenkov, P; Koitschev, T; Trifonowa, A

    1980-01-01

    Streptomycin-dependent and inactivated Shigella flexneri 2a and Shigella sonnei strains were intra-intestinally applied to rabbits for immunisation. Rosette and plaque tests and well as indirect haemagglutination gave short-time secretion of low titres of specific copro-antibody, following monovaccines and bivaccines. High titres of secretory antibody were induced, depending on doses, by re-immunisation. No antigen competition was established. The localised immune response caused by Shigella live vaccines was found to be much stronger than that induced by inactivated vaccines PMID:6998404

  4. Malaria Vaccine Candidate Diversity Offers Challenges and Opportunities for Effective Vaccine Development

    Directory of Open Access Journals (Sweden)

    Kamal CHOWDHURY

    2009-06-01

    Full Text Available Malaria is one of the most deadly diseases caused by protozoan parasites of genus Plasmodium. It affects 300-500 million people annually, of which more than a million lives are lost; among them majority under 5 years of age. By conventional wisdom, the immune mechanisms responsible for protection against malaria will require a multiple of 10-15 antigen targets for proper protection against various stages of malarial infection. Such large number of targets cannot be delivered to humans, by this method. Moreover, each antigen is reported to be highly polymorphic in nature and the malaria-affected populations live in economically poor part of the world. Development of anti-malarial vaccines is therefore, a very tough challenge from technical, delivery and affordability points of view. Technical challenges include identification of epitopes / antigens against appropriate targets, construction of DNA vector(s that will express properly folded functional protein. Vaccine delivery challenges include developing an easy method to deliver multiple doses within a short period of time to infants and children of less than five years of age. Affordability challenges include development of cost-effective vaccines that can be stored at room temperature and be easily delivered. Although the complex life cycle of Plasmodium is challenging for anti-malarial vaccine development, it also offers a lot of antigen targets (opportunities to combat malaria. Information on anti-malarial vaccine candidates, DNA constructs and cost-effective delivery mechanism will be discussed.

  5. Hepatitis E vaccine development: a 14 year odyssey.

    Science.gov (United States)

    Wu, Ting; Li, Shao-Wei; Zhang, Jun; Ng, Mun-Hon; Xia, Ning-Shao; Zhao, Qinjian

    2012-06-01

    The first prophylactic vaccine, Hecolin®, against hepatitis E virus (HEV) infection and the HEV associated disease was approved by China's State Food and Drug Administration (SFDA) in December 2011. Key milestones during the 14-year HEV vaccine development are summarized in this commentary.  After years of innovative research the recombinant virus-like particle (VLP) based antigen with virion-like epitopes was successfully produced in E. coli production platform on a commercial scale. Safety and efficacy of this vaccine was demonstrated in a large scale phase III clinical trial. PMID:22699438

  6. Effects of the live attenuated measles-mumps-rubella booster vaccination on disease activity in patients with juvenile idiopathic arthritis : a randomized trial

    NARCIS (Netherlands)

    Heijstek, Marloes W; Kamphuis, Sylvia; Armbrust, Wineke; Swart, Joost; Gorter, Simone; de Vries, Lara D; Smits, Gaby P; van Gageldonk, Pieter G; Berbers, Guy A M; Wulffraat, Nico M

    2013-01-01

    IMPORTANCE: The immunogenicity and the effects of live attenuated measles-mumps-rubella (MMR) vaccination on disease activity in patients with juvenile idiopathic arthritis (JIA) are matters of concern, especially in patients treated with immunocompromising therapies. OBJECTIVES: To assess whether M

  7. [Progress in the development of vaccines against helminths].

    Science.gov (United States)

    Kozak, Monika; Kołodziej-Sobocińska, Marta

    2009-01-01

    Helminth infections are an important health problem for both humans and animals worldwide. The most sought for prophylactic strategy is vaccination due to the increasing incidence of anthelminthic resistance with little progress towards the discovery of novel drugs. However, the development of efficient anti-parasitic vaccines was proven to be a far greater challenge than in the case of bacteria or viruses. This is partly a result of the complex immunological interactions occurring during helminth infections, which are not yet fully understood, especially regarding the immune mechanisms conveying protection. Another problem is progressing from the research phase of vaccine development to commercial production and marketing. The advances made so far in developing efficient vaccines against helminth vary among the different classes, with a wide spectrum of both native and recombinant vaccine candidates. This review aims at presenting the current status and most important achievements in the field of helminth vaccine development, as well as the main obstacles and difficulties standing in the way of progress and practical applications. PMID:19670530

  8. Challenges and future in vaccines, drug development, and immunomodulatory therapy.

    Science.gov (United States)

    Kling, Heather M; Nau, Gerard J; Ross, Ted M; Evans, Thomas G; Chakraborty, Krishnendu; Empey, Kerry M; Flynn, JoAnne L

    2014-08-01

    Pulmonary diseases and infections are among the top contributors to human morbidity and mortality worldwide, and despite the successful history of vaccines and antimicrobial therapeutics, infectious disease still presents a significant threat to human health. Effective vaccines are frequently unavailable in developing countries, and successful vaccines have yet to be developed for major global maladies, such as tuberculosis. Furthermore, antibiotic resistance poses a growing threat to human health. The "Challenges and Future in Vaccines, Drug Development, and Immunomodulatory Therapy" session of the 2013 Pittsburgh International Lung Conference highlighted several recent and current studies related to treatment and prevention of antibiotic-resistant bacterial infections, highly pathogenic influenza, respiratory syncytial virus, and tuberculosis. Research presented here focused on novel antimicrobial therapies, new vaccines that are either in development or currently in clinical trials, and the potential for immunomodulatory therapies. These studies are making important contributions to the areas of microbiology, virology, and immunology related to pulmonary diseases and infections and are paving the way for improvements in the efficacy of vaccines and antimicrobials. PMID:25148426

  9. Development of a minimal saponin vaccine adjuvant based on QS-21

    Science.gov (United States)

    Fernández-Tejada, Alberto; Chea, Eric K.; George, Constantine; Pillarsetty, Nagavarakishore; Gardner, Jeffrey R.; Livingston, Philip O.; Ragupathi, Govind; Lewis, Jason S.; Tan, Derek S.; Gin, David Y.

    2014-07-01

    Adjuvants are materials added to vaccines to enhance the immunological response to an antigen. QS-21 is a natural product adjuvant under investigation in numerous vaccine clinical trials, but its use is constrained by scarcity, toxicity, instability and an enigmatic molecular mechanism of action. Herein we describe the development of a minimal QS-21 analogue that decouples adjuvant activity from toxicity and provides a powerful platform for mechanistic investigations. We found that the entire branched trisaccharide domain of QS-21 is dispensable for adjuvant activity and that the C4-aldehyde substituent, previously proposed to bind covalently to an unknown cellular target, is also not required. Biodistribution studies revealed that active adjuvants were retained preferentially at the injection site and the nearest draining lymph nodes compared with the attenuated variants. Overall, these studies have yielded critical insights into saponin structure-function relationships, provided practical synthetic access to non-toxic adjuvants, and established a platform for detailed mechanistic studies.

  10. Oral vaccination with inhibin DNA delivered using attenuated Salmonella choleraesuis for improving reproductive traits in mice.

    Science.gov (United States)

    Han, Li; Zhen, Yan-Hong; Liang, Ai-Xin; Zhang, Jian; Riaz, Hasan; Xiong, Jia-Jun; Guo, Ai-Zhen; Yang, Li-Guo

    2014-09-01

    The objective of this study was to examine the efficacy and safety of a novel inhibin vaccine containing inhibin α (1-32) fragments in mice. A recombinant plasmid pVAX-asd-IS was constructed by inserting recombinant inhibin α (1-32) and the hepatitis B surface antigen S into the plasmid in which the asd gene, rather than the kanamycin gene, was a selection marker. Ninety Kuming mice were divided into six groups consisting of 15 mice each. First group was (C1) injected with 200 µl of PBS, second (C2) received 1 × 10(10) CFU of crp(-) /asd(-) C500/pVAX-asd and served as vector control, third did not receive any treatment (C3), while fourth, fifth, and sixth group received 1 × 10(10) , 1 × 10(9) , 1 × 10(8) CFU of the recombinant inhibin vaccine crp(-) /asd(-) C500/pVAX-asd-IS (group T1, T2, T3), respectively. Western blotting demonstrated that recombinant expressed inhibin protein possessed immune function and that this plasmid could replicate for up to 40 generations stably. Vaccination with this strain at a dose of 1 × 10(10) CFU/200 µl per mouse induced high anti-inhibin antibody levels, significantly increased large-follicle production in T1 group (p  0.05) compared with control groups. Integration studies showed no evidence of inhibin fusion gene integrated into mice's genome 2-month after immunization. These results suggest that the vaccine described in the present study may provide a safe method to improve reproductive traits in animals. A trend towards increased litter size and significant increase in large follicle population depict that this vaccine may have direct application in large animal industry. PMID:24123188

  11. 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

  12. Latest developments and future directions in dengue vaccines

    OpenAIRE

    Thisyakorn, Usa; Thisyakorn, Chule

    2014-01-01

    Dengue is a mosquito-borne disease which is currently an expanding global health problem. The disease is caused by four closely related viruses, the dengue virus. There are no specific dengue therapeutics and prevention is currently limited to vector control measures. Development of an effective tetravalent dengue vaccine would therefore represent a major advance in the control of the disease and is considered a high public health priority. While a licensed dengue vaccine is not yet available...

  13. Development of Contagious Caprine Pleuropneumonia Inactivated Vaccine( M1601 Strain)

    Institute of Scientific and Technical Information of China (English)

    Zhao; Ping; He; Ying; Chu; Yuefeng; Gao; Pengcheng; Zhang; Xuan; Lu; Zhongxin

    2014-01-01

    Three batches of contagious caprine pleuropneumonia inactivated vaccine( M1601 strain) developed by the laboratory were studied from the aspects of safety,minimum immune dose,immunity duration and storage life. The results showed that the vaccine was safe to goats under different physiological conditions.Regardless of lambs or adult goats,the minimum immune dose was 3 m L,and the immunity duration and the storage life were 6 and 12 months,respectively.

  14. The search for animal models for Lassa fever vaccine development

    OpenAIRE

    Lukashevich, Igor S.

    2013-01-01

    Lassa virus (LASV) is the most prevalent arenavirus in West Africa and is responsible for several hundred thousand infections and thousands of deaths annually. The sizeable disease burden, numerous imported cases of Lassa fever (LF) and the possibility that LASV can be used as an agent of biological warfare make a strong case for vaccine development. Currently there is no licensed LF vaccine and research and devlopment is hampered by the high cost of nonhuman primate animal models and by bioc...

  15. Developing recombinant and synthetic vaccines for the treatment of melanoma

    OpenAIRE

    Restifo, Nicholas P; Rosenberg, Steven A.

    1999-01-01

    To develop new vaccines for the treatment of patients with cancer, target antigens presented on tumor cell surfaces have been cloned. Many of these antigens are non-mutated differentiation antigens and are expressed by virtually all melanomas, making them attractive components for a widely efficacious melanoma vaccine. These antigens are also expressed by melanocytes, however, and are likely to be subject to immune tolerance. A central challenge for tumor immunologists has thus been the break...

  16. Comparison of immune responses to intranasal and intrapulmonary vaccinations with the attenuated Mycoplasma hyopneumoniae 168 strain in pigs.

    Science.gov (United States)

    Li, Pengcheng; Li, Yunfeng; Shao, Guoqing; Yu, Qinghua; Yang, Qian

    2015-05-01

    The aim of this study was to evaluate the immune responses to intranasal and intrapulmonary vaccinations with the attenuated Mycoplasma hyopneumoniae (Mhp) 168 strain in the local respiratory tract in pigs. Twenty-four pigs were randomly divided into 4 groups: an intranasal immunization group, an intrapulmonary immunization group, an intramuscular immunization group and a control group. The levels of local respiratory tract cellular and humoral immune responses were investigated. The levels of interleukin (IL)-6 in the early stage of immunization (P<0.01), local specific secretory IgA (sIgA) in nasal swab samples (P<0.01); and IgA- and IgG-secreting cells in the nasal mucosa and trachea were higher after intranasal vaccination (P<0.01) than in the control group. Interestingly, intrapulmonary immunization induced much stronger immune responses than intranasal immunization. Intrapulmonary immunization also significantly increased the secretion of IL-6 and local specific sIgA and the numbers of IgA- and IgG-secreting cells. The levels of IL-10 and interferon-γ in the nasal swab samples and the numbers of CD4(+) and CD8(+) T lymphocytes in the lung and hilar lymph nodes were significantly increased by intrapulmonary immunization compared with those in the control group (P<0.01). These data suggest that intrapulmonary immunization with attenuated Mhp is effective in evoking local cellular and humoral immune responses in the respiratory tract. Intrapulmonary immunization with Mhp may be a promising route for defense against Mhp in pigs. PMID:25649413

  17. Design of clinical trials for therapeutic cancer vaccines development.

    Science.gov (United States)

    Mackiewicz, Jacek; Mackiewicz, Andrzej

    2009-12-25

    Advances in molecular and cellular biology as well as biotechnology led to definition of a group of drugs referred to as medicinal products of advanced technologies. It includes gene therapy products, somatic cell therapeutics and tissue engineering. Therapeutic cancer vaccines including whole cell tumor cells vaccines or gene modified whole cells belong to somatic therapeutics and/or gene therapy products category. The drug development is a multistep complex process. It comprises of two phases: preclinical and clinical. Guidelines on preclinical testing of cell based immunotherapy medicinal products have been defined by regulatory agencies and are available. However, clinical testing of therapeutic cancer vaccines is still under debate. It presents a serious problem since recently clinical efficacy of the number of cancer vaccines has been demonstrated that focused a lot of public attention. In general clinical testing in the current form is very expensive, time consuming and poorly designed what may lead to overlooking of products clinically beneficial for patients. Accordingly regulatory authorities and researches including Cancer Vaccine Clinical Trial Working Group proposed three regulatory solutions to facilitate clinical development of cancer vaccines: cost-recovery program, conditional marketing authorization, and a new development paradigm. Paradigm includes a model in which cancer vaccines are investigated in two types of clinical trials: proof-of-principle and efficacy. The proof-of-principle trial objectives are: safety; dose selection and schedule of vaccination; and demonstration of proof-of-principle. Efficacy trials are randomized clinical trials with objectives of demonstrating clinical benefit either directly or through a surrogate. The clinical end points are still under debate. PMID:19835869

  18. Role of nanotechnology in HIV/AIDS vaccine development.

    Science.gov (United States)

    Liu, Ying; Chen, Chunying

    2016-08-01

    HIV/AIDS is one of the worst crises affecting global health and influencing economic development and social stability. Preventing and treating HIV infection is a crucial task. However, there is still no effective HIV vaccine for clinical application. Nanotechnology has the potential to solve the problems associated with traditional HIV vaccines. At present, various nano-architectures and nanomaterials can function as potential HIV vaccine carriers or adjuvants, including inorganic nanomaterials, liposomes, micelles and polymer nanomaterials. In this review, we summarize the current progress in the use of nanotechnology for the development of an HIV/AIDS vaccine and discuss its potential to greatly improve the solubility, permeability, stability and pharmacokinetics of HIV vaccines. Although nanotechnology holds great promise for applications in HIV/AIDS vaccines, there are still many inadequacies that result in a variety of risks and challenges. The potential hazards to the human body and environment associated with some nano-carriers, and their underlying mechanisms require in-depth study. Non-toxic or low-toxic nanomaterials with adjuvant activity have been identified. However, studying the confluence of factors that affect the adjuvant activity of nanomaterials may be more important for the optimization of the dosage and immunization strategy and investigations into the exact mechanism of action. Moreover, there are no uniform standards for investigations of nanomaterials as potential vaccine adjuvants. These limitations make it harder to analyze and deduce rules from the existing data. Developing vaccine nano-carriers or adjuvants with high benefit-cost ratios is important to ensure their broad usage. Despite some shortcomings, nanomaterials have great potential and application prospects in the fields of AIDS treatment and prevention. PMID:26952542

  19. Constitutive expression of the Vi polysaccharide capsular antigen in attenuated Salmonella enterica serovar typhi oral vaccine strain CVD 909.

    Science.gov (United States)

    Wang, J Y; Noriega, F R; Galen, J E; Barry, E; Levine, M M

    2000-08-01

    Live oral Ty21a and parenteral Vi polysaccharide vaccines provide significant protection against typhoid fever, albeit by distinct immune mechanisms. Vi stimulates serum immunoglobulin G Vi antibodies, whereas Ty21a, which does not express Vi, elicits humoral and cell-mediated immune responses other than Vi antibodies. Protection may be enhanced if serum Vi antibody as well as cell-mediated and humoral responses can be stimulated. Disappointingly, several new attenuated Salmonella enterica serovar Typhi oral vaccines (e.g., CVD 908-htrA and Ty800) that elicit serum O and H antibody and cell-mediated responses following a single dose do not stimulate serum Vi antibody. Vi expression is regulated in response to environmental signals such as osmolarity by controlling the transcription of tviA in the viaB locus. To investigate if Vi antibodies can be stimulated if Vi expression is rendered constitutive, we replaced P(tviA) in serovar Typhi vaccine CVD 908-htrA with the constitutive promoter P(tac), resulting in CVD 909. CVD 909 expresses Vi even under high-osmolarity conditions and is less invasive for Henle 407 cells. In mice immunized with a single intranasal dose, CVD 909 was more immunogenic than CVD 908-htrA in eliciting serum Vi antibodies (geometric mean titer of 160 versus 49, P = 0.0007), whereas O antibody responses were virtually identical (geometric mean titer of 87 versus 80). In mice challenged intraperitoneally with wild-type serovar Typhi 4 weeks after a single intranasal immunization, the mortality of those immunized with CVD 909 (3 of 8) was significantly lower than that of control mice (10 of 10, P = 0.043) or mice given CVD 908-htrA (9 of 10, P = 0.0065). PMID:10899868

  20. Progress, challenges, and opportunities in Francisella vaccine development.

    Science.gov (United States)

    Elkins, Karen L; Kurtz, Sherry L; De Pascalis, Roberto

    2016-09-01

    Renewed interest in Francisella tularensis has resulted in substantial new information about its pathogenesis and immunology, along with development of useful animal models. While understanding of protective immunity against Francisella remains incomplete, data in both animals and humans suggest that inducing T cell-mediated immunity is crucial for successful vaccination with current candidates such as the Live Vaccine Strain (LVS), with specific antibodies and immune B cells playing supporting roles. Consistent with this idea, recent results indicate that measurements of T cell functions and relative gene expression by immune T cells predict vaccine-induced protection in animal models. Because field trials of new vaccines will be difficult to design, using such measurements to derive potential correlates of protection may be important to bridge between animal efficacy studies and people. PMID:27010448

  1. The search for animal models for Lassa fever vaccine development.

    Science.gov (United States)

    Lukashevich, Igor S

    2013-01-01

    Lassa virus (LASV) is the most prevalent arenavirus in West Africa and is responsible for several hundred thousand infections and thousands of deaths annually. The sizeable disease burden, numerous imported cases of Lassa fever (LF) and the possibility that LASV can be used as an agent of biological warfare make a strong case for vaccine development. Currently there is no licensed LF vaccine and research and devlopment is hampered by the high cost of nonhuman primate animal models and by biocontainment requirements (BSL-4). In addition, a successful LF vaccine has to induce a strong cell-mediated cross-protective immunity against different LASV lineages. All of these challenges will be addressed in this review in the context of available and novel animal models recently described for evaluation of LF vaccine candidates. PMID:23256740

  2. The search for animal models for Lassa fever vaccine development

    Science.gov (United States)

    Lukashevich, Igor S

    2013-01-01

    Lassa virus (LASV) is the most prevalent arenavirus in West Africa and is responsible for several hundred thousand infections and thousands of deaths annually. The sizeable disease burden, numerous imported cases of Lassa fever (LF) and the possibility that LASV can be used as an agent of biological warfare make a strong case for vaccine development. Currently there is no licensed LF vaccine and research and devlopment is hampered by the high cost of nonhuman primate animal models and by biocontainment requirements (BSL-4). In addition, a successful LF vaccine has to induce a strong cell-mediated cross-protective immunity against different LASV lineages. All of these challenges will be addressed in this review in the context of available and novel animal models recently described for evaluation of LF vaccine candidates. PMID:23256740

  3. Status of research and development of vaccines for enterovirus 71.

    Science.gov (United States)

    Reed, Zarifah; Cardosa, Mary Jane

    2016-06-01

    Although outbreaks of Hand, Foot, and Mouth Disease (HFMD) in young children have long been recognized worldwide, the occurrence of rare and life-threatening neurological, respiratory, and cardiac complications has propelled this common condition into the spotlight as a major public health problem in the affected countries. Various enteroviruses cause HFMD, but the severe complications have been mostly associated with enterovirus 71 (EV71). Medical treatment is supportive and measures to interrupt transmission have been challenging to implement. Preventive vaccines could have an important clinical impact, especially among children younger than 3 years old who are most susceptible to the neurological complications. Several groups in the highly affected Asia-Pacific region are working towards vaccines against EV71 and some candidates have progressed to late-stage clinical trials with two vaccines recently reported to have been approved by the regulatory authorities in China. This report summarizes current issues and progress in the development of vaccines against EV71. PMID:26973065

  4. Development of CpG ODN Based Vaccine Adjuvant Formulations.

    Science.gov (United States)

    Gursel, Mayda; Gursel, Ihsan

    2016-01-01

    Development of effective vaccine mediated immune responses relies on the use of vaccine adjuvants capable of enhancing and directing the adaptive immune response to the antigen. When used as vaccine adjuvants, type I interferon inducing agents can elicit potent effector/memory T cell responses and humoral immunity. Distinct sequences of single stranded synthetic oligodeoxynucleotides containing unmethylated cytosine-phosphate-guanine oligodeoxynucleotide motifs (CpG ODN) can generate type I interferon production via a TLR9-MyD88-IRF7-mediated signaling pathway. Here, we describe two different methods of preparing CpG ODN-based vaccine adjuvant formulations that can induce a robust IFNα response from human peripheral blood mononuclear cells. PMID:27076306

  5. POTENTIAL OF Salmonella typhi ATTENUATED WITH ULTRAVIOLET RAYS AS VACCINE ALTERNATIVE

    Directory of Open Access Journals (Sweden)

    Andreas Putro Ragil Santoso

    2016-03-01

    Full Text Available Salmonella typhi is a Gram-negative intracellular bacterium and causes typhoid fever in humans. The success rate of Berma Vivotif Ty21a vaccine in Indonesia is only 33-66%, while in other countries have been reached up to 100%. The research was conducted in order to determine the potency of local isolate bacteria to stimulate the immune response and the impact of different exposure frequencies on the immune response and the different immune response time when administered by UV-inactivated vaccine.. The results showed that the antibody titer of local isolates irradiated by UV light 10x was 88.76 ± 33.06 IU/mL at week 4 with the lowest antibody titer values about 11.15 ± 9.18 IU/mL was found in the negative control

  6. Advances and challenges in malaria vaccine development

    OpenAIRE

    Wang, Ruobing; Smith, Joseph D.; Kappe, Stefan H.I.

    2010-01-01

    Malaria remains one of the most devastating infectious diseases that threaten humankind. Human malaria is caused by five different species of Plasmodium parasites, each transmitted by the bite of female Anopheles mosquitoes. Plasmodia are eukaryotic protozoans with more than 5000 genes and a complex life cycle that takes place in the mosquito vector and the human host. The life cycle can be divided into pre-erythrocytic stages, erythrocytic stages and mosquito stages. Malaria vaccine research...

  7. Immunopathological and pathological consequences in mice vaccinated with radiation-attenuated blood stages of Plasmodium berghei

    International Nuclear Information System (INIS)

    The protective effect, histopathology, immunopathology and serology of mice after vaccination with irradiated P. berghei before and after challenge with the blood stage of P. berghei were studied. The results showed that the mortality rates, as well as histopathological findings, in the liver, spleen and kidney may indicate an untoward immunological reaction, resulting in death during the first week after challenge in some immunized animals. The exact mechanisms are currently not known

  8. Evaluation of Three Live Attenuated H2 Pandemic Influenza Vaccine Candidates in Mice and Ferrets

    OpenAIRE

    Chen, Grace L.; Lamirande, Elaine W.; Cheng, Xing; Torres-Velez, Fernando; Orandle, Marlene; Jin, Hong; Kemble, George; Subbarao, Kanta

    2014-01-01

    H2 influenza viruses have not circulated in humans since 1968, and therefore a significant portion of the population would be susceptible to infection should H2 influenza viruses reemerge. H2 influenza viruses continue to circulate in avian reservoirs worldwide, and these reservoirs are a potential source from which these viruses could emerge. Three reassortant cold-adapted (ca) H2 pandemic influenza vaccine candidates with hemagglutinin (HA) and neuraminidase (NA) genes derived from the wild...

  9. Mumps caused by an inadequately attenuated measles, mumps and rubella vaccine

    OpenAIRE

    Bakker, WJ; Mathias, RG

    2001-01-01

    PROBLEM: Reports of mumps following measles, mumps and rubella (MMR) immunization.OBJECTIVE: To determine whether mumps was caused by immunization or whether there was a concurrent epidemic of a wild strain of mumps.DESIGN AND PARTICIPANTS: Analysis of surveillance data and a cohort study of three schools that participated in the campaign.OUTCOME MEASURES: Cases of clinical mumps and orchitis, and immunization history and records were reviewed. The MMR vaccine was produced by the Serum Instit...

  10. Development of recombinant vaccines for botulinum neurotoxin.

    Science.gov (United States)

    Smith, L A

    1998-11-01

    Synthetic genes encoding non-toxic, carboxyl-terminal regions (approximately 50 kDa) of botulinum neurotoxin (BoNT) serotypes A and B (referred to as fragment C or HC) were constructed and cloned into the methylotropic yeast, Pichia pastoris. Genes specifying BoNTA(HC) and BoNTB(HC) were expressed as both intracellular and secreted products. Recombinants, expressed intracellularly, yielded products with the expected molecular weight as judged by SDS PAGE and Western blot (immunoblot) analysis, while secreted products were larger due to glycosylation. Gene products were used to vaccinate mice and evaluated for their ability to elicit protective antibody titers in vivo. Mice given three intramuscular vaccinations with yeast supernatant containing glycosylated BoNTA(HC) were protected against an intraperitoneal challenge of 10(6) 50% mouse lethal doses (MLD50) of serotype A neurotoxin, a result not duplicated by its BoNTB(HC) counterpart. Vaccinating mice with cytoplasmically produced BoNTA(HC) and BoNTB(HC) protected animals from a challenge of 10(6) MLD50 of serotype A and B toxins, respectively. Because of the glycosylation encountered with secreted BoNT(HC), our efforts focused on the production and purification of products from intracellular expression. PMID:9792170

  11. Delta-pgm, a new live-attenuated vaccine against Brucella suis.

    Science.gov (United States)

    Czibener, Cecilia; Del Giudice, Mariela Giselda; Spera, Juan Manuel; Fulgenzi, Fabiana Rosa; Ugalde, Juan Esteban

    2016-03-18

    Brucellosis is one of the most widespread zoonosis in the world affecting many domestic and wild animals including bovines, goats, pigs and dogs. Each species of the Brucella genus has a particular tropism toward different mammals being the most relevant for human health Brucella abortus, Brucella melitensis and Brucella suis that infect bovines, goats/camelids and swine respectively. Although for B. abortus and B. melitensis there are vaccines available, there is no efficient vaccine to protect swine from B. suis infection so far. We describe here the construction of a novel vaccine strain that confers excellent protection against B. suis in a mouse model of infection. This strain is a clean deletion of the phosphoglucomutase (pgm) gene that codes for a protein that catalyzes the conversion of glucose-6-P to glucose-1-P, which is used as a precursor for the biosynthesis of many polysaccharides. The Delta-pgm strain lacks a complete lipopolysaccharide, is unable to synthesize cyclic beta glucans and is sensitive to several detergents and Polymyxin B. We show that this strain replicates in cultured cells, is completely avirulent in the mouse model of infection but protects against a challenge of the virulent strain inducing the production of pro-inflammatory cytokines. This novel strain could be an excellent candidate for the control of swine brucellosis, a disease of emerging concern in many parts of the world. PMID:26899373

  12. Immune systems in developed and developing countries; implications for the design of vaccines that will work where BCG does not.

    Science.gov (United States)

    Rook, Graham A W; Dheda, Keertan; Zumla, Alimuddin

    2006-01-01

    New vaccine candidates for tuberculosis are beginning to enter clinical trials. In this review we discuss issues surrounding the design of these candidates, and the way they were screened in animal models. First, screening vaccines for their ability to attenuate inevitably fatal tuberculosis in immunologically naïve mice might be leading to the selection of inappropriate candidates. We need to screen vaccines for their ability to stop the development of progressive disease, since this is what they must achieve in man. A solution to this problem is proposed. Secondly, we point out that some mouse models of tuberculosis in laboratories in developing countries, where exposure to environmental mycobacteria is large, mimic neglected aspects of human disease more closely than do low-dose infections in hyper-susceptible immunologically naïve mice in the USA or Europe. We need to think more about geographical differences in immunological experience, and these mouse models can help us. Thirdly, we conclude that in developing countries where BCG fails this is not because there is too little Th1 response, but rather because the Th1 response is rendered ineffective and immunopathological by other subversive mechanisms, including IL-4 responses and inappropriate regulatory T cell function. Therefore, we suggest that vaccines that will work in those countries might need to have immunoregulatory properties that can switch off pre-existing subversive mechanisms, and block their development in the future. The development of such vaccines, that might work where BCG does not, will require a greater understanding of the roles of the many types of regulatory T cell in tuberculosis. PMID:16510309

  13. Approaches to improve development methods for therapeutic cancer vaccines.

    Science.gov (United States)

    Ogi, Chizuru; Aruga, Atsushi

    2015-04-01

    Therapeutic cancer vaccines are an immunotherapy that amplify or induce an active immune response against tumors. Notably, limitations in the methodology for existing anti-cancer drugs may subsist while applying them to cancer vaccine therapy. A retrospective analysis was performed using information obtained from ClinicalTrials.gov, PubMed, and published articles. Our research evaluated the optimal methodologies for therapeutic cancer vaccines based on (1) patient populations, (2) immune monitoring, (3) tumor response evaluation, and (4) supplementary therapies. Failure to optimize these methodologies at an early phase may impact development at later stages; thus, we have proposed some points to be considered during the early phase. Moreover, we compared our proposal with the guidance for industry issued by the US Food and Drug Administration in October 2011 entitled "Clinical Considerations for Therapeutic Cancer Vaccines". Consequently, while our research was aligned with the guidance, we hope it provides further insights in order to predict the risks and benefits and facilitate decisions for a new technology. We identified the following points for consideration: (1) include in the selection criteria the immunological stage with a prognostic value, which is as important as the tumor stage; (2) select immunological assays such as phenotype analysis of lymphocytes, based on their features and standardize assay methods; (3) utilize optimal response criteria for immunotherapy in therapeutic cancer vaccine trials; and (4) consider supplementary therapies, including immune checkpoint inhibitors, for future therapeutic cancer vaccines. PMID:25746315

  14. Development of a Vaccine against Escherichia coli Urinary Tract Infections.

    Science.gov (United States)

    Mobley, Harry L T; Alteri, Christopher J

    2015-01-01

    Urinary tract infection (UTI) is the second most common infection in humans after those involving the respiratory tract. This results not only in huge annual economic costs, but in decreased workforce productivity and high patient morbidity. Most infections are caused by uropathogenic Escherichia coli (UPEC). Antibiotic treatment is generally effective for eradication of the infecting strain; however, documentation of increasing antibiotic resistance, allergic reaction to certain pharmaceuticals, alteration of normal gut flora, and failure to prevent recurrent infections represent significant barriers to treatment. As a result, approaches to prevent UTI such as vaccination represent a gap that must be addressed. Our laboratory has made progress toward development of a preventive vaccine against UPEC. The long-term research goal is to prevent UTIs in women with recurrent UTIs. Our objective has been to identify the optimal combination of protective antigens for inclusion in an effective UTI vaccine, optimal adjuvant, optimal dose, and optimal route of delivery. We hypothesized that a multi-subunit vaccine elicits antibody that protects against experimental challenge with UPEC strains. We have systematically identified four antigens that can individually protect experimentally infected mice from colonization of the bladder and/or kidneys by UPEC when administered intranasally with cholera toxin (CT) as an adjuvant. To advance the vaccine for utility in humans, we will group the individual antigens, all associated with iron acquisition (IreA, Hma, IutA, FyuA), into an effective combination to establish a multi-subunit vaccine. We demonstrated for all four vaccine antigens that antigen-specific serum IgG represents a strong correlate of protection in vaccinated mice. High antibody titers correlate with low colony forming units (CFUs) of UPEC following transurethral challenge of vaccinated mice. However, the contribution of cell-mediated immunity cannot be ruled out and

  15. Safety Overview of a Recombinant Live-Attenuated Tetravalent Dengue Vaccine: Pooled Analysis of Data from 18 Clinical Trials.

    Directory of Open Access Journals (Sweden)

    Sophia Gailhardou

    2016-07-01

    Full Text Available A recombinant live attenuated tetravalent dengue vaccine (CYD-TDV has been shown to be efficacious in preventing virologically-confirmed dengue disease, severe dengue disease and dengue hospitalization in children aged 2-16 years in Asia and Latin America. We analyzed pooled safety data from 18 phase I, II and III clinical trials in which the dengue vaccine was administered to participants aged 2-60 years, including long-term safety follow-up in three efficacy trials. The participants were analyzed according to their age at enrollment. The percentage of participants aged 2-60 years reporting ≥1 solicited injection-site or systemic reactions was slightly higher in the CYD-TDV group than in the placebo group. The most common solicited injection-site reactions were pain. Headache and malaise were the most common solicited systemic reactions. In both groups 0.3% of participants discontinued for safety reasons. The most common unsolicited adverse events were injection-site reactions, gastrointestinal disorders, and infections. Reactogenicity did not increase with successive doses of CYD-TDV. The frequency and nature of SAEs occurring within 28 days of any dose were similar in the CYD-TDV and placebo groups and were common medical conditions that could be expected as a function of age. Baseline dengue virus serostatus did not appear to influence the safety profile. No vaccine-related anaphylactic reactions, neurotropic events or viscerotropic events were reported. In year 3 after dose 1, an imbalance for dengue hospitalization, including for severe dengue, observed in participants aged <9 years in the CYD-TDV group compared with the placebo group was not observed for participants aged ≥9 years. In Year 4, this imbalance in participants aged <9 years was less marked, giving an overall lower risk of dengue hospitalization or severe dengue from dose 1 to Year 4 in the CYD-TDV group. These results have contributed to the definition of the target

  16. Safety Overview of a Recombinant Live-Attenuated Tetravalent Dengue Vaccine: Pooled Analysis of Data from 18 Clinical Trials.

    Science.gov (United States)

    Gailhardou, Sophia; Skipetrova, Anna; Dayan, Gustavo H; Jezorwski, John; Saville, Melanie; Van der Vliet, Diane; Wartel, T Anh

    2016-07-01

    A recombinant live attenuated tetravalent dengue vaccine (CYD-TDV) has been shown to be efficacious in preventing virologically-confirmed dengue disease, severe dengue disease and dengue hospitalization in children aged 2-16 years in Asia and Latin America. We analyzed pooled safety data from 18 phase I, II and III clinical trials in which the dengue vaccine was administered to participants aged 2-60 years, including long-term safety follow-up in three efficacy trials. The participants were analyzed according to their age at enrollment. The percentage of participants aged 2-60 years reporting ≥1 solicited injection-site or systemic reactions was slightly higher in the CYD-TDV group than in the placebo group. The most common solicited injection-site reactions were pain. Headache and malaise were the most common solicited systemic reactions. In both groups 0.3% of participants discontinued for safety reasons. The most common unsolicited adverse events were injection-site reactions, gastrointestinal disorders, and infections. Reactogenicity did not increase with successive doses of CYD-TDV. The frequency and nature of SAEs occurring within 28 days of any dose were similar in the CYD-TDV and placebo groups and were common medical conditions that could be expected as a function of age. Baseline dengue virus serostatus did not appear to influence the safety profile. No vaccine-related anaphylactic reactions, neurotropic events or viscerotropic events were reported. In year 3 after dose 1, an imbalance for dengue hospitalization, including for severe dengue, observed in participants aged dengue hospitalization or severe dengue from dose 1 to Year 4 in the CYD-TDV group. These results have contributed to the definition of the target population for vaccination (≥9 years old) for which CYD-TDV has a satisfactory safety profile. Long-term safety will continue to be monitored in the ongoing follow-up of efficacy trials. Safety and effectiveness in real-life settings will

  17. Japanese encephalitis vaccines: current vaccines and future prospects.

    Science.gov (United States)

    Monath, T P

    2002-01-01

    Vaccination against JE ideally should be practiced in all areas of Asia where the virus is responsible for human disease. The WHO has placed a high priority on the development of a new vaccine for prevention of JE. Some countries in Asia (Japan, South Korea, North Korea, Taiwan, Vietnam, Thailand, and the PRC) manufacture JE vaccines and practice childhood immunization, while other countries suffering endemic or epidemic disease (India, Nepal, Laos, Cambodia, Bangladesh, Myanmar, Malaysia, Indonesia and the Philippines) have no JE vaccine manufacturing or policy for use. With the exception of the PRC, all countries practicing JE vaccination use formalin inactivated mouse brain vaccines, which are relatively expensive and are associated with rare but clinically significant allergic and neurological adverse events. New inactivated JE vaccines manufactured in Vero cells are in advanced preclinical or early clinical development in Japan, South Korea, Taiwan, and the PRC. An empirically derived, live attenuated vaccine (SA14-14-2) is widely used in the PRC. Trials in the PRC have shown SA14-14-2 to be safe and effective when administered in a two-dose regimen, but regulatory concerns over manufacturing and control have restricted international distribution. The genetic basis of attenuation of SA14-14-2 has been partially defined. A new live attenuated vaccine (ChimeriVax-JE) that uses a reliable flavivirus vaccine--yellow fever 17D--as a live vector for the envelope genes of SA14-14-2 virus is in early clinical trials and appears to be well tolerated and immunogenic after a single dose. Vaccinia and avipox vectored vaccines have also been tested clinically, but are no longer being pursued due to restricted effectiveness mediated by anti-vector immunity. Other approaches to JE vaccines--including naked DNA, oral vaccination, and recombinant subunit vaccines--have been reviewed. PMID:12082985

  18. Long-Term Safety and Immunogenicity of a Tetravalent Live-Attenuated Dengue Vaccine and Evaluation of a Booster Dose Administered to Healthy Thai Children.

    Science.gov (United States)

    Watanaveeradej, Veerachai; Simasathien, Sriluck; Mammen, Mammen P; Nisalak, Ananda; Tournay, Elodie; Kerdpanich, Phirangkul; Samakoses, Rudiwilai; Putnak, Robert J; Gibbons, Robert V; Yoon, In-Kyu; Jarman, Richard G; De La Barrera, Rafael; Moris, Philippe; Eckels, Kenneth H; Thomas, Stephen J; Innis, Bruce L

    2016-06-01

    We evaluated the safety and immunogenicity of two doses of a live-attenuated, tetravalent dengue virus vaccine (F17/Pre formulation) and a booster dose in a dengue endemic setting in two studies. Seven children (7- to 8-year-olds) were followed for 1 year after dose 2 and then given a booster dose (F17/Pre formulation), and followed for four more years (Child study). In the Infant study, 49 2-year-olds, vaccinated as infants, were followed for approximately 3.5 years after dose 2 and then given a booster dose (F17) and followed for one additional year. Two clinically notable events were observed, both in dengue vaccine recipients in the Infant study: 1 case of dengue approximately 2.7 years after dose 2 and 1 case of suspected dengue after booster vaccinations. The booster vaccinations had a favorable safety profile in terms of reactogenicity and adverse events reported during the 1-month follow-up periods. No vaccine-related serious adverse events were reported during the studies. Neutralizing antibodies against dengue viruses 1-4 waned during the 1-3 years before boosting, which elicited a short-lived booster response but did not provide a long-lived, multivalent antibody response in most subjects. Overall, this candidate vaccine did not elicit a durable humoral immune response. PMID:27022153

  19. Long-Term Safety and Immunogenicity of a Tetravalent Live-Attenuated Dengue Vaccine and Evaluation of a Booster Dose Administered to Healthy Thai Children

    Science.gov (United States)

    Watanaveeradej, Veerachai; Simasathien, Sriluck; Mammen, Mammen P.; Nisalak, Ananda; Tournay, Elodie; Kerdpanich, Phirangkul; Samakoses, Rudiwilai; Putnak, Robert J.; Gibbons, Robert V.; Yoon, In-Kyu; Jarman, Richard G.; De La Barrera, Rafael; Moris, Philippe; Eckels, Kenneth H.; Thomas, Stephen J.; Innis, Bruce L.

    2016-01-01

    We evaluated the safety and immunogenicity of two doses of a live-attenuated, tetravalent dengue virus vaccine (F17/Pre formulation) and a booster dose in a dengue endemic setting in two studies. Seven children (7- to 8-year-olds) were followed for 1 year after dose 2 and then given a booster dose (F17/Pre formulation), and followed for four more years (Child study). In the Infant study, 49 2-year-olds, vaccinated as infants, were followed for approximately 3.5 years after dose 2 and then given a booster dose (F17) and followed for one additional year. Two clinically notable events were observed, both in dengue vaccine recipients in the Infant study: 1 case of dengue approximately 2.7 years after dose 2 and 1 case of suspected dengue after booster vaccinations. The booster vaccinations had a favorable safety profile in terms of reactogenicity and adverse events reported during the 1-month follow-up periods. No vaccine-related serious adverse events were reported during the studies. Neutralizing antibodies against dengue viruses 1–4 waned during the 1–3 years before boosting, which elicited a short-lived booster response but did not provide a long-lived, multivalent antibody response in most subjects. Overall, this candidate vaccine did not elicit a durable humoral immune response. PMID:27022153

  20. A Live Attenuated Vaccine for Lassa Fever Made by Reassortment of Lassa and Mopeia Viruses

    OpenAIRE

    Lukashevich, Igor S.; Patterson, Jean; Carrion, Ricardo; Moshkoff, Dmitry; Ticer, Anysha; Zapata, Juan; Brasky, Kathleen; Geiger, Robert; Gene B Hubbard; Bryant, Joseph; Salvato, Maria S.

    2005-01-01

    Lassa virus (LASV) and Mopeia virus (MOPV) are closely related Old World arenaviruses that can exchange genomic segments (reassort) during coinfection. Clone ML29, selected from a library of MOPV/LASV (MOP/LAS) reassortants, encodes the major antigens (nucleocapsid and glycoprotein) of LASV and the RNA polymerase and zinc-binding protein of MOPV. Replication of ML29 was attenuated in guinea pigs and nonhuman primates. In murine adoptive-transfer experiments, as little as 150 PFU of ML29 induc...

  1. Prevention and control of influenza and dengue through vaccine development.

    Science.gov (United States)

    Greenberg, David P; Robertson, Corwin A; Gordon, Daniel M

    2013-08-01

    Influenza and dengue are viral illnesses of global public health importance, especially among children. Accordingly, these diseases have been the focus of efforts to improve their prevention and control. Influenza vaccination offers the best protection against clinical disease caused by strains contained within the specific year's formulation. It is not uncommon for there to be a mismatch between vaccine strains and circulating strains, particularly with regards to the B lineages. For more than a decade, two distinct lineages of influenza B (Yamagata and Victoria) have co-circulated in the US with varying frequencies, but trivalent influenza vaccines contain only one B-lineage strain and do not offer adequate protection against the alternate B-lineage. Quadrivalent influenza vaccines (QIVs), containing two A strains (H1N1 and H3N2) and two B strains (one from each lineage) have been developed to help protect against the four strains predicted to be the most likely to be circulating. The QIV section of this article discusses epidemiology of pediatric influenza, importance of influenza B in children, potential benefits of QIV, and new quadrivalent vaccines. In contrast to influenza, a vaccine against dengue is not yet available in spite of many decades of research and development. A global increase in reports of dengue fever (DF) and its more severe presentations, dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS), suggest that US physicians will increasingly encounter patients with this disease. Similarities of the early signs and symptoms of influenza and dengue and the differences in disease management necessitates a better understanding of the epidemiology, clinical presentation, management, and prevention of DF by US physicians, including pediatricians. The article also provides a brief overview of dengue and discusses dengue vaccine development. PMID:23910031

  2. Dengue:epidemiology, prevention and pressing need for vaccine development

    Institute of Scientific and Technical Information of China (English)

    Kuldeep Kumar; Pankaj Kumar Singh; Juhi Tomar; Swati Baijal

    2010-01-01

    Dengue fever is a mosquito born viral infection, and the complicated form of dengue is dengue hemorrhagic fever (DHF). In the recent decades incidence and distribution of dengue has increased dramatically. Dengue viruses belong to family flaviviridae with four serotypes and are transmitted mainly by mosquito Aedes aegypti. Today almost two-fifth of world's population (2.5 million) is at risk of dengue and no specific antiviral drug or vaccine is available against it. Uncontrolled population growth in Africa and South East Asia has increased number of susceptible hosts in urban and semi urban areas. About 40% of world population resides in the high risk area for dengue transmission. According to latest estimates by WHO, yearly 50 to 100 million infections occur globally, this includes around 500 000 DHF and 22 000 deaths, mostly among children. Only symptomatic treatment in the form of analgesic, antipyretics and body fluid management is provided to the patient. Prevention strategies mainly focus on two approaches, firstly on activities to control vector and secondly on activities to protect human from mosquito bite but there is always concerns regarding their sustainably and effectiveness. Theoretically development of an effective dengue vaccine is feasible and production of an effective and affordable vaccine could be a viable option to save humans from this dreadful disease. Conceptually vaccine production is possible, but it has to be tetravalent, providing immunity against all serotypes. Few candidate vaccines are in advance stage of their development; however international cooperation is needed to make these vaccines available on cheaper rates to the poor and vulnerable countries. Objective of this review is to discuss various aspects related to dengue, its epidemiology, available preventive methods, need for vaccine and challenges in its development.

  3. Progress and Challenges toward the Development of Vaccines against Avian Infectious Bronchitis

    Directory of Open Access Journals (Sweden)

    Faruku Bande

    2015-01-01

    Full Text Available Avian infectious bronchitis (IB is a widely distributed poultry disease that has huge economic impact on poultry industry. The continuous emergence of new IBV genotypes and lack of cross protection among different IBV genotypes have been an important challenge. Although live attenuated IB vaccines remarkably induce potent immune response, the potential risk of reversion to virulence, neutralization by the maternal antibodies, and recombination and mutation events are important concern on their usage. On the other hand, inactivated vaccines induce a weaker immune response and may require multiple dosing and/or the use of adjuvants that probably have potential safety risks and increased economic burdens. Consequently, alternative IB vaccines are widely sought. Recent advances in recombinant DNA technology have resulted in experimental IB vaccines that show promise in antibody and T-cells responses, comparable to live attenuated vaccines. Recombinant DNA vaccines have also been enhanced to target multiple serotypes and their efficacy has been improved using delivery vectors, nanoadjuvants, and in ovo vaccination approaches. Although most recombinant IB DNA vaccines are yet to be licensed, it is expected that these types of vaccines may hold sway as future vaccines for inducing a cross protection against multiple IBV serotypes.

  4. Gene-based vaccine development for improving animal production in developing countries. Possibilities and constraints

    International Nuclear Information System (INIS)

    For vaccine production, recombinant antigens must be protective. Identifying protective antigens or candidate antigens is an essential precursor to vaccine development. Even when a protective antigen has been identified, cloning of its gene does not lead directly to vaccine development. The fimbrial protein of Dichelobacter nodosus, the agent of foot-rot in ruminants, was known to be protective. Recombinant vaccines against this infection are ineffective if expressed protein subunits are not assembled as mature fimbriae. Antigenic competition between different, but closely related, recombinant antigens limited the use of multivalent vaccines based on this technology. Recombinant antigens may need adjuvants to enhance response. DNA vaccines, potentiated with genes for different cytokines, may replace the need for aggressive adjuvants, and especially where cellular immunity is essential for protection. The expression of antigens from animal pathogens in plants and the demonstration of some immunity to a disease like rinderpest after ingestion of these, suggests an alternative approach to vaccination by injection. Research on disease pathogenesis and the identification of candidate antigens is specific to the disease agent. The definition of expression systems and the formulation of a vaccine for each disease must be followed by research to establish safety and efficacy. Where vaccines are based on unique gene sequences, the intellectual property is likely to be protected by patent. Organizations, licensed to produce recombinant vaccines, expect to recover their costs and to make a profit. The consequence is that genetically-derived vaccines are expensive. The capacity of vaccines to help animal owners of poorer countries depends not only on quality and cost but also on the veterinary infrastructure where they are used. Ensuring the existence of an effective animal health infrastructure in developing countries is as great a challenge for the developed world as

  5. An alternative and effective HIV vaccination approach based on inhibition of antigen presentation attenuators in dendritic cells.

    OpenAIRE

    Xiao-Tong Song; Kevin Evel-Kabler; Lisa Rollins; Melissa Aldrich; Feng Gao; Xue F Huang; Si-Yi Chen

    2006-01-01

    BACKGROUND: Current efforts to develop HIV vaccines that seek to stimulate immune responses have been disappointing, underscoring the inability of natural immune responses to control HIV-1 infection. Here we tested an alternative strategy to induce anti-HIV immune responses by inhibiting a host's natural immune inhibitor. METHODS AND FINDINGS: We used small interfering RNA (siRNA) to inhibit suppressor of cytokine signaling (SOCS) 1, a key negative regulator of the JAK/STAT pathway, and inves...

  6. Characteristics of Memory B Cells Elicited by a Highly Efficacious HPV Vaccine in Subjects with No Pre-existing Immunity

    OpenAIRE

    Scherer, Erin M.; Smith, Robin A; Simonich, Cassandra A.; Niyonzima, Nixon; Carter, Joseph J.; Galloway, Denise A.

    2014-01-01

    Author Summary There is an urgent need to better understand how to reliably generate effective vaccines, particularly subunit vaccines, as certain pathogens are considered to pose too great of a safety risk to be developed as live, attenuated or killed vaccines (e.g., HIV-1). The human papillomavirus (HPV) vaccines are two of the most effective subunit vaccines ever developed and have continued to show protection against HPV associated disease up to and beyond five years post-vaccination. Mor...

  7. Proteomic analysis of Brucella abortus cell envelope and identification of immunogenic candidate proteins for vaccine development.

    Science.gov (United States)

    Connolly, Joseph P; Comerci, Diego; Alefantis, Timothy G; Walz, Alexander; Quan, Marian; Chafin, Ryan; Grewal, Paul; Mujer, Cesar V; Ugalde, Rodolfo A; DelVecchio, Vito G

    2006-07-01

    Brucella abortus is the etiologic agent of bovine brucellosis and causes a chronic disease in humans known as undulant fever. In livestock the disease is characterized by abortion and sterility. Live, attenuated vaccines such as S19 and RB51 have been used to control the spread of the disease in animals; however, they are considered unsafe for human use and they induce abortion in pregnant cattle. For the development of a safer and equally efficacious vaccine, immunoproteomics was utilized to identify novel candidate proteins from B. abortus cell envelope (CE). A total of 163 proteins were identified using 2-DE with MALDI-TOF MS and LC-MS/MS. Some of the major protein components include outer-membrane protein (OMP) 25, OMP31, Omp2b porin, and 60 kDa chaperonin GroEL. 2-DE Western blot analyses probed with antiserum from bovine and a human patient infected with Brucella identified several new immunogenic proteins such as fumarate reductase flavoprotein subunit, F0F1-type ATP synthase alpha subunit, and cysteine synthase A. The elucidation of the immunome of B. abortus CE identified a number of candidate proteins for developing vaccines against Brucella infection in bovine and humans. PMID:16739129

  8. Development of marker vaccines for rinderpest virus using reverse genetics technology

    International Nuclear Information System (INIS)

    Full text: Rinderpest or 'cattle plague' is an economically devastating disease which is still endemic in areas of Eastern Africa, its aetiological agent being a morbillivirus (RPV) closely related to human Measles virus. A global rinderpest eradication programme (GREP) is in place and its goal is the eradication of the disease by the year 2010. In the final stages of the eradication campaign, when mass vaccination must be discontinued, it would be desirable to use a vaccine that enables vaccinated animals to be distinguished from animals which have recovered from natural infection, so called 'marker vaccines'. These are now being produced using reverse genetics, the process whereby the genomes of RNA viruses can be genetically manipulated through a DNA copy and live virus rescued from the altered DNA. This very powerful new technology, in addition to its practical usefulness in allowing the development of marker vaccines, also enables us to investigate, on a rational scientific basis, the molecular determinants of virulence and attenuation in this virus group. This will be an important consideration when assessing the safety of such vaccines for general use. Reverse genetics for RPV was established in the Pirbright laboratory some six years ago and several candidate marker vaccines have been produced which are now ready for field testing. The first approach we have taken was to place genes encoding 'positive' marker proteins into the RPV genome. The markers chosen were the green fluorescent protein (GFP) and a modified form of the influenza haemagglutinin (fluHA) protein. A strong antibody response was generated to the fluHA marker protein in all animals vaccinated with the RPV-fluHA recombinant. The GFP gene was modified so that the protein, in addition to cytoplasmic expression, would be either secreted from the infected cells or expressed as a membrane anchored protein of the cell surface. The antibody response to the GFP protein elicited in the vaccinated

  9. Schistosomiasis vaccine development: progress and prospects

    Directory of Open Access Journals (Sweden)

    Bergquist NR

    1998-01-01

    Full Text Available The undisputed, worldwide success of chemotherapy notwithstanding, schistosomiasis continues to defy control efforts in as much rapid reinfection demands repeated treatment, sometimes as often as once a year. There is thus a need for a complementary tool with effect for the longer term, notably a vaccine. International efforts in this direction have been ongoing for several decades but, until the recombinant DNA techniques were introduced, antigen production remained an unsurmountable bottleneck. Although animal experiments have been highly productive and are still much needed, they probably do not reflect the human situation adequately and real progress can not be expected until more is known about human immune responses to schistosome infection. It is well-known that irradiated cercariae consistently produce high levels of protection in experimental animals but, for various reasons, this proof of principle cannot be directly exploited. Research has instead been focussed on the identification and testing of specific schistosome antigens. This work has been quite successful and is already at the stage where clinical trials are called for. Preliminary results from coordinated in vitro laboratory and field epidemiological studies regarding the protective potential of several antigens support the initiation of such trials. A series of meetings, organized earlier this year in Cairo, Egypt, reviewed recent progress, selecteded suitable vaccine candidates and made firm recommendations for future action including pledging support for large-scale production according to good manufacturing practice (GMP and Phase I trials. Scientists at the American Centers for Disease Control and Prevention (CDC have drawn up a detailed research plan. The major financial support will come from USAID, Cairo, which has established a scientific advisory group of Egyptian scientists and representatives from current and previous international donors such as WHO, NIAID, the

  10. Alumina-encapsulated vaccine formulation with improved thermostability and immunogenicity.

    Science.gov (United States)

    Zhou, Hangyu; Wang, Guangchuan; Li, Xiao-Feng; Li, Yaling; Zhu, Shun-Ya; Qin, Cheng-Feng; Tang, Ruikang

    2016-05-11

    Developing vaccine formulations with excellent thermostability and immunogenicity remains a great challenge. By in situ encapsulating a live-attenuated strain of human enterovirus 71 (EV71) in alumina, we obtained a robust vaccine formulation named EV71@NanoAlum, which features significantly enhanced thermostability and immunogenicity. This attempt follows a material-based tactic for vaccine improvement. PMID:27098047

  11. Recent advances in canine leptospirosis: focus on vaccine development

    Directory of Open Access Journals (Sweden)

    Klaasen HLBM

    2015-06-01

    Full Text Available Henricus LBM (Eric Klaasen,1 Ben Adler2 1Global Companion Animals Research and Development, Merck Sharp and Dohme Animal Health, Boxmeer, the Netherlands; 2Department of Microbiology, Monash University, Clayton, VIC, Australia Abstract: Leptospirosis is a global infection of humans and animals caused by pathogenic Leptospira spp. Leptospirosis is a major zoonosis, with infection acquired from wild and domestic animals. It is also a significant cause of morbidity, mortality, and economic loss in production and companion animals. Leptospirosis in dogs is prevalent worldwide and as well as a cause of canine disease, it presents a zoonotic risk to human contacts. Canine leptospirosis does not differ greatly from the syndromes seen in other animal species, with hepatic, renal, and pulmonary involvement being the main manifestations. While the pathogenesis of disease is well documented at the whole animal level, the cellular and molecular basis remains obscure. Killed, whole-cell bacterin vaccines are licensed worldwide and have not changed greatly over the past several decades. Vaccine-induced immunity is restricted to serologically related serovars and is generally short-lived, necessitating annual revaccination. The appearance of new serovars as causes of canine leptospirosis requires constant epidemiological surveillance and tailoring of vaccines to cover emerging serovars. At the present time, there is no realistic prospect of alternative, non-bacterin vaccines in the foreseeable future. Keywords: canine leptospirosis, vaccines, diagnosis, epidemiology, pathogenesis

  12. Status of vaccine research and development for Campylobacter jejuni.

    Science.gov (United States)

    Riddle, Mark S; Guerry, Patricia

    2016-06-01

    Campylobacter jejuni is one of the leading causes of bacterial diarrhea worldwide and is associated with a number of sequelae, including Guillain-Barre Syndrome, reactive arthritis, irritable bowel syndrome and growth stunting/malnutrition. Vaccine development against C. jejuni is complicated by its antigenic diversity, a lack of small animal models, and a poor understanding of the bacterium's pathogenesis. Vaccine approaches have been limited to recombinant proteins, none of which have advanced beyond Phase I testing. Genomic analyses have revealed the presence of a polysaccharide capsule on C. jejuni. Given the success of capsule-conjugate vaccines for other mucosal pathogens of global importance, efforts to evaluate this established approach for C. jejuni are also being pursued. A prototypical capsule-conjugate vaccine has demonstrated efficacy against diarrheal disease in non-human primates and is currently in Phase I testing. In addition to proof of concept studies, more data on the global prevalence of capsular types, and a better understanding of the acute and chronic consequences of C. jejuni are needed to inform investments for a globally relevant vaccine. PMID:26973064

  13. The Immune Space: A Concept and Template for Rationalizing Vaccine Development

    OpenAIRE

    Manrique, Amapola; Adams, Elizabeth; Barouch, Dan H.; Fast, Pat; Graham, Barney S.; Kim, Jerome H.; Kublin, James G.; McCluskey, Margaret; Pantaleo, Giuseppe; Robinson, Harriet L.; Russell, Nina; Snow, William; Johnston, Margaret I.

    2014-01-01

    Empirical testing of candidate vaccines has led to the successful development of a number of lifesaving vaccines. The advent of new tools to manipulate antigens and new methods and vectors for vaccine delivery has led to a veritable explosion of potential vaccine designs. As a result, selection of candidate vaccines suitable for large-scale efficacy testing has become more challenging. This is especially true for diseases such as dengue, HIV, and tuberculosis where there is no validated anima...

  14. Potential use of new poliomyelitis vaccines: memorandum from a WHO meeting.

    OpenAIRE

    1990-01-01

    Largely due to the intensive use of Sabin attenuated oral vaccines, the incidence of poliomyelitis is continuing to decline, particularly in the western hemisphere. In developing and tropical countries, use of trivalent attenuated vaccine may, however, sometimes produce suboptimal antibody responses, especially to type 1 and 3 polioviruses. Epidemics of poliomyelitis continue to occur in some countries with high vaccination coverage, though these are rare, and cases of vaccine-associated para...

  15. Future directions for the development of Chlamydomonas-based vaccines.

    Science.gov (United States)

    Rosales-Mendoza, Sergio

    2013-09-01

    Besides serving as a valuable model in biological sciences, Chamydomonas reinhardtii has been used during the last decade in the biotechnology arena to establish models for the low cost production of vaccines. Antigens from various pathogens including Plasmodium falciparum, foot and mouth disease virus, Staphylococcus aureus, classical swine fever virus (CSFV) as well as some auto-antigens, have been produced in C. reinhardtii. Although some of them have been functionally characterized with promising results, this review identifies future directions for the advancement in the exploitation of this robust and safe vaccine production platform. The present analysis reflects that important immunological implications exist for this system and remain unexplored, including the possible adjuvant effects of algae biomolecules, the effect of bioencapsulation on immunogenicity and the possible development of whole-cell vaccines as an approach to trigger cytotoxic immune responses. Recently described molecular strategies that aim to optimize the expression of nuclear-encoded target antigens are also discussed. PMID:24053395

  16. Cryopreservation and distribution of radiation-attenuated helminth larvae and the use of radioisotopes to monitor their survival. Coordinated programme on preparation of irradiated vaccines against some human diseases

    International Nuclear Information System (INIS)

    Techniques for the cryopreservation of schistosomula are described, from the methanol/two-step cooling technique, through a technique which uses 40% methanol and rapid cooling to the current technique which employs a two-step addition of ethanediol and rapid cooling. Levels of survival with these techniques have improved from 0.3% to 5.9% and now to 47% of control values. The 40% methanol/rapid cooling technique is described in detail as this forms the basis for understanding the role of cryoprotective additives and cooling and warming rates in the cryopreservation of schistosomula. The toxicity of 12 different potentially cryoprotective compounds is described. Cryopreservation of S.japonicum and S.bovis is described. The effect of the age of the schistosomula and their cryopreservability is related to the development of water sensitivity and the permeation and damage produced by glycerol and it is postulated that morphological changes occurring in the tegument during transformation from a cercaria to schistosomulum may account for these observations. Studies with 14C-ethanediol are described which attempt to provide an understanding of permeability of cryoprtectants to schistosomula of different ages and at different temperatures. Vaccination studies with cryopreserved and radiation-attenuated schistosomula are also reported. Radiation-attenuated schistosomula are also reported. Radiation-attenuated cercariae and schistosomula produced high (64% to 89%) levels of protection in baboons, and cryopreserved schistosomula produced comparable levels of protection in vaccinated mice to normal schistosomula. Cryopreserved radiation-attenuated schistosomula produced a significant level of protection (49% reduction) in sheep although the numbers of normally motile organisms injected was low (1,000 per dose, 2 doses). It is concluded that normally-motile cryopreserved radiation-attenuated schistosomula are as immunogenic as fresh organisms

  17. Protection of cattle against rinderpest by vaccination with wild-type but not attenuated strains of peste des petits ruminants virus

    OpenAIRE

    Holzer, Barbara; Hodgson, Sophia; Logan, Nicola; Willett, Brian; Baron, Michael D.

    2016-01-01

    Although rinderpest virus (RPV) has been eradicated in the wild, efforts are still continuing to restrict the extent to which live virus is distributed in facilities around the world and to prepare for any reappearance of the disease, whether through deliberate or accidental release. In an effort to find an alternative vaccine which could be used in place of the traditional live attenuated RPV strains, we have determined whether cattle can be protected from rinderpest by inoculation with vacc...

  18. An attenuated Lassa vaccine in SIV-infected rhesus macaques does not persist or cause arenavirus disease but does elicit Lassa virus-specific immunity

    OpenAIRE

    Zapata, Juan C.; Poonia, Bhawna; Bryant, Joseph; Davis, Harry; Ateh, Eugene; George, Lanea; Crasta, Oswald R.; Yan ZHANG; Slezak, Tom; Jaing, Crystal; Pauza, C D; Goicochea, Marco; Moshkoff, Dmitry; Lukashevich, Igor S.; Salvato, Maria S.

    2013-01-01

    Abstract Background Lassa hemorrhagic fever (LHF) is a rodent-borne viral disease that can be fatal for human beings. In this study, an attenuated Lassa vaccine candidate, ML29, was tested in SIV-infected rhesus macaques for its ability to elicit immune responses without instigating signs pathognomonic for arenavirus disease. ML29 is a reassortant between Lassa and Mopeia viruses that causes a transient infection in non-human primates and confers sterilizing protection from lethal Lassa viral...

  19. A live attenuated H7N7 candidate vaccine virus induces neutralizing antibody that confers protection from challenge in mice, ferrets and monkeys

    Science.gov (United States)

    A live attenuated H7N7 candidate vaccine virus was generated by reverse genetics using the modified hemagglutinin (HA) and neuraminidase (NA) genes of HP A/Netherlands/219/03 (NL/03) (H7N7) wild-type (wt) virus and the six internal protein genes of the cold-adapted (ca) A/Ann Arbor/6/60 ca (AA ca) (...

  20. Transient Loss of Protection Afforded by a Live Attenuated Non-typhoidal Salmonella Vaccine in Mice Co-infected with Malaria

    OpenAIRE

    Mooney, Jason P.; Lee, Seung-Joo; Lokken, Kristen L.; Nanton, Minelva R.; Nuccio, Sean-Paul; Stephen J McSorley; Tsolis, Renée M.

    2015-01-01

    In immunocompetent individuals, non-typhoidal Salmonella serovars (NTS) are associated with gastroenteritis, however, there is currently an epidemic of NTS bloodstream infections in sub-Saharan Africa. Plasmodium falciparum malaria is an important risk factor for invasive NTS bloodstream in African children. Here we investigated whether a live, attenuated Salmonella vaccine could be protective in mice, in the setting of concurrent malaria. Surprisingly, mice acutely infected with the nonletha...

  1. Biotechnology in the diagnosis of infectious diseases and vaccine development

    Science.gov (United States)

    Molecular biological methods have become increasingly applicable to the diagnosis of infectious diseases and vaccine development. To become widely used the methods need to be easy, safe, sensitive, reproducible and eventually automated to facilitate the evaluation of large number of samples. The p...

  2. Economic evaluations of hepatitis B vaccination for developing countries

    NARCIS (Netherlands)

    H.A.T. Tu; H.J. Woerdenbag; S. Kane; A. Riewpaiboon; M. van Hulst; M.J. Postma

    2009-01-01

    Economic evaluations, in particular cost-effectiveness, are important determinants for policy makers and stakeholders involved in decision-making for health interventions. Up until now, most evaluations of cost-effectiveness of hepatitis B vaccination have been performed in developed countries. Appr

  3. New tuberculosis vaccines.

    Science.gov (United States)

    Martín Montañés, Carlos; Gicquel, Brigitte

    2011-03-01

    The current tuberculosis (TB) vaccine, bacille Calmette-Guerin (BCG), is a live vaccine used worldwide, as it protects against severe forms of the disease, saving thousands of lives every year, but its efficacy against pulmonary forms of TB, responsible for transmission of the diseases, is variable. For more than 80 years now no new TB vaccines have been successfully developed. Over the last decade the effort of the scientific community has resulted in the design and construction of promising vaccine candidates. The goal is to develop a new generation of vaccines effective against respiratory forms of the disease. We will focus this review on new prophylactic vaccine candidates that aim to prevent TB diseases. Two are the main strategies used to improve the immunity conferred by the current BCG vaccine, by boosting it with new subunit vaccines, and a second strategy is focused on the construction of new more effective live vaccines, capable to replace the current BCG and to be used as prime vaccines. After rigorous preclinical studies in different animal models new TB vaccine candidates enter in clinical trials in humans. First, a small Phase I for safety followed by immunological evaluation in Phase II trials and finally evaluated in large population Phase III efficacy trials in endemic countries. At present BCG prime and boost with different subunit vaccine candidates are the more advanced assessed in Phase II. Two prime vaccines (based on recombinant BCG) have been successfully evaluated for safety in Phase I trials. A short number of live attenuated vaccines are in advance preclinical studies and the candidates ready to enter Phase I safety trials are produced under current good manufacturing practices. PMID:21420568

  4. Vaccination of pigs with attenuated Lawsonia intracellularis induced acute phase protein responses and primed cell-mediated immunity without reduction in bacterial shedding after challenge

    DEFF Research Database (Denmark)

    Riber, Ulla; Heegaard, Peter M. H.; Hvass, Henriette Cordes; Ståhl, Marie; Jensen, Tim Kåre; Jungersen, Gregers

    2015-01-01

    same extent as non-vaccinated pigs after challenge,however less L. intracellularis in ileum and lymph nodes was seen post mortem. In the RE group, challengedid not lead to L. intracellularis shedding and no challenge bacteria were found post mortem. In both VACand RE the acute phase haptoglobin...... response was diminished and L. intracellularis specific IgG responseswere delayed and reduced compared to non-vaccinated pigs. On the other hand L. intracellularis specificIFN- responses tended to develop faster in the VAC group compared to controls.Conclusion: Although vaccinated and non-vaccinated pigs...

  5. Development of Toxoplasma gondii vaccine: A global challenge.

    Science.gov (United States)

    Verma, Ramesh; Khanna, Pardeep

    2013-02-01

    Toxoplasmosis is caused by the protozoan parasite T. gondii. Humans and other warm-blooded animals are its hosts. The infection has a worldwide distribution; one-third of the world's population has been exposed to this parasite. There are three primary ways of transmission: ingesting uncooked meat containing tissue cysts, ingesting food and water contaminated with oocysts from infected cat feces and congenitally. Those particularly at risk of developing clinical illness include pregnant women, given that the parasite can pose a serious threat to the unborn child if the mother becomes infected while pregnant, and immunosuppressed individuals such as tissue transplant subjects, AIDS subjects, those with certain types of cancer and those undergoing certain forms of cancer therapy. Maternal infections early in pregnancy are less likely to be transmitted to the fetus than infections later in pregnancy, but early fetal infections are more likely to be severe than later infections. In the absence of an effective human vaccine, prevention of zoonotic transmission might be the best way to approach the problem of toxoplasmosis and must be done by limiting exposure to oocysts or tissue cysts. Vaccine development to prevent feline oocyst shedding is ongoing, mostly with live vaccines. The S48 strain Toxovax is a live vaccine originally developed for use in sheep, but when used in cats inhibits sexual development of T. gondii. This vaccine is used in sheep to reduce tissue cyst development. The T-263 strain of T. gondii is a live mutant strain designed to reduce or prevent oocyst shedding by cats by developing only partial infection in the feline intestinal tract. PMID:23111123

  6. Effect Evaluation on Emergency Vaccination of Rubella Attenuated Live Vaccine for Controlling the Outbreak of Rubella%风疹减毒活疫苗应急接种对控制风疹疫情效果评价

    Institute of Scientific and Technical Information of China (English)

    王兆芳; 王勇; 王平

    2011-01-01

    Objective To summarize the effect of rubella emergency vaccination compaign-in Tongling Municipal in 2009 and to know rubella epidemiological characteristics in Tongling city, and to provide evidence strategies and measures for rubella preventions and control. Methods The effect of rubella emergency vaccination compaign and epidemiologic characteristics of Rubella were analyzed comprehensively, including the system surveillance information of measles, coverage rate of rubella emergency vaccination compaign, the rubella antibody. Result The outbreak of rubella happened in Tongling in 2009. After that, they conducted the emergency vaccination, and total reported coverage of Rubella vaccine was88.30%, total coverage of survey was 91.67%, the positive rate of rubella IgG antibody was 97.14% after emergency vaccination campaign, the morbidity of Rubella decreased obviously. Conclusion Rubella cases 6-18 years old decreased remarkably after emergency vaccination campaign. The key successful activities were conducting the emergency vaccination of Rubella Attenuated Live Vaccine for the population aged 6'-18 years and to establish effective immunity barrier to interrupt the virus transmission within the shortest time.%目的 评价铜陵市2009年实施风疹减毒活疫苗(Rubella Attenuated Live Vaccine,RV)应急接种免疫效果,分析风疹的流行病学特征,为控制风疹提供依据.方法 利用麻疹监测系统资料、RV应急接种资料、人群风疹抗体监测资料,综合分析RV应急接种的效果及风疹的流行病学特征.结果 铜陵市2009年发生风疹疫情,RV应急接种报告接种率为88.30%,调查接种率为91.67%,应急接种后人群风疹IgG抗体阳性率为97.14%,发病率显著下降.结论 对6~18岁目标人群进行RV应急接种,能迅速形成有效的免疫屏障,阻断风疹病毒传播,控制风疹流行.

  7. Recoding of the Vesicular Stomatitis Virus L Gene by Computer-Aided Design Provides a Live, Attenuated Vaccine Candidate

    OpenAIRE

    Wang, Bingyin; Yang, Chen; Tekes, Gergely; Mueller, Steffen; Paul, Aniko; Whelan, Sean P. J.; Wimmer, Eckard

    2015-01-01

    ABSTRACT Codon pair bias (CPB), which has been observed in all organisms, is a neglected genomic phenomenon that affects gene expression. CPB results from synonymous codons that are paired more or less frequently in ORFeomes regardless of codon bias. The effect of an individual codon pair change is usually small, but when it is amplified by large-scale genome recoding, strikingly altered biological phenotypes are observed. The utility of codon pair bias in the development of live attenuated v...

  8. Pathology associated with vaccination against Schistosoma mansoni in mice using cryopreserved radiation attenuated schistosomula

    International Nuclear Information System (INIS)

    Twenty-one mice were injected intramuscularly with 2000 Schistosoma mansoni schistosomula irradiated at 20 krad and cryopreserved; three mice were killed on each of day 0, 2, 5, 9, 19, 28 and 44 days after infection and muscle from the site of injection in the left hind leg, the lungs and livers removed for histological examination. Schistosomula were seen in sections from the leg muscle from days 0 to 19 inclusive, in the lungs from day 2 to day 28 inclusive and in the livers from days 9 to 28 inclusive. Most schistosomula were seen in sections of the leg muscle with considerably fewer parasites occurring in the lungs and especially the livers. Granulomatous reactions comprising eosinophils, polymorphs, plasma cells and macrophages were first seen in the leg muscle on day 2, in the lungs on day 5 and in the liver on day 19. The peak inflammatory reactions appeared to occur between days 5 and 9, 9 and 19 and 28 and 44 respectively in the three tissues. The pathology is discussed in relation to the dose of irradiation required to attenuate the schistosomula for optimal immunogenicity. (author)

  9. Conventional housing conditions attenuate the development of experimental autoimmune encephalomyelitis.

    Directory of Open Access Journals (Sweden)

    Andreas Arndt

    Full Text Available BACKGROUND: The etiology of multiple sclerosis (MS has remained unclear, but a causative contribution of factors outside the central nervous system (CNS is conceivable. It was recently suggested that gut bacteria trigger the activation of CNS-reactive T cells and the development of demyelinative disease. METHODS: C57BL/6 (B6 mice were kept either under specific pathogen free or conventional housing conditions, immunized with the myelin basic protein (MBP-proteolipid protein (PLP fusion protein MP4 and the development of EAE was clinically monitored. The germinal center size of the Peyer's patches was determined by immunohistochemistry in addition to the level of total IgG secretion which was assessed by ELISPOT. ELISPOT assays were also used to measure MP4-specific T cell and B cell responses in the Peyer's patches and the spleen. Ear swelling assays were performed to determine the extent of delayed-type hypersensitivity reactions in specific pathogen free and conventionally housed mice. RESULTS: In B6 mice that were actively immunized with MP4 and kept under conventional housing conditions clinical disease was significantly attenuated compared to specific pathogen free mice. Conventionally housed mice displayed increased levels of IgG secretion in the Peyer's patches, while the germinal center formation in the gut and the MP4-specific TH17 response in the spleen were diminished after immunization. Accordingly, these mice displayed an attenuated delayed type hypersensitivity (DTH reaction in ear swelling assays. CONCLUSIONS: The data corroborate the notion that housing conditions play a substantial role in the induction of murine EAE and suggest that the presence of gut bacteria might be associated with a decreased immune response to antigens of lower affinity. This concept could be of importance for MS and calls for caution when considering the therapeutic approach to treat patients with antibiotics.

  10. Evolution of animal models in cancer vaccine development.

    Science.gov (United States)

    Wei, Wei-Zen; Jones, Richard F; Juhasz, Csaba; Gibson, Heather; Veenstra, Jesse

    2015-12-16

    Advances in cancer vaccine development are facilitated by animal models reflecting key features of human cancer and its interface with host immunity. Several series of transplantable preneoplastic and neoplastic mouse mammary lesions have been used to delineate mechanisms of anti-tumor immunity. Mimicking immune tolerance to tumor-associated antigens (TAA) such as HER2/neu, transgenic mice developing spontaneous mammary tumors are strong model systems for pre-clinical vaccine testing. In these models, HER2 DNA vaccines are easily administered, well-tolerated, and induce both humoral and cellular immunity. Although engineered mouse strains have advanced cancer immunotherapy, basic shortcomings remain. For example, multiple mouse strains have to be tested to recapitulate genetic regulation of immune tolerance in humans. Outbred domestic felines more closely parallel humans in the natural development of HER2 positive breast cancer and their varying genetic background. Electrovaccination with heterologous HER2 DNA induces robust adaptive immune responses in cats. Importantly, homologous feline HER2 DNA with a single amino acid substitution elicits unique antibodies to feline mammary tumor cells, unlocking a new vaccine principle. As an alternative approach to targeted vaccination, non-surgical tumor ablation such as cryoablation induces anti-tumor immunity via in situ immunization, particularly when combined with toll-like receptor (TLR) agonist. As strategies for vaccination advance, non-invasive monitoring of host response becomes imperative. As an example, magnetic resonance imaging (MRI) and positron emission tomography (PET) scanning following administration of tryptophan metabolism tracer [11C]-alpha-methyl-tryptophan (AMT) provides non-invasive imaging of both tumor growth and metabolic activities. Because AMT is a substrate of indoleamine-pyrrole 2,3-dioxygenase (IDO), an enzyme that produces the immune regulatory molecule kynurenine, AMT imaging can provide

  11. Quality vaccines for all people: Report on the 16th annual general meeting of the Developing Countries Vaccine Manufacturers' Network, 05-07th October 2015, Bangkok, Thailand.

    Science.gov (United States)

    Pagliusi, Sonia; Ting, Ching-Chia; Khomvilai, Sumana

    2016-06-30

    The Developing Countries Vaccine Manufacturers Network (DCVMN) assembled high-profile leaders from global health organisations and vaccine manufactures for its 16th Annual General Meeting to work towards a common goal: providing quality vaccines for all people. Vaccines contribute to a healthy community and robust health system; the Ebola outbreak has raised awareness of the threat and damage one single infectious disease can make, and it is clear that the world was not prepared. However, more research to better understand emerging infectious agents might lead to suitable vaccines which help prevent future outbreaks. DCVMN members presented their progress in developing novel vaccines against Dengue, HPV, Chikungunya, Cholera, cell-based influenza and other vaccines, demonstrating the commitment towards eliminating and eradicating preventable diseases worldwide through global collaboration and technology transfer. The successful introduction of novel Sabin-IPV and Oral Cholera vaccine in China and Korea respectively in 2015 was highlighted. In order to achieve global immunisation, local authorities and community leaders play an important role in the decision-making in vaccine introduction and uptake, based on the ability of vaccines to protect vaccinated people and protect non-vaccinated in the community through herd immunity. Reducing the risk of vaccine shortages can also be achieved by increasing regulatory convergence at regional and international levels. Combatting preventable diseases remains challenging, and collective efforts for improving multi-centre clinical trials, creating regional vaccine security strategies, fostering developing vaccine markets and procurement, and building trust in vaccines were discussed. PMID:26947496

  12. Biological challenges to effective vaccines in the developing world.

    Science.gov (United States)

    Grassly, Nicholas C; Kang, Gagandeep; Kampmann, Beate

    2015-06-19

    The reason for holding a meeting to discuss biological challenges to vaccines is simple: not all vaccines work equally well in all settings. This special issue reviews the performance of vaccines in challenging environments, summarizes current thinking on the reasons why vaccines underperform and considers what approaches are necessary to understand the heterogeneity in responses and to improve vaccine immunogenicity and efficacy. PMID:25964451

  13. Biological challenges to effective vaccines in the developing world

    OpenAIRE

    Grassly, Nicholas C.; Kang, Gagandeep; Kampmann, Beate

    2015-01-01

    The reason for holding a meeting to discuss biological challenges to vaccines is simple: not all vaccines work equally well in all settings. This special issue reviews the performance of vaccines in challenging environments, summarizes current thinking on the reasons why vaccines underperform and considers what approaches are necessary to understand the heterogeneity in responses and to improve vaccine immunogenicity and efficacy.

  14. TB vaccine development: where are we and why is it so difficult?

    OpenAIRE

    Wilkie, Morven E M; McShane, Helen

    2014-01-01

    The development of an effective TB vaccine remains paramount to achieving the goal of global eradication of TB by 2050. The only licensed vaccine, BCG, has variable efficacy and is poorly effective in high burden countries. The development of promising candidate vaccines to either ‘boost’ a BCG primed immune system or replace BCG altogether is a key area for innovative research. Here, we discuss some of the issues encountered in the development of potential candidate vaccines and the future c...

  15. A contribution to the development of anti-tick vaccines

    OpenAIRE

    Nijhof, A. M.

    2010-01-01

    Ticks and tick-borne diseases seriously affect animal and human health worldwide with the highest economic losses occurring in livestock production in the developing world. The control of ticks and the diseases they transmit depends mainly on chemical tick control using acaricides. The development of acaricide resistance, concerns about environmental pollution and pesticide residues in food products result in the need for alternative tick control methods such as anti-tick vaccines. Commercial...

  16. Immunity to schistosomiasis mansoni in guinea-pigs vaccinated with radiation-attenuated cercariae. Humoral responses against skin-stage schistosomula

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, J.R.; McLaren, D.J.

    1987-02-01

    The anti-schistosomular humoral responses of guinea-pigs vaccinated with radiation-attenuated cercariae of Schistosoma mansoni have been investigated in vitro. The sera of vaccinated animals contain schistosomulicidal complement-fixing antibodies which peak in titre at week 5 after vaccination and predominantly consist of IgG/sub 2/ and IgM antibodies. The ability of the serum to arm macrophages from normal animals to bind to schistosomula, also peaks in titre at week 5 and is associated with IgG/sub 2/ antibodies. Basophils from normal animals can be sensitized in vitro by vaccine serum to degranulate in the presence of schistosomular antigens. This anaphylactic antibody activity is associated with IgG/sub 1/ but not IgE antibodies, and peaks in titre at week 10. Three antigens (14 kD, 20 kD and 43 kD) are specifically and transiently detected by vaccine serum on Western blots of schistosomular proteins; these antigens are first discernible at week 4, but were virtually undetectable at week 12.

  17. Universal varicella vaccine immunization in Japan.

    Science.gov (United States)

    Yoshikawa, Tetsushi; Kawamura, Yoshiki; Ohashi, Masahiro

    2016-04-01

    In 1974, Japanese scientists developed a live attenuated varicella vaccine based on the Oka strain. The efficacy of the vaccine for the prevention of varicella has been primarily demonstrated in studies conducted in the United States following the adoption of universal immunization using the Oka strain varicella vaccine in 1996. Although the vaccine was developed by Japanese scientists, until recently, the vaccine has been administered on a voluntary basis in Japan resulting in a vaccine coverage rate of approximately 40%. Therefore, Japan initiated universal immunization using the Oka strain varicella vaccine in November 2014. Given the transition from voluntary to universal immunization in Japan, it will also be important to monitor the epidemiology of varicella and herpes zoster. The efficacy and safety of co-administration of the varicella vaccine and measles, mumps, and rubella vaccine have been demonstrated in many countries; however, there was no data from Japan. In order to adopt the practice of universal immunization using the Oka strain varicella vaccine in Japan, data demonstrating the efficacy and safety of co-administration of varicella vaccine and measles and rubella (MR) vaccine were required. Additionally, we needed to elucidate the appropriate time interval between the first and second administrations of the vaccine. It is also important to differentiate between wild type and Oka vaccine type strains in herpes zoster patient with past history of varicella vaccine. Thus, there are many factors to consider regarding the adoption of universal immunization in Japan to control varicella zoster virus (VZV) infections. PMID:26944711

  18. Human Vaccines & Immunotherapeutics

    OpenAIRE

    Riedmann, Eva M.

    2013-01-01

    DNA vaccine for T1D promising in the clinic HPV vaccines halved infections in US teenage girls Modified DC immunotherapy against melanoma New study looks at clinical severity of human H7N9 infections Prevnar vaccines are valuable for healthcare systems GAPVAC: New consortium in the fight of brain cancer Cytomegalovirus vaccine to enter phase 3 Malaria vaccination using chemically attenuated parasites

  19. Development of an Aeromonas hydrophila recombinant extracellular protease vaccine.

    Science.gov (United States)

    Wu, Lei; Jiang, Ya-nan; Tang, Qian; Lin, Hui-xing; Lu, Cheng-ping; Yao, Huo-chun

    2012-01-01

    Aeromonas hydrophila (Ah) exists widely in the aquatic environment and infects a variety of animals. Extracellular protease (EPR) is an important protective antigen that induces a specific antibody response to resist Ah infection. In this study, two genes encoding extracellular protease epr2 and epr3 were linked within the expression vector pET32a to construct a recombinant pET-epr2-3 plasmid. The immunogenicity of the fusion protein epr2-3 was investigated as a subunit vaccine in ICR mice. The recombinant epr2-3 protein induced the production of high antibody titers. The survival rate against homogenous Ah J-1 challenge was significantly higher in the epr2-3 vaccinated group (≥80%) compared with the inactivated Ah vaccinated group and the challenge control group (P < 0.01), thus indicating that the recombinant epr2-3 protein provided significant protection against Ah infection. Therefore, the recombinant epr2-3 is a promising candidate for development as a vaccine against Ah infections. PMID:22874879

  20. Animal Models for Influenza Viruses: Implications for Universal Vaccine Development

    Directory of Open Access Journals (Sweden)

    Irina Margine

    2014-10-01

    Full Text Available Influenza virus infections are a significant cause of morbidity and mortality in the human population. Depending on the virulence of the influenza virus strain, as well as the immunological status of the infected individual, the severity of the respiratory disease may range from sub-clinical or mild symptoms to severe pneumonia that can sometimes lead to death. Vaccines remain the primary public health measure in reducing the influenza burden. Though the first influenza vaccine preparation was licensed more than 60 years ago, current research efforts seek to develop novel vaccination strategies with improved immunogenicity, effectiveness, and breadth of protection. Animal models of influenza have been essential in facilitating studies aimed at understanding viral factors that affect pathogenesis and contribute to disease or transmission. Among others, mice, ferrets, pigs, and nonhuman primates have been used to study influenza virus infection in vivo, as well as to do pre-clinical testing of novel vaccine approaches. Here we discuss and compare the unique advantages and limitations of each model.

  1. Health Impact of Rotavirus Vaccination in Developing Countries: Progress and Way Forward.

    Science.gov (United States)

    Parashar, Umesh D; Johnson, Hope; Steele, A Duncan; Tate, Jacqueline E

    2016-05-01

    Two rotavirus vaccines have been licensed in >100 countries worldwide since 2006. As of October 2105, these vaccines have been implemented in the national immunization programs of 79 countries, including 36 low-income countries that are eligible for support for vaccine purchase from Gavi, the Vaccine Alliance. Rotavirus vaccines were initially introduced in Australia and countries of the Americas and Europe after completion of successful clinical trials in these regions, and the impact of routine vaccination in reducing the health burden of severe childhood gastroenteritis in these regions has been well documented. Because of concerns around the performance of orally administered rotavirus vaccines in developing countries, vaccine implementation in these settings only began after additional clinical trials were completed and the World Health Organization issued a global recommendation for use of rotavirus vaccines in 2009. This supplementary issue ofClinical Infectious Diseasesincludes a collection of articles describing the impact and effectiveness of routine rotavirus vaccination in developing countries that were among the early adopters of rotavirus vaccine. The data highlight the benefits of vaccination and should provide valuable evidence to sustain vaccine use in these countries and encourage other countries to adopt routine rotavirus vaccination to reduce the health burden of severe childhood gastroenteritis. PMID:27059361

  2. Cost-effectiveness analysis of the direct and indirect impact of intranasal live attenuated influenza vaccination strategies in children: alternative country profiles

    Science.gov (United States)

    Gibson, Edward; Begum, Najida; Martinón-Torres, Federico; Safadi, Marco Aurélio; Sackeyfio, Alfred; Hackett, Judith; Rajaram, Sankarasubramanian

    2016-01-01

    Background Influenza poses a significant burden on healthcare systems and society, with under-recognition in the paediatric population. Existing vaccination policies (largely) target the elderly and other risk groups where complications may arise. Objective The goal of this study was to evaluate the cost-effectiveness of annual paediatric vaccination (in 2–17-year-olds) with live attenuated influenza vaccination (LAIV), as well as the protective effect on the wider population in England and Wales (base). The study aimed to demonstrate broad applications of the model in countries where epidemiological and transmission data is limited and that have sophisticated vaccination policies (Brazil, Spain, and Taiwan). Methods The direct and indirect impact of LAIV in the paediatric cohort was simulated using an age-stratified dynamic transmission model over a 5-year time horizon of daily cycles and applying discounting of 3.5% in the base case. Pre-existing immunity structure was based on a 1-year model run. Sensitivity analyses were conducted. Results In the base case for England and Wales, the annual paediatric strategy with LAIV was associated with improvements in influenza-related events and quality-adjusted life years (QALYs) lost, yielding an incremental cost per QALY of £6,208. The model was robust to change in the key input parameters. The probabilistic analysis demonstrated LAIV to be cost effective in more than 99% of iterations, assuming a willingness-to-pay threshold of £30,000. Incremental costs per QALY for Brazil were £2,817, and for the cases of Spain and Taiwan the proposed strategy was dominant over the current practice. Conclusion In addition to existing policies, annual paediatric vaccination using LAIV provides a cost-effective strategy that offers direct and indirect protection in the wider community. Paediatric vaccination strategies using LAIV demonstrated clinical and economic benefits over alternative (current vaccination) strategies in

  3. Newcastle Disease Virus-Based Live Attenuated Vaccine Completely Protects Chickens and Mice from Lethal Challenge of Homologous and Heterologous H5N1 Avian Influenza Viruses▿

    Science.gov (United States)

    Ge, Jinying; Deng, Guohua; Wen, Zhiyuan; Tian, Guobing; Wang, Yong; Shi, Jianzhong; Wang, Xijun; Li, Yanbing; Hu, Sen; Jiang, Yongping; Yang, Chinglai; Yu, Kangzhen; Bu, Zhigao; Chen, Hualan

    2007-01-01

    H5N1 highly pathogenic avian influenza virus (HPAIV) has continued to spread and poses a significant threat to both animal and human health. Current influenza vaccine strategies have limitations that prevent their effective use for widespread inoculation of animals in the field. Vaccine strains of Newcastle disease virus (NDV), however, have been used successfully to easily vaccinate large numbers of animals. In this study, we used reverse genetics to construct a NDV that expressed an H5 subtype avian influenza virus (AIV) hemagglutinin (HA). Both a wild-type and a mutated HA open reading frame (ORF) from the HPAIV wild bird isolate, A/Bar-headed goose/Qinghai/3/2005 (H5N1), were inserted into the intergenic region between the P and M genes of the LaSota NDV vaccine strain. The recombinant viruses stably expressing the wild-type and mutant HA genes were found to be innocuous after intracerebral inoculation of 1-day-old chickens. A single dose of the recombinant viruses in chickens induced both NDV- and AIV H5-specific antibodies and completely protected chickens from challenge with a lethal dose of both velogenic NDV and homologous and heterologous H5N1 HPAIV. In addition, BALB/c mice immunized with the recombinant NDV-based vaccine produced H5 AIV-specific antibodies and were completely protected from homologous and heterologous lethal virus challenge. Our results indicate that recombinant NDV is suitable as a bivalent live attenuated vaccine against both NDV and AIV infection in poultry. The recombinant NDV vaccine may also have potential use in high-risk human individuals to control the pandemic spread of lethal avian influenza. PMID:17050610

  4. Enhancement by ampicillin of antibody responses induced by a protein antigen and a DNA vaccine carried by live-attenuated Salmonella enterica serovar Typhi.

    Science.gov (United States)

    Woo, P C; Tsoi, H W; Leung, H C; Wong, L P; Wong, S S; Chan, E; Yuen, K Y

    2000-07-01

    Live-attenuated Salmonella species are effective carriers of microbial antigens and DNA vaccines. In a mouse model, the immunoglobulin M (IgM) and total antibody levels directed toward the lipopolysaccharide of Salmonella enterica serovar Typhi were significantly enhanced at day 21 after oral immunization with live-attenuated serovar Typhi (strain Ty21a) when ampicillin was concomitantly administered (P Ty21a-stimulated lymphocyte proliferation indices for the ampicillin group at day 21 were significantly higher than those for the normal saline (NS) group (P Ty21a per well, respectively). The 50% lethal doses for mice from the ampicillin and NS groups immunized with Ty21a with pBR322 after wild-type serovar Typhi challenge on day 24 were 3.4 x 10(7) and 5.0 x 10(6) CFU, respectively. The fecal bacterial counts for the ampicillin group at days 1, 3, and 5 were significantly lower than those for the NS group (P Ty21a in a larger number of mice from the ampicillin group than from the NS group. Furthermore, the IgG2a levels directed toward tetanus toxoid were significantly enhanced at days 7 and 21 after oral immunization with Ty21a that carried the fragment c of tetanus toxoid when ampicillin was concomitantly administered (P Ty21a that carried the DNA vaccine that encodes hepatitis B surface antigen when ampicillin was concomitantly administered. The present observation may improve the efficacy of the protein antigens and DNA vaccines carried in live-attenuated bacteria, and further experiments should be carried out to determine the best antibiotics and dosage regimen to be used, as well as the best carrier system for individual protein antigens and DNA vaccines. PMID:10882658

  5. Protein conjugate polysaccharide vaccines: Challenges in development and global implementation

    Directory of Open Access Journals (Sweden)

    Manisha Nair

    2012-01-01

    Replacement by nonvaccine serotypes;capsule switching;time duration of the antibody protective effect following vaccination;costs of the vaccines, programme costs, lack of knowledge of the disease burden, and targeting population groups for vaccination.

  6. An Epidemiological Study on Measles Cases with Vaccination History of Measles Attenuated Live Vaccine%有麻疹减毒活疫苗接种史的麻疹病例流行病学分析

    Institute of Scientific and Technical Information of China (English)

    赵艳荣; 陈恩富; 李倩; 蒋征刚; 何寒青; 凌罗亚

    2011-01-01

    Objective To know the distribution characteristics of measles cases with vaccination history of measles attenuated live vaccine (MV ) and to provide base data for Measles control and prevention. Methods A descriptive epidemiological study was conducted to analyze measles cases with or without vaccination history of measles attenuated vaccine reported in Zhejiang province in 2009. Results The confirmed measles cases with vaccination history of measles vaccine was obviously lower than (16.44% ) non-measles cases (41.45%). The shortest interval between the latest MV vaccination and onset of measles case was Od, the longest is 25 years, with a median of 3 months. The occurrence of Measles of interval proportions <1 month, 1-11 months, 1-9 years, 10-25 years were 42.10%, 30.19%, 19.50%, 6.92% respectively. The interval distribution was different by age groups. Some symptoms were milder in the cases with MV history than that without MV history. For cases with different interval between recent MV vaccination and onset of measles, conjunctivitis was less in those of 6-10d than others. Conclusion Measles cases with MV history could be resulted from primary or secondary immunization failure, or time vaccinated at the late incubation period. Few cases may actually be vaccine reactions at 6-10d after vaccination.%目的 了解有麻疹减毒活疫苗(Measles Attenuated Live Vaccine,MV)接种史的麻疹病例的分布特点,为查找原因及提出控制措施提供基础数据.方法 对浙江省2009年报告的有、无MV接种史的麻疹病例进行描述流行病学分析.结果 麻疹确诊病例中,有MV接种史的比例(16.44%)明显低于非麻疹病例(41.45%).末次接种距发病最短间隔为0d,最长为25年,中位数为3个月.接种后<1个月、1~11个月、1~9年、10~25年的发病构成分别为42.10%、30.19%、19.50%、6.92%,不同年龄组末次接种距发病时间分布不同.有MV接种史的麻疹病例与无接种史者相比

  7. A live-attenuated HSV-2 ICP0 virus elicits 10 to 100 times greater protection against genital herpes than a glycoprotein D subunit vaccine.

    Directory of Open Access Journals (Sweden)

    William P Halford

    Full Text Available Glycoprotein D (gD-2 is the entry receptor of herpes simplex virus 2 (HSV-2, and is the immunogen in the pharmaceutical industry's lead HSV-2 vaccine candidate. Efforts to prevent genital herpes using gD-2 subunit vaccines have been ongoing for 20 years at a cost in excess of $100 million. To date, gD-2 vaccines have yielded equivocal protection in clinical trials. Therefore, using a small animal model, we sought to determine if a live-attenuated HSV-2 ICP0⁻ virus would elicit better protection against genital herpes than a gD-2 subunit vaccine. Mice immunized with gD-2 and a potent adjuvant (alum+monophosphoryl lipid A produced high titers of gD-2 antibody. While gD-2-immunized mice possessed significant resistance to HSV-2, only 3 of 45 gD-2-immunized mice survived an overwhelming challenge of the vagina or eyes with wild-type HSV-2 (MS strain. In contrast, 114 of 115 mice immunized with a live HSV-2 ICP0⁻ virus, 0ΔNLS, survived the same HSV-2 MS challenges. Likewise, 0ΔNLS-immunized mice shed an average 125-fold less HSV-2 MS challenge virus per vagina relative to gD-2-immunized mice. In vivo imaging demonstrated that a luciferase-expressing HSV-2 challenge virus failed to establish a detectable infection in 0ΔNLS-immunized mice, whereas the same virus readily infected naïve and gD-2-immunized mice. Collectively, these results suggest that a HSV-2 vaccine might be more likely to prevent genital herpes if it contained a live-attenuated HSV-2 virus rather than a single HSV-2 protein.

  8. Safety and immunogenicity of a mutagenized, live attenuated Rift Valley fever vaccine, MP-12, in a Phase 1 dose escalation and route comparison study in humans.

    Science.gov (United States)

    Pittman, Phillip R; McClain, David; Quinn, Xiaofei; Coonan, Kevin M; Mangiafico, Joseph; Makuch, Richard S; Morrill, John; Peters, Clarence J

    2016-01-20

    Rift Valley fever (RVF) poses a risk as a potential agent in bioterrorism or agroterrorism. A live attenuated RVF vaccine (RVF MP-12) has been shown to be safe and protective in animals and showed promise in two initial clinical trials. In the present study, healthy adult human volunteers (N=56) received a single injection of (a) RVF MP-12, administered subcutaneously (SQ) at a concentration of 10(4.7) plaque-forming units (pfu) (SQ Group); (b) RVF MP-12, administered intramuscularly (IM) at 10(3.4)pfu (IM Group 1); (c) RVF MP-12, administered IM at 10(4.4)pfu (IM Group 2); or (d) saline (Placebo Group). The vaccine was well tolerated by volunteers in all dose and route groups. Infrequent and minor adverse events were seen among recipients of both placebo and RVF MP-12. One subject had viremia detectable by direct plaque assay, and six subjects from IM Group 2 had transient low-titer viremia detectable only by nucleic acid amplification. Of the 43 vaccine recipients, 40 (93%) achieved neutralizing antibodies (measured as an 80% plaque reduction neutralization titer [PRNT80]) as well as RVF-specific IgM and IgG. The highest peak geometric mean PRNT80 titers were observed in IM Group 2. Of 34 RVF MP-12 recipients available for testing 1 year following inoculation, 28 (82%) remained seropositive (PRNT80≥1:20); this included 20 of 23 vaccinees (87%) from IM Group 2. The live attenuated RVF MP-12 vaccine was safe and immunogenic at the doses and routes studied. Given the need for an effective vaccine against RVF virus, further evaluation in humans is warranted. PMID:26718688

  9. Human-animal chimeras for vaccine development: an endangered species or opportunity for the developing world?

    OpenAIRE

    Daar Abdallah S; Singer Peter A; Bhan Anant

    2010-01-01

    Abstract Background In recent years, the field of vaccines for diseases such as Human Immunodeficiency Virus (HIV) which take a heavy toll in developing countries has faced major failures. This has led to a call for more basic science research, and development as well as evaluation of new vaccine candidates. Human-animal chimeras, developed with a 'humanized' immune system could be useful to study infectious diseases, including many neglected diseases. These would also serve as an important t...

  10. Business models and opportunities for cancer vaccine developers.

    Science.gov (United States)

    Kudrin, Alex

    2012-10-01

    Despite of growing oncology pipeline, cancer vaccines contribute only to a minor share of total oncology-attributed revenues. This is mainly because of a limited number of approved products and limited sales from products approved under compassionate or via early access entry in smaller and less developed markets. However revenue contribution from these products is extremely limited and it remains to be established whether developers are breaking even or achieving profitability with existing sales. Cancer vaccine field is well recognized for high development costs and risks, low historical rates of investment return and high probability of failures arising in ventures, partnerships and alliances. The cost of reimbursement for new oncology agents is not universally acceptable to payers limiting the potential for a global expansion, market access and reducing probability of commercial success. In addition, the innovation in cancer immunotherapy is currently focused in small and mid-size biotech companies and academic institutions struggling for investment. Existing R&D innovation models are deemed unsustainable in current "value-for-money" oriented healthcare environment. New business models should be much more open to collaborative, networked and federated styles, which could help to outreach global, markets and increase cost-efficiencies across an entire value chain. Lessons learned from some developing countries and especially from South Korea illustrate that further growth of cancer vaccine industry will depends not only on new business models but also will heavily rely on regional support and initiatives from different bodies, such as governments, payers and regulatory bodies. PMID:22894953

  11. Progress of vaccine and drug development for Ebola preparedness.

    Science.gov (United States)

    Choi, Woo Young; Hong, Kee-Jong; Hong, Joo Eun; Lee, Won-Ja

    2015-01-01

    Since the first case of Ebola virus disease (EVD) in Guinea was reported in March 2014 by World Health Organization (WHO), the outbreak has continued through the year and the total number of 19,065 patients was reported as the confirmed or suspected in the EVD-affected countries. Among the cases, 7,388 patients were reported death by 19 December. Currently, available therapeutics to treat the infected patients or vaccines to prevent people from infection is not developed yet while viral diagnostic methods were already developed and firmly established in a lot of countries as a first step for the preparedness of Ebola outbreak. Some potential therapeutic materials including ZMapp were supplied and the treated people got over the EVD. Several candidates of vaccines also were investigated their efficacy in animal models by National Institute of Health (NIH) and Department of Defense, and they are processing of clinical tests in West Africa aiming to finish the development by the 2015. Vaccine and therapeutic development is essential to stop the EVD outbreak in West Africa, also to protect the world from the risk which can be generated by potential spread of Ebola virus. PMID:25648233

  12. Ebola Hemorrhagic Fever and the Current State of Vaccine Development

    OpenAIRE

    Hong, Joo Eun; Hong, Kee-Jong; Choi, Woo Young; Lee, Won-Ja; Choi, Yeon Hwa; Jeong, Chung-Hyeon; Cho, Kwang-il

    2014-01-01

    Current Ebola virus outbreak in West Africa already reached the total number of 1,323 including 729 deaths by July 31st. the fatality is around 55% in the southeastern area of Guinea, Sierra Leone, Liberia, and Nigeria. The number of patients with Ebola Hemorrhagic Fever (EHF) was continuously increasing even though the any effective therapeutics or vaccines has not been developed yet. The Ebola virus in Guinea showed 98% homology with Zaire Ebola Virus. Study of the pathogenesis of Ebola vir...

  13. Transmission blocking malaria vaccines: Assays and candidates in clinical development.

    Science.gov (United States)

    Sauerwein, R W; Bousema, T

    2015-12-22

    Stimulated by recent advances in malaria control and increased funding, the elimination of malaria is now considered to be an attainable goal for an increasing number of malaria-endemic regions. This has boosted the interest in transmission-reducing interventions including vaccines that target sexual, sporogenic, and/or mosquito-stage antigens to interrupt malaria transmission (SSM-VIMT). SSM-VIMT aim to prevent human malaria infection in vaccinated communities by inhibiting parasite development within the mosquito after a blood meal taken from a gametocyte carrier. Only a handful of target antigens are in clinical development and progress has been slow over the years. Major stumbling blocks include (i) the expression of appropriately folded target proteins and their downstream purification, (ii) insufficient induction of sustained functional blocking antibody titers by candidate vaccines in humans, and (iii) validation of a number of (bio)-assays as correlate for blocking activity in the field. Here we discuss clinical manufacturing and testing of current SSM-VIMT candidates and the latest bio-assay development for clinical evaluation. New testing strategies are discussed that may accelerate the evaluation and application of SSM-VIMT. PMID:26409813

  14. The Current Status of the Disease Caused by Enterovirus 71 Infections: Epidemiology, Pathogenesis, Molecular Epidemiology, and Vaccine Development.

    Science.gov (United States)

    Chang, Ping-Chin; Chen, Shou-Chien; Chen, Kow-Tong

    2016-01-01

    Enterovirus 71 (EV71) infections have a major public health impact in the Asia-Pacific region. We reviewed the epidemiology, pathogenesis, and molecular epidemiology of EV71 infection as well as EV71 vaccine development. Previous studies were found using the search terms "enterovirus 71" and "epidemiology" or "pathogenesis" or "molecular epidemiology" or "vaccine" in Medline and PubMed. Articles that were not published in the English language, manuscripts without an abstract, and opinion articles were excluded from the review. The reported epidemiology of cases caused by EV71 infection varied from country to country; seasonal variations in incidence were observed. Most cases of EV71 infection that resulted in hospitalization for complications occurred in children less than five years old. The brainstem was the most likely major target of EV71 infection. The emergence of the EV71 epidemic in the Asia-Pacific region has been associated with the circulation of different genetic lineages (genotypes B3, B4, C1, C2, and C4) that appear to be undergoing rapid evolutionary changes. The relationship between the gene structure of the EV71 virus and the factors that ensure its survival, circulation, and evasion of immunity is still unknown. EV71 infection has emerged as an important global public health problem. Vaccine development, including the development of inactivated whole-virus live attenuated, subviral particles, and DNA vaccines, has been progressing. PMID:27618078

  15. Valproate attenuates the development of morphine antinociceptive tolerance.

    Science.gov (United States)

    Dobashi, Tamae; Tanabe, Serabi; Jin, Hisayo; Nishino, Takashi; Aoe, Tomohiko

    2010-11-19

    Morphine is a potent opioid analgesic. Repeated administration of morphine induces tolerance, thus reducing the effectiveness of analgesic treatment. Although some adjuvant analgesics can increase morphine analgesia, the precise molecular mechanism behind their effects remains unclear. Opioids bind to the mu opioid receptor (MOR). Morphine tolerance may be derived from alterations in the intracellular signal transduction after MOR activation. Chronic morphine treatment activates glycogen synthase kinase 3β (GSK3β), whose inhibition diminishes morphine tolerance. Valproate is widely prescribed as an anticonvulsant and a mood stabilizer for bipolar disorders because it increases the amount of γ-aminobutyric acid (GABA) in the central nervous system. Although the activation of GABAergic neurons may be responsible for the chief pharmacologic effect of valproate, recent studies have shown that valproate also suppresses GSK3β activity. We examined the effect of valproate on the development of morphine antinociceptive tolerance in a mouse model of thermal injury. Mice were treated with morphine alone or with morphine and valproate twice daily for 5 days. The resulting antinociceptive effects were assessed using a hot plate test. While mice treated with morphine developed tolerance, co-administration of valproate attenuated the development of tolerance and impaired the activation of GSK3β in mice brains. Valproate alone did not show analgesic effects; nevertheless, it functioned as an adjuvant analgesic to prevent the development of morphine tolerance. These results suggest that the modulation of GSK3β activity by valproate may be useful and may play a role in the prevention of morphine tolerance. PMID:20816918

  16. Intellectual property rights and challenges for development of affordable human papillomavirus, rotavirus and pneumococcal vaccines: Patent landscaping and perspectives of developing country vaccine manufacturers.

    Science.gov (United States)

    Chandrasekharan, Subhashini; Amin, Tahir; Kim, Joyce; Furrer, Eliane; Matterson, Anna-Carin; Schwalbe, Nina; Nguyen, Aurélia

    2015-11-17

    The success of Gavi, the Vaccine Alliance depends on the vaccine markets providing appropriate, affordable vaccines at sufficient and reliable quantities. Gavi's current supplier base for new and underutilized vaccines, such as the human papillomavirus (HPV), rotavirus, and the pneumococcal conjugate vaccine is very small. There is growing concern that following globalization of laws on intellectual property rights (IPRs) through trade agreements, IPRs are impeding new manufacturers from entering the market with competing vaccines. This article examines the extent to which IPRs, specifically patents, can create such obstacles, in particular for developing country vaccine manufacturers (DCVMs). Through building patent landscapes in Brazil, China, and India and interviews with manufacturers and experts in the field, we found intense patenting activity for the HPV and pneumococcal vaccines that could potentially delay the entry of new manufacturers. Increased transparency around patenting of vaccine technologies, stricter patentability criteria suited for local development needs and strengthening of IPRs management capabilities where relevant, may help reduce impediments to market entry for new manufacturers and ensure a competitive supplier base for quality vaccines at sustainably low prices. PMID:26368398

  17. Overview of developments in the last 10-15 years in recombinant vaccines

    Science.gov (United States)

    This introductory talk will describe the various types of recombinant DNA vaccines that have been developed for the poultry industry. The talk will not discuss the efficacy of specific recombinant DNA vaccines. Instead, I will focus on describing how various recombinant vaccines are made and some ad...

  18. The Ectodomain of Glycoprotein from the Candid#1 Vaccine Strain of Junin Virus Rendered Machupo Virus Partially Attenuated in Mice Lacking IFN-αβ/γ Receptor.

    Science.gov (United States)

    Koma, Takaaki; Huang, Cheng; Aronson, Judith F; Walker, Aida G; Miller, Milagros; Smith, Jeanon N; Patterson, Michael; Paessler, Slobodan

    2016-08-01

    Machupo virus (MACV), a New World arenavirus, is the etiological agent of Bolivian hemorrhagic fever (BHF). Junin virus (JUNV), a close relative, causes Argentine hemorrhagic fever (AHF). Previously, we reported that a recombinant, chimeric MACV (rMACV/Cd#1-GPC) expressing glycoprotein from the Candid#1 (Cd#1) vaccine strain of JUNV is completely attenuated in a murine model and protects animals from lethal challenge with MACV. A rMACV with a single F438I substitution in the transmembrane domain (TMD) of GPC, which is equivalent to the F427I attenuating mutation in Cd#1 GPC, was attenuated in a murine model but genetically unstable. In addition, the TMD mutation alone was not sufficient to fully attenuate JUNV, indicating that other domains of the GPC may also contribute to the attenuation. To investigate the requirement of different domains of Cd#1 GPC for successful attenuation of MACV, we rescued several rMACVs expressing the ectodomain of GPC from Cd#1 either alone (MCg1), along with the TMD F438I substitution (MCg2), or with the TMD of Cd#1 (MCg3). All rMACVs exhibited similar growth curves in cultured cells. In mice, the MCg1 displayed significant reduction in lethality as compared with rMACV. The MCg1 was detected in brains and spleens of MCg1-infected mice and the infection was associated with tissue inflammation. On the other hand, all animals survived MCg2 and MCg3 infection without detectable levels of virus in various organs while producing neutralizing antibody against Cd#1. Overall our data suggest the indispensable role of each GPC domain in the full attenuation and immunogenicity of rMACV/Cd#1 GPC. PMID:27580122

  19. MALVAC 2012 scientific forum: accelerating development of second-generation malaria vaccines

    OpenAIRE

    Vannice Kirsten S; Brown Graham V; Akanmori Bartholomew D; Moorthy Vasee S

    2012-01-01

    Abstract The World Health Organization (WHO) convened a malaria vaccines committee (MALVAC) scientific forum from 20 to 21 February 2012 in Geneva, Switzerland, to review the global malaria vaccine portfolio, to gain consensus on approaches to accelerate second-generation malaria vaccine development, and to discuss the need to update the vision and strategic goal of the Malaria Vaccine Technology Roadmap. This article summarizes the forum, which included reviews of leading Plasmodium falcipar...

  20. Development and Evidence for Efficacy of CMV Glycoprotein B Vaccine with MF59 Adjuvant

    OpenAIRE

    Pass, Robert F.

    2009-01-01

    A vaccine comprised of recombinant cytomegalovirus (CMV) envelope glycoprotein B (gB) with MF59 adjuvant developed in the 1990s recently was recently found to have efficacy for prevention of CMV infection in a phase 2 clinical trial in young mothers. This review briefly considers the rationale for gB as a vaccine antigen, the history of this CMV gB vaccine and the data supporting vaccine efficacy.

  1. The development and prospect of the vaccine against Schistosoma japonicum%日本血吸虫疫苗的研究进展与展望

    Institute of Scientific and Technical Information of China (English)

    景英霞; 邵筱

    2010-01-01

    The study on vaccine against Schistosoma has been included into the program of the treat-ment and prevention on the major diseases of WHO and our country with a great progress. The history of the study on vaccines against Schistosoma has passed from dead vaccine, attenuated vaccine, sub-unit vaccine,gene engineered vaccine, nucleic acid vaccine to muhivalent affiliate vaccine. Recently, the research progress on immunologic mechanism of Schiswsoma and the genome of Schistosoma has played a very important role in the research and development of vaccine against Schistosoma. This article reviewed the development of vaccine against Schistosoma japonicum in recent 10 years.%血吸虫疫苗的研究已经纳入了WHO和我国主要疾病防治规划,并且取得了很大的进展.血吸虫疫苗的研究历史经历了从死疫苗、致弱活疫苗、亚单仲疫苗、基因工程疫苗、核酸疫苗到多价联合疫苗等的探索过程.近年来开展的血吸虫免疫机制和血吸虫基因组的研究对血吸虫疫苗的研制起到了积极的推动作用.该文主要对日本血吸虫疫苗近十年的研究进展作一综述.

  2. 国产甲型肝炎减毒活疫苗和灭活疫苗安全性评价%Evaluation on Safety of Domestic Hepatitis A Attenuated Live Vaccine and Hepatitis A Inactivated Vaccine

    Institute of Scientific and Technical Information of China (English)

    张晓曙; 安婧; 刘建锋; 付鸿; 高丽; 李慧

    2012-01-01

    Objective To evaluate safety of domestic hepatitis A attenuated live vaccine (HepA-L) and hepatitis A inactivated vaccine (HepA-I), and provide reference for emergency vaccination after hepatitis A outbreaks. Methods 493 children aged 6-9 years confirmed negative with antibody to hepatitis A virus (Anti-HAV) produced by Abbott. U.S were divided randomly into four groups. Group A were vaccinated with domestic HepA-L, group B were vaccinated with domestic HepA-I, group C were vaccinated with hepatitis B vaccine made by recombinant deoxyribonucleic acid technigues in sacchararomyces cerevisiae yeast ( HepB-SCY ) as negative control and group D were vaccinated HepA-I produced by GlaxoSmithKline Biologicals S.A. (GSK)as positive control. The adverse events following immunization (AEFIs) were observed after 30 minutes, 24, 48 and 72 hours after vaccination with double-blind method. Results The main AEFIs were fever, local pain and scleroma. There were no other severe AEFIs. The rate of AEFIs was 13.95% in Group A, 15.25% in group B, 16.80% in group C and 25.62% in group D. There were no statistical differences between different groups (x2=6.953, P=0.073). Conclusion Domestic HepA-L, domestic HepA-I and imported HepA-I are Safe.%目的 评价国产甲型病毒性肝炎(甲肝)减毒活疫苗(Hepatitis A Attenuated Live Vaccine,HepA-L)和灭活疫苗(Hepatitis A Inactivated Vaccine,HepA-I)的安全性,为开展甲肝爆发疫情应急接种提供参考.方法 用美国雅培(Abbott)公司生产的抗甲肝病毒抗体(Antibody to Hepatitis A Virus,Anti-HAV)试剂,筛查未感染HAV的6~9岁儿童.将入选对象随机分为4组,分别接种国产HepA-L和国产HepA-I,以国产的重组乙型肝炎疫苗(酿酒酵母)(Hepatitis B Vaccine Made by Recombinant Deoxyribonucleic Acid Technigues in Sacchararomyces Cerevisiae Yeast,HepB-SCY)为阴性对照,以GlaxoSmithKline Biologicals S.A.(GSK)生产的HepA-I为阳性对照,采取随机双盲方法,观察接种疫苗后30min

  3. Development of vaccines against Ornithodoros soft ticks: An update.

    Science.gov (United States)

    Díaz-Martín, Verónica; Manzano-Román, Raúl; Obolo-Mvoulouga, Prosper; Oleaga, Ana; Pérez-Sánchez, Ricardo

    2015-04-01

    Ticks are parasites of great medical and veterinary importance since they are vectors of numerous pathogens that affect humans, livestock and pets. Among the argasids, several species of the genus Ornithodoros transmit serious diseases such as tick-borne human relapsing fever (TBRF) and African Swine Fever (ASF). In particular, Ornithodoros erraticus is the main vector of these two diseases in the Mediterranean while O. moubata is the main vector in Africa. The presence of these Ornithodoros ticks in domestic and peridomestic environments may greatly hinder the eradication of TBRF and ASF from endemic areas. In addition, there is a constant threat of reintroduction and spreading of ASF into countries from where it has been eradicated (Spain and Portugal) or where it was never present (the Caucasus, Russia and Eastern Europe). In these countries, the presence of Ornithodoros vectors could have a tremendous impact on ASF transmission and long-term maintenance. Therefore, elimination of these ticks from at least synanthropic environments would contribute heavily to the prevention and control of the diseases they transmit. Tick control is a difficult task and although several methods for such control have been used, none of them has been fully effective against all ticks and the problems they cause. Nevertheless, immunological control using anti-tick vaccines offers an attractive alternative to the traditional use of acaricides. The aim of the present paper is to offer a brief overview of the current status in control measure development for Ornithodoros soft ticks, paying special attention to the development of vaccines against O. erraticus and O. moubata. Thus, our contribution includes an analysis of the chief attributes that the ideal antigens for an anti-tick vaccine should have, an exhaustive compilation and analysis of the scant anti-soft tick vaccine trials carried out to date using both concealed and salivary antigens and, finally, a brief description of the

  4. Gamma irradiation attenuation of Anaplasma Marginale and its possible use as vaccine against bovine anaplasmosis

    International Nuclear Information System (INIS)

    Bovine Anaplasmosis is one of the limiting in the cattle development at Colombia and others tropical countries. Bovine Anaplasmosis is an infectious disease caused by a microorganism called Anaplasma Marginale, it with invades the red globules producing erythrofagocitosis. In this job, were irradiated with different gamma beam intensity; microorganisms of Anaplasma Marginale, those which were used as innocuous. Animals of the groups (I,II,III) presented good protection against the disease; animals of the Group IV presented mild symptoms with subsequent recovery and strong symptoms

  5. 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

  6. CXCR4 Antagonism Attenuates the Development of Diabetic Cardiac Fibrosis.

    Directory of Open Access Journals (Sweden)

    Po-Yin Chu

    Full Text Available Heart failure (HF is an increasingly recognized complication of diabetes. Cardiac fibrosis is an important causative mechanism of HF associated with diabetes. Recent data indicate that inflammation may be particularly important in the pathogenesis of cardiovascular fibrosis. We sought to determine the mechanism by which cardiac fibrosis develops and to specifically investigate the role of the CXCR4 axis in this process. Animals with type I diabetes (streptozotocin treated mice or type II diabetes (Israeli Sand-rats and controls were randomized to treatment with a CXCR4 antagonist, candesartan or vehicle control. Additional groups of mice also underwent bone marrow transplantation (GFP+ donor marrow to investigate the potential role of bone marrow derived cell mobilization in the pathogenesis of cardiac fibrosis. Both type I and II models of diabetes were accompanied by the development of significant cardiac fibrosis. CXCR4 antagonism markedly reduced cardiac fibrosis in both models of diabetes, similar in magnitude to that seen with candesartan. In contrast to candesartan, the anti-fibrotic actions of CXCR4 antagonism occurred in a blood pressure independent manner. Whilst the induction of diabetes did not increase the overall myocardial burden of GFP+ cells, it was accompanied by an increase in GFP+ cells expressing the fibroblast marker alpha-smooth muscle actin and this was attenuated by CXCR4 antagonism. CXCR4 antagonism was also accompanied by increased levels of circulating regulatory T cells. Taken together the current data indicate that pharmacological inhibition of CXCR4 significantly reduces diabetes induced cardiac fibrosis, providing a potentially important therapeutic approach.

  7. Human biomarkers: can they help us to develop a new tuberculosis vaccine?

    Science.gov (United States)

    Fletcher, Helen A; Dockrell, Hazel M

    2016-06-01

    The most effective intervention for the control of infectious disease is vaccination. The BCG vaccine, the only licensed vaccine for the prevention of tuberculosis (TB) disease, is only partially effective and a new vaccine is urgently needed. Biomarkers can aid the development of new TB vaccines through discovery of immune mechanisms, early assessment of vaccine immunogenicity or vaccine take and identification of those at greatest risk of disease progression for recruitment into smaller, targeted efficacy trials. The ultimate goal, however, remains a biomarker of TB vaccine efficacy that can be used as a surrogate for a TB disease end point and there remains an urgent need for further research in this area. PMID:27203133

  8. The global roadmap for advancing development of vaccines against sexually transmitted infections: Update and next steps.

    Science.gov (United States)

    Gottlieb, Sami L; Deal, Carolyn D; Giersing, Birgitte; Rees, Helen; Bolan, Gail; Johnston, Christine; Timms, Peter; Gray-Owen, Scott D; Jerse, Ann E; Cameron, Caroline E; Moorthy, Vasee S; Kiarie, James; Broutet, Nathalie

    2016-06-01

    In 2014, the World Health Organization, the US National Institutes of Health, and global technical partners published a comprehensive roadmap for development of new vaccines against sexually transmitted infections (STIs). Since its publication, progress has been made in several roadmap activities: obtaining better epidemiologic data to establish the public health rationale for STI vaccines, modeling the theoretical impact of future vaccines, advancing basic science research, defining preferred product characteristics for first-generation vaccines, and encouraging investment in STI vaccine development. This article reviews these overarching roadmap activities, provides updates on research and development of individual vaccines against herpes simplex virus, Chlamydia trachomatis, Neisseria gonorrhoeae, and Treponema pallidum, and discusses important next steps to advance the global roadmap for STI vaccine development. PMID:27105564

  9. Evidence that radio-sensitive cells are central to skin-phase protective immunity in CBA/Ca mice vaccinated with radiation-attenuated cercariae of Schistosoma mansoni as well as in naive mice protected with vaccine serum

    Energy Technology Data Exchange (ETDEWEB)

    Delgado, V.S.; McLaren, D.J. (National Inst. for Medical Research, London (UK))

    1990-02-01

    Naive CBA/Ca mice and CBA/ca mice vaccinated 4 weeks previously with radiation-attenuated cercariae of Schistosoma mansoni were subjected to 550 rad of whole body (gamma) irradiation and then challenged 3 days later with normal cercariae. The perfusion recovery data showed that this procedure reduced the primary worm burden in naive mice by 22% and the challence worm burden in vaccinated mice by 82%. Irradiation also ablated the peripheral blood leucocytes of both mouse groups by 90-100% at the time of challenge. Histological data revealed that such treatment caused a dramatic change in number, size and leucocyte composition of cutaneous inflammatory skin reactions that characterize challenged vacccinated mice and are known to entrap invading larvae; cutaneous eosinophils were preferentially abolished by this treatment. Polyvaccine mouse serum that conferred protection passively upon naive recipient mice, failed to protect naive/irradiated mice when administered by the same protocol. Distraction of macrophages by treatment of mice with silica did not affect the establishment of a primary worm burden and reduced the protection exhibited by vaccinated mice by only 16%. These data indicade that radio-sensitive cells are important to both innate and specific acquired resistance in this mouse model and that macrophages contribute only marginally to the expression of vaccine immunity. (author).

  10. Evidence that radio-sensitive cells are central to skin-phase protective immunity in CBA/Ca mice vaccinated with radiation-attenuated cercariae of Schistosoma mansoni as well as in naive mice protected with vaccine serum

    International Nuclear Information System (INIS)

    Naive CBA/Ca mice and CBA/ca mice vaccinated 4 weeks previously with radiation-attenuated cercariae of Schistosoma mansoni were subjected to 550 rad of whole body (gamma) irradiation and then challenged 3 days later with normal cercariae. The perfusion recovery data showed that this procedure reduced the primary worm burden in naive mice by 22% and the challence worm burden in vaccinated mice by 82%. Irradiation also ablated the peripheral blood leucocytes of both mouse groups by 90-100% at the time of challenge. Histological data revealed that such treatment caused a dramatic change in number, size and leucocyte composition of cutaneous inflammatory skin reactions that characterize challenged vacccinated mice and are known to entrap invading larvae; cutaneous eosinophils were preferentially abolished by this treatment. Polyvaccine mouse serum that conferred protection passively upon naive recipient mice, failed to protect naive/irradiated mice when administered by the same protocol. Distraction of macrophages by treatment of mice with silica did not affect the establishment of a primary worm burden and reduced the protection exhibited by vaccinated mice by only 16%. These data indicade that radio-sensitive cells are important to both innate and specific acquired resistance in this mouse model and that macrophages contribute only marginally to the expression of vaccine immunity. (author)

  11. Malaria vaccine development in Europe-preparing for the future : Workshop report

    OpenAIRE

    Viebig, N. K.; D'Alessio, F.; Draper, S. J.; Sim, B. K. L.; Mordmuller, B.; Bowyer, P. W.; Luty, Adrian; Jungbluth, S.; Chitnis, C.E.; Hill, A. V. S.; Kremsner, P.; Craig, A. G.; Kocken, C. H. M.; Leroy, O

    2015-01-01

    The deployment of a safe and effective malaria vaccine will be an important tool for the control of malaria and the reduction in malaria deaths. With the launch of the 2030 Malaria Vaccine Technology Roadmap, the malaria community has updated the goals and priorities for the development of such a vaccine and is now paving the way for a second phase of malaria vaccine development. During a workshop in Brussels in November 2014, hosted by the European Vaccine Initiative, key players from the Eu...

  12. Vaccine production training to develop the workforce of foreign institutions supported by the BARDA influenza vaccine capacity building program.

    Science.gov (United States)

    Tarbet, E Bart; Dorward, James T; Day, Craig W; Rashid, Kamal A

    2013-03-15

    In the event of an influenza pandemic, vaccination will be the best method to limit virus spread. However, lack of vaccine biomanufacturing capacity means there will not be enough vaccine for the world's population. The U.S. Department of Health and Human Services, Biomedical Advanced Research and Development Authority (BARDA) provides support to the World Health Organization to enhance global vaccine production capacity in developing countries. However, developing a trained workforce in some of those countries is necessary. Biomanufacturing is labor-intensive, requiring unique skills not found in traditional academic programs. Employees must understand the scientific basis of biotechnology, operate specialized equipment, and work in an environment regulated by good manufacturing practices (cGMP). Therefore, BARDA supported development of vaccine biomanufacturing training at Utah State University. The training consisted of a three-week industry-focused course for participants from institutions supported by the BARDA and WHO influenza vaccine production capacity building program. The curriculum was divided into six components: (1) biosafety, (2) cell culture and growth of cells in bioreactors, (3) virus assays and inactivation, (4) scale-up strategies, (5) downstream processing, and (6) egg- and cell-based vaccine production and cGMP. Lectures were combined with laboratory exercises to provide a balance of theory and hands-on training. The initial course included sixteen participants from seven countries including: Egypt, Romania, Russia, Serbia, South Korea, Thailand, and Vietnam. The participant's job responsibilities included: Production, Quality Control, Quality Assurance, and Research; and their education ranged from bachelors to doctoral level. Internal course evaluations utilized descriptive methods including surveys, observation of laboratory activities, and interviews with participants. Generally, participants had appropriate academic backgrounds, but

  13. Development of electrothermal actuation based planar variable optical attenuators (VOAs)

    International Nuclear Information System (INIS)

    Several sorts of MEMS (Microelectromechanical Systems) based have been demonstrated by using electrostatic actuation scheme up to date. The comb drive and parallel plate are the two most common electrostatic actuators that have been well studied in variable optical attenuator (VOA) applications. In addition to the known retro-reflection type of optical attenuation being realized by our new devices driven by electrothermal actuators in present study, a novel planar tilted mirror with rotational and translation moving capability is proposed by using electrothermal actuators as well. Using electrothermal actuators to provide said planar tilted mirror with rotational and translational displacement has granted us a more efficient way to perform the light attenuation for in-plane structure. The static and transient characteristics of devices operated at ambient room temperature environment show good repeatability and stability

  14. Gamma ray attenuation in a developed borate glassy system

    International Nuclear Information System (INIS)

    Measurements and calculations of gamma ray attenuation coefficients in glass barriers of xBaO–5ZnO–5MgO–14Na2O–-1Li2O–(75−x)B2O3, previously prepared by the melt-quenching technique [1], were performed for γ-ray of energies 121.8, 244.7, 344.14, 661.66, 778.7, 974, 1086.7, 1173.24, 1332.5, and 1407.9 keV; which emitted from 152Eu, 137Cs, and 60Co radioactive gamma ray sources. The transmitted γ-rays were detected by 3″×3″ and 5″×5″ NaI (Tl) scintillation γ-ray spectrometers, and a highly calibrated survey meter. The mass attenuation coefficients of γ-rays (σ(E)) were deduced from the attenuation curves, while the WinXCom computer program (version 3.1) was used to calculate the mass attenuation coefficients of γ-rays for such energies at different barium concentrations of a glassy system. A good agreement between both experimental and theoretical results was achieved as well as results obtained by other workers in similar field. - Highlights: • Design new glass system can be used as nuclear radiation shielding material. • Three different systems were used to measure γ-ray attenuation coefficients. • The γ-ray attenuation coefficients in this glass system were measured for 10 γ-energy lines. • Good agreement between experimental, theoretical, and results by other workers have been achieved. • Improvement of σ and HVL by increasing BaO concentration up to 50% in our glassy system

  15. Vaccine development in Staphylococcus aureus: taking the biofilm phenotype into consideration

    OpenAIRE

    Harro, Janette M; Peters, Brian M.; O'May, Graeme A.; Archer, Nathan; Kerns, Patrick; Prabhakara, Ranjani; Shirtliff, Mark E

    2010-01-01

    Vaccine development against pathogenic bacteria is an imperative initiative as bacteria are gaining resistance to current antimicrobial therapies and few novel antibiotics are being developed. Candidate antigens for vaccine development can be identified by a multitude of high-throughput technologies that were accelerated by access to complete genomes. While considerable success has been achieved in vaccine development against bacterial pathogens, many species with multiple virulence factors a...

  16. Gamma ray attenuation in a developed borate glassy system

    Science.gov (United States)

    Saeed, Aly; El shazly, R. M.; Elbashar, Y. H.; Abou El-azm, A. M.; El-Okr, M. M.; Comsan, M. N. H.; Osman, A. M.; Abdal-monem, A. M.; El-Sersy, A. R.

    2014-09-01

    Measurements and calculations of gamma ray attenuation coefficients in glass barriers of xBaO-5ZnO-5MgO-14Na2O--1Li2O-(75-x)B2O3, previously prepared by the melt-quenching technique [1], were performed for γ-ray of energies 121.8, 244.7, 344.14, 661.66, 778.7, 974, 1086.7, 1173.24, 1332.5, and 1407.9 keV; which emitted from 152Eu, 137Cs, and 60Co radioactive gamma ray sources. The transmitted γ-rays were detected by 3″×3″ and 5″×5″ NaI (Tl) scintillation γ-ray spectrometers, and a highly calibrated survey meter. The mass attenuation coefficients of γ-rays (σ(E) were deduced from the attenuation curves, while the WinXCom computer program (version 3.1) was used to calculate the mass attenuation coefficients of γ-rays for such energies at different barium concentrations of a glassy system. A good agreement between both experimental and theoretical results was achieved as well as results obtained by other workers in similar field.

  17. Human-animal chimeras for vaccine development: an endangered species or opportunity for the developing world?

    Directory of Open Access Journals (Sweden)

    Daar Abdallah S

    2010-05-01

    Full Text Available Abstract Background In recent years, the field of vaccines for diseases such as Human Immunodeficiency Virus (HIV which take a heavy toll in developing countries has faced major failures. This has led to a call for more basic science research, and development as well as evaluation of new vaccine candidates. Human-animal chimeras, developed with a 'humanized' immune system could be useful to study infectious diseases, including many neglected diseases. These would also serve as an important tool for the efficient testing of new vaccine candidates to streamline promising candidates for further trials in humans. However, developing human-animal chimeras has proved to be controversial. Discussion Development of human-animal chimeras for vaccine development has been slowed down because of opposition by some philosophers, ethicists and policy makers in the west-they question the moral status of such animals, and also express discomfort about transgression of species barriers. Such opposition often uses a contemporary western world view as a reference point. Human-animal chimeras are often being created for diseases which cause significantly higher morbidity and mortality in the developing world as compared to the developed world. We argue in our commentary that given this high disease burden, we should look at socio-cultural perspectives on human-animal chimera like beings in the developing world. On examination, it's clear that such beings have been part of mythology and cultural descriptions in many countries in the developing world. Summary To ensure that important research on diseases afflicting millions like malaria, HIV, Hepatitis-C and dengue continues to progress, we recommend supporting human-animal chimera research for vaccine development in developing countries (especially China and India which have growing technical expertise in the area. The negative perceptions in some parts of the west about human-animal chimeras can be used as an

  18. Hepatitis virus vaccines: present status.

    OpenAIRE

    Krugman, S.

    1982-01-01

    During the past decade there has been extraordinary progress toward the development of vaccines for the prevention of type A and type B hepatitis. The successful propagation of hepatitis A virus in cell culture in 1979 was followed by the preparation of experimental live attenuated hepatitis A vaccines that have been shown to induce antibody in marmosets and chimpanzees and protect immunized marmosets against challenge with hepatitis A virus. The first human immunization trials will begin in ...

  19. Current developments in avian influenza vaccines, including safety of vaccinated birds as food.

    Science.gov (United States)

    Swayne, D E; Suarez, D L

    2007-01-01

    Until recently, most vaccines against avian influenza were based on oil-emulsified inactivated low- or high-pathogenicity viruses. Now, recombinant fowl pox and avian paramyxovirus type 1 vaccines with avian influenza H5 gene inserts (+ or - N1 gene insert) are available and licensed. New technologies might overcome existing limitations to make available vaccines that can be grown in tissue culture systems for more rapid production; provide optimized protection, as a result of closer genetic relations to field viruses; allow mass administration by aerosol, in drinking-water or in ovo; and allow easier strategies for identifying infected birds within vaccinated populations (DIVA). The technologies include avian influenza viruses with partial gene deletions, avian influenza-Newcastle disease virus chimeras, vectored vaccines such as adenoviruses and Marek's disease virus, and subunit vaccines. These new methods should be licensed only after their purity, safety, efficacy and potency against avian influenza viruses have been demonstrated, and, for live vectored vaccines, restriction of viral transmission to unvaccinated birds. Use of vaccines in countries affected by highly pathogenic avian influenza will not only protect poultry but will provide additional safety for consumers. Experimental studies have shown that birds vaccinated against avian influenza have no virus in meat and minimal amounts in eggs after HPAI virus challenge, and that replication and shedding from their respiratory and alimentary tracts is greatly reduced. PMID:18411943

  20. Recent advances in the development of vaccines for tuberculosis

    OpenAIRE

    Ahsan, Mohamed Jawed

    2015-01-01

    Tuberculosis (Tb) continues to be a dreadful infection worldwide with nearly 1.5 million deaths in 2013. Furthermore multi/extensively drug-resistant Tb (MDR/XDR-Tb) worsens the condition. Recently approved anti-Tb drugs (bedaquiline and delamanid) have the potential to induce arrhythmia and are recommended in patients with MDR-Tb when other alternatives fail. The goal of elimination of Tb by 2050 will not be achieved without an effective new vaccine. The recent advancement in the development...

  1. Progress of vaccine and drug development for Ebola preparedness

    OpenAIRE

    Choi, Woo Young; Hong, Kee-Jong; Hong, Joo Eun; Lee, Won-Ja

    2015-01-01

    Since the first case of Ebola virus disease (EVD) in Guinea was reported in March 2014 by World Health Organization (WHO), the outbreak has continued through the year and the total number of 19,065 patients was reported as the confirmed or suspected in the EVD-affected countries. Among the cases, 7,388 patients were reported death by 19 December. Currently, available therapeutics to treat the infected patients or vaccines to prevent people from infection is not developed yet while viral diagn...

  2. The clinical development process for a novel preventive vaccine: An overview

    Science.gov (United States)

    Singh, K; Mehta, S

    2016-01-01

    Each novel vaccine candidate needs to be evaluated for safety, immunogenicity, and protective efficacy in humans before it is licensed for use. After initial safety evaluation in healthy adults, each vaccine candidate follows a unique development path. This article on clinical development gives an overview on the development path based on the expectations of various guidelines issued by the World Health Organization (WHO), the European Medicines Agency (EMA), and the United States Food and Drug Administration (USFDA). The manuscript describes the objectives, study populations, study designs, study site, and outcome(s) of each phase (Phase I-III) of a clinical trial. Examples from the clinical development of a malaria vaccine candidate, a rotavirus vaccine, and two vaccines approved for human papillomavirus (HPV) have also been discussed. The article also tabulates relevant guidelines, which can be referred to while drafting the development path of a novel vaccine candidate. PMID:26732191

  3. Development of antifertility vaccine using sperm specific proteins

    Directory of Open Access Journals (Sweden)

    A H Bandivdekar

    2014-01-01

    Full Text Available Sperm proteins are known to be associated with normal fertilization as auto- or iso-antibodies to these proteins may cause infertility. Therefore, sperm proteins have been considered to be the potential candidate for the development of antifertility vaccine. Some of the sperm proteins proved to be promising antigens for contraceptive vaccine includes lactate dehydrogenase (LDH-C4, protein hyaluronidase (PH-20, and Eppin. Immunization with LDH-C4 reduced fertility in female baboons but not in female cynomolgus macaques. Active immunization with PH-20 resulted in 100 per cent inhibition of fertility in male guinea pigs but it induced autoimmune orchitis. Immunization with Eppin elicited high antibody titres in 78 per cent of immunized monkeys and induced infertility but the immunopathological effect of immunization was not examined. Human sperm antigen (80kDa HSA is a sperm specific, highly immunogenic and conserved sperm protein. Active immunization with 80kDa HSA induced immunological infertility in male and female rats. Partial N-terminal amino acid sequence of 80kDa HSA (Peptide NT and its peptides (Peptides 1, 2, 3 and 4 obtained by enzymatic digestion did not show homology with any of the known proteins in gene bank. Peptides NT, 1, 2 and 4 were found to mimic immunobiological activity of native protein. Passive administration of antibodies to peptides NT, 1, 2 and 4 induced infertility in male and female rats and peptide 1 was found to be most effective in suppressing fertility. Active immunization with keyhole limpet haemocynin (KLH conjugated synthetic peptide 1 impaired fertility in all the male rabbits and six of the seven male marmosets. The fertility was restored following decline in antibody titre. All these findings on 80kDA HAS suggest that the synthetic Peptide-1 of 80kDa HSA is the promising candidate for development of male contraceptive vaccine.

  4. Development of antifertility vaccine using sperm specific proteins.

    Science.gov (United States)

    Bandivdekar, A H

    2014-11-01

    Sperm proteins are known to be associated with normal fertilization as auto- or iso-antibodies to these proteins may cause infertility. Therefore, sperm proteins have been considered to be the potential candidate for the development of antifertility vaccine. Some of the sperm proteins proved to be promising antigens for contraceptive vaccine includes lactate dehydrogenase (LDH-C4), protein hyaluronidase (PH-20), and Eppin. Immunization with LDH-C4 reduced fertility in female baboons but not in female cynomolgus macaques. Active immunization with PH-20 resulted in 100 per cent inhibition of fertility in male guinea pigs but it induced autoimmune orchitis. Immunization with Eppin elicited high antibody titres in 78 per cent of immunized monkeys and induced infertility but the immunopathological effect of immunization was not examined. Human sperm antigen (80 kDa HSA) is a sperm specific, highly immunogenic and conserved sperm protein. Active immunization with 80 kDa HSA induced immunological infertility in male and female rats. Partial N-terminal amino acid sequence of 80 kDa HSA (Peptide NT) and its peptides (Peptides 1, 2, 3 and 4) obtained by enzymatic digestion did not show homology with any of the known proteins in gene bank. Peptides NT, 1, 2 and 4 were found to mimic immunobiological activity of native protein. Passive administration of antibodies to peptides NT, 1, 2 and 4 induced infertility in male and female rats and peptide 1 was found to be most effective in suppressing fertility. Active immunization with keyhole limpet haemocynin (KLH) conjugated synthetic peptide 1 impaired fertility in all the male rabbits and six of the seven male marmosets. The fertility was restored following decline in antibody titre. All these findings on 80 kDA HAS suggest that the synthetic Peptide-1 of 80 kDa HSA is the promising candidate for development of male contraceptive vaccine. PMID:25673547

  5. Combination recombinant simian or chimpanzee adenoviral vectors for vaccine development.

    Science.gov (United States)

    Cheng, Cheng; Wang, Lingshu; Ko, Sung-Youl; Kong, Wing-Pui; Schmidt, Stephen D; Gall, Jason G D; Colloca, Stefano; Seder, Robert A; Mascola, John R; Nabel, Gary J

    2015-12-16

    Recombinant adenoviral vector (rAd)-based vaccines are currently being developed for several infectious diseases and cancer therapy, but pre-existing seroprevalence to such vectors may prevent their use in broad human populations. In this study, we investigated the potential of low seroprevalence non-human primate rAd vectors to stimulate cellular and humoral responses using HIV/SIV Env glycoprotein (gp) as the representative antigen. Mice were immunized with novel simian or chimpanzee rAd (rSAV or rChAd) vectors encoding HIV gp or SIV gp by single immunization or in heterologous prime/boost combinations (DNA/rAd; rAd/rAd; rAd/NYVAC or rAd/rLCM), and adaptive immunity was assessed. Among the rSAV and rChAd tested, rSAV16 or rChAd3 vector alone generated the most potent immune responses. The DNA/rSAV regimen also generated immune responses similar to the DNA/rAd5 regimen. rChAd63/rChAd3 and rChAd3 /NYVAC induced similar or even higher levels of CD4+ and CD8+ T-cell and IgG responses as compared to rAd28/rAd5, one of the most potent combinations of human rAds. The optimized vaccine regimen stimulated improved cellular immune responses and neutralizing antibodies against HIV compared to the DNA/rAd5 regimen. Based on these results, this type of novel rAd vector and its prime/boost combination regimens represent promising candidates for vaccine development. PMID:26514419

  6. Development of stable influenza vaccine powder formulations : Challenges and possibilities

    NARCIS (Netherlands)

    Amorij, J-P; Huckriede, A; Wilschut, J; Frijlink, H W; Hinrichs, W L J

    2008-01-01

    Influenza vaccination represents the cornerstone of influenza prevention. However, today all influenza vaccines are formulated as liquids that are unstable at ambient temperatures and have to be stored and distributed under refrigeration. In order to stabilize influenza vaccines, they can be brought

  7. Effect of cell mediated immunity regulation of duck enhanced by duck IFN-α eukaryon expression plasmid and inoculated with DPV attenuated vaccine by gene-gun

    Institute of Scientific and Technical Information of China (English)

    Zhiping CHENG; Anchun CHENG; Mingshu WANG; Bin CHEN; Chuang LIU; Kun DUAN; Xue ZHOU; Xiaoyue CHEN

    2008-01-01

    In order to study the effect of cell mediated immunity regulation of duck IFN-α eukaryon expression plasmid (pcDNA-SDIFN-α) on duck plague virus (DPV)attenuated vaccine in ducks,pcDNA-SDIFN-α was administered to 28-day-old ducks at doses of 1,3 and 6 μg per duck,respectively,by gene-gun.PBS and empty vector pcDNA were used as control.Fifteen days later,all ducks were injected with DPV attenuated vaccine and blood samples were collected at 3,7,14,21,28,35,49,63 and 84 days after injection.T-lymphocyte proliferation tests (MTT) were used to detect the T-lymphocyte proliferation in the peripheral blood (PBL) of ducks.Blood samples collected at 7,14,21,28,35 and 49 days after injection were detected by fluorescence-activated cell sorter (FACS) for recording the number of CD3+ T-lymphocytes of ducks.Results were as follows:(1) Reaction of T-lymphocytes in PBL to ConA (OD value) of ducks treated with pcDNA-SDIFN-α was higher than that of PBS and pcDNA control groups in 3-84 days.There were highly significant differences between the 1 μg per duck group and the two control groups in 3-84 days (P ≤ 0.01),between the 3 μg per duck group and the two control groups in 3-84 days (P ≤ 0.01,P ≤ 0.05),and between the 6 μg per duck group and the two control groups in 7-49 days (P ≤ 0.01,P ≤ 0.05).The significant difference was also present between the groups of 1,3 and 6 μg per duck in 3-35 days (P ≤ 0.05).However,there was no significant difference between the 3 and 6 μg per duck groups (P ≥ 0.05).The pcDNA control group was higher than PBS control group,but no difference was detected (P ≥ 0.05).(2) Change of the number of CD3+ T-lymphocytes in ducks administered with different doses of pcDNA-SDIFN-α was higher than that of PBS and pcDNA control groups in 7-49 days.The change in the 1 μg per duck group was significantly higher than that in PBS and pcDNA control groups in 14-49 days (P ≤ 0.01).There were significant differences between the 3 μg per

  8. One-dose vaccination associated with attenuated disease severity of adolescent and adult varicella cases in Beijing’s Fengtai District

    Science.gov (United States)

    Zhang, Xue; yu, yuncui; Zhang, Jie; P Kwan, Edwin; Huang, Shengtian; Wang, Zhongzhan; Zhang, Jianjun; Peng, Xiaoxia; Yan, Yuxiang; Zhang, Lin; Luo, Yanxia; Han, Shujing; Han, Xu; Liu, Guangxue; Liu, Fen; Zhao, Jianzhong; He, Yan

    2014-01-01

    Background In recent years, the number of varicella cases in adults has significantly increased in Beijing. However, the effect of the vaccination on varicella-related characteristics among adults has not been studied. Methods and Results: Using data from the Infectious Disease Reporting System and the Immunization Information System, we compared the epidemiology and disease severity in breakthrough and unvaccinated varicella cases in adolescents and adults (≥ 15 year-old) from 2008 to 2011 in Beijing’s Fengtai district, China. The results showed that the age (P = 0.003),contact history (90% vs. 73%, P = 0.019) and outbreak cases (10% vs. 1%, P < 0.0001) were significantly differently distributed between the two groups and that both the incidence of moderate-to-severe cases (26% vs. 45%, P = 0.035, OR = 0.446) and varicella-associated fever (49% vs. 66%, P = 0.068, OR = 0.534) were either significantly lower or trended to be lower in the breakthrough group than in the unvaccinated group. Additionally,vaccine effectiveness against moderate-to-severe cases of varicella was 55.4%. Conclusion: Altogether, these results indicate that vaccination against varicella among adolescents and adults affected the epidemiology and attenuated the disease severity of the cases. The Results from this study will provide useful information for the prevention of varicella in adolescents and adults. PMID:25424949

  9. Immunity to Schistosoma mansoni in guinea-pigs vaccinated with radiation-attenuated cercariae. T-cell activation of macrophages for larval killing

    International Nuclear Information System (INIS)

    This study addresses macrophage activation in guinea-pigs vaccinated with radiation-attenuated cercariae of Schistosom mansoni. Peritoneal exudate macrophages elicited in vaccinated animals by mineral oil injection were activated to kill larval schistosomes in vitro. Killing efficiency is dependent upon the cell:target ratio employed and is enhanced by, but is not strictly dependent on, the presence of specific antibodies. Macrophages co-cultured with parasites release superoxide radicals and hydrogen peroxide, but the use of inhibitors has shown that neither of these reactive oxygen intermediates are the causal agents of cellular cytotoxicity in this system. Oil-elicited macrophages from naive guinea-pigs do not show comparable activation; they can, however, be activated in vitro by incubation with culture supernatant fluids from schistosome antigen-stimulated spleen, or lymph node cells harvested from vaccinated guinea-pigs. Naive macrophages activated in this way kill schistosomula in vitro and release the activation markers IL-l and superoxide anion. The macrophage-activating factor (MAF) present in spleen cell culture supernatant fluids has a MW of 35,000-55,000, but does not have the chemical characteristics of gamma-interferon. (author)

  10. Immunity to Schistosoma mansoni in guinea-pigs vaccinated with radiation-attenuated cercariae. T-cell activation of macrophages for larval killing

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, J.R.; McLaren, D.J.

    1988-02-01

    This study addresses macrophage activation in guinea-pigs vaccinated with radiation-attenuated cercariae of Schistosom mansoni. Peritoneal exudate macrophages elicited in vaccinated animals by mineral oil injection were activated to kill larval schistosomes in vitro. Killing efficiency is dependent upon the cell:target ratio employed and is enhanced by, but is not strictly dependent on, the presence of specific antibodies. Macrophages co-cultured with parasites release superoxide radicals and hydrogen peroxide, but the use of inhibitors has shown that neither of these reactive oxygen intermediates are the causal agents of cellular cytotoxicity in this system. Oil-elicited macrophages from naive guinea-pigs do not show comparable activation; they can, however, be activated in vitro by incubation with culture supernatant fluids from schistosome antigen-stimulated spleen, or lymph node cells harvested from vaccinated guinea-pigs. Naive macrophages activated in this way kill schistosomula in vitro and release the activation markers IL-l and superoxide anion. The macrophage-activating factor (MAF) present in spleen cell culture supernatant fluids has a MW of 35,000-55,000, but does not have the chemical characteristics of gamma-interferon.

  11. Oral infection with the Salmonella enterica serovar Gallinarum 9R attenuated live vaccine as a model to characterise immunity to fowl typhoid in the chicken

    Directory of Open Access Journals (Sweden)

    Beal Richard

    2005-09-01

    Full Text Available Abstract Background Salmonella enterica serovar Gallinarum (S. Gallinarum is the causative agent of fowl typhoid, a severe systemic disease of chickens that results in high mortality amongst infected flocks. Due to its virulence, the immune response to S. Gallinarum is poorly characterised. In this study we have utilised infection by the live attenuated S. Gallinarum 9R vaccine strain in inbred chickens to characterise humoral, cellular and cytokine responses to systemic salmonellosis. Results Infection with 9R results in a mild systemic infection. Bacterial clearance at three weeks post infection coincides with increases in circulating anti-Salmonella antibodies, increased T cell proliferation to Salmonella challenge and increased expression of interferon gamma. These responses peak at four weeks post infection, then decline. Only modest increases of expression of the pro-inflammatory cytokine interleukin-1β were detected early in the infection. Conclusion Infection of chickens with the 9R vaccine strain induces a mild form of systemic salmonellosis. This induces both cellular and humoral immune responses, which peak soon after bacterial clearance. Unlike enteric-associated Salmonella infections the immune response is not prolonged, reflecting the absence of persistence of Salmonella in the gastrointestinal tract. The findings here indicate that the use of the S. Gallinarum 9R vaccine strain is an effective model to study immunity to systemic salmonellosis in the chicken and may be employed in further studies to determine which components of the immune response are needed for protection.

  12. Vaccine independence, local competences and globalisation: lessons from the history of pertussis vaccines.

    Science.gov (United States)

    Blume, Stuart; Zanders, Mariska

    2006-10-01

    In the context of global vaccine politics 'vaccine independence' has been defined as the assumption of financial responsibility for vaccine procurement. This paper suggests 'the possibility of vaccine choice' as an alternative meaning for the term. How far does local competence in vaccine development and production provide that possibility? Coupled to the national vaccination programme, such competence enabled the Netherlands to make use of a polio vaccine (Inactivated Polio Vaccine, or IPV) that it was felt best met national needs even though the rest of the world had switched to the alternative attenuated vaccine (generally known as Oral Polio Vaccine, or OPV); by the 1970s IPV was no longer commercially available. Over the past 20 years major changes in vaccine politics have occurred. Does the earlier conclusion regarding local competence still hold? The more recent example of pertussis (or whooping cough) vaccines, where again controversy surrounds the relative merits of alternative vaccines, permits the question to be posed anew. Results of our analysis from the Netherlands suggest, first, that the pressure to conform has become greater, and second, that the taken-for-granted globalism of today's vaccine system is in need of critical examination. PMID:16764977

  13. Live attenuated Rev-independent Nef¯SIV enhances acquisition of heterologous SIVsmE660 in acutely vaccinated rhesus macaques.

    Directory of Open Access Journals (Sweden)

    Siddappa N Byrareddy

    Full Text Available Rhesus macaques (RMs inoculated with live-attenuated Rev-Independent Nef¯ simian immunodeficiency virus (Rev-Ind Nef¯SIV as adults or neonates controlled viremia to undetectable levels and showed no signs of immunodeficiency over 6-8 years of follow-up. We tested the capacity of this live-attenuated virus to protect RMs against pathogenic, heterologous SIVsmE660 challenges.Three groups of four RM were inoculated with Rev-Ind Nef¯SIV and compared. Group 1 was inoculated 8 years prior and again 15 months before low dose intrarectal challenges with SIVsmE660. Group 2 animals were inoculated with Rev-Ind Nef¯SIV at 15 months and Group 3 at 2 weeks prior to the SIVsmE660 challenges, respectively. Group 4 served as unvaccinated controls. All RMs underwent repeated weekly low-dose intrarectal challenges with SIVsmE660. Surprisingly, all RMs with acute live-attenuated virus infection (Group 3 became superinfected with the challenge virus, in contrast to the two other vaccine groups (Groups 1 and 2 (P=0.006 for each and controls (Group 4 (P=0.022. Gene expression analysis showed significant upregulation of innate immune response-related chemokines and their receptors, most notably CCR5 in Group 3 animals during acute infection with Rev-Ind Nef¯SIV.We conclude that although Rev-Ind Nef¯SIV remained apathogenic, acute replication of the vaccine strain was not protective but associated with increased acquisition of heterologous mucosal SIVsmE660 challenges.

  14. Development of a Murine Mycobacterial Growth Inhibition Assay for Evaluating Vaccines against Mycobacterium tuberculosis▿ †

    OpenAIRE

    Parra, Marcela; Yang, Amy L.; Lim, Jaehyun; Kolibab, Kristopher; Derrick, Steven; Cadieux, Nathalie; Perera, Liyanage P.; Jacobs, William R.; Brennan, Michael; Morris, Sheldon L.

    2009-01-01

    The development and characterization of new tuberculosis (TB) vaccines has been impeded by the lack of reproducible and reliable in vitro assays for measuring vaccine activity. In this study, we developed a murine in vitro mycobacterial growth inhibition assay for evaluating TB vaccines that directly assesses the capacity of immune splenocytes to control the growth of Mycobacterium tuberculosis within infected macrophages. Using this in vitro assay, protective immune responses induced by immu...

  15. Progress on the research and development of inactivated EV71 whole-virus vaccines

    OpenAIRE

    Liang, Zheng-Lun; Mao, Qun-Ying; Wang, Yi-Ping; Zhu, Feng-cai; Li, Jing-Xin; Xin YAO; Gao, Fan; Wu, Xing; Xu, Miao; Wang, Jun-Zhi

    2013-01-01

    The prevalence of diseases caused by EV71 infection has become a serious public health problem in the Western Pacific region. Due to a lack of effective treatment options, controlling EV71 epidemics has mainly focused on the research and development (R&D) of EV71 vaccines. Thus far, five organizations have completed pre-clinical studies focused on the development of inactivated EV71 whole-virus vaccines, including vaccine strain screening, process optimization, safety and immunogenicity evalu...

  16. Malaria vaccine research and development: the role of the WHO MALVAC committee

    OpenAIRE

    Targett, GA; Moorthy, VS; Brown, GV

    2013-01-01

    The WHO Malaria Vaccine Advisory Committee (MALVAC) provides advice to WHO on strategic priorities, activities and technical issues related to global efforts to develop vaccines against malaria. MALVAC convened a series of meetings to obtain expert, impartial consensus views on the priorities and best practice for vaccine-related research and development strategies. The technical areas covered during these consultations included: guidance on clinical trial design for candidate sporozoite and ...

  17. Current perspective in tuberculosis vaccine development for high TB endemic regions.

    Science.gov (United States)

    Husain, Aliabbas A; Daginawala, Hatim F; Singh, Lokendra; Kashyap, Rajpal S

    2016-05-01

    Tuberculosis (TB) continues to be a global epidemic, despite of the availability of Bacillus Calmette Guerin (BCG) vaccine for more than six decades. In an effort to eradicate TB, vaccinologist around the world have made considerable efforts to develop improved vaccine candidates, based on the understanding of BCG failure in developing world and immune response thought to be protective against TB. The present review represents a current perspective on TB vaccination research, including additional research strategies needed for increasing the efficacy of BCG, and for the development of new effective vaccines for high TB endemic regions. PMID:27156631

  18. Development of a vaccine strategy against human and bovine schistosomiasis: background and update

    Directory of Open Access Journals (Sweden)

    André Capron

    1995-04-01

    . Immunization with the corresponding synthetic peptides was followed by a decrease of 70% of parasite fecundity and egg viability. As a preliminary step towards phase I human trials, vaccination experiments have been performed in cattle, a natural model for Schistosoma bovis. Vaccination of calves with the S. bovis GST has led to a reduction of ever 80% of egg output and tissue egg count. Significant levels of protection were also observed in goats after immunization with the recombinant S. bovis GST. Increasing evidence of the participation of IgA antibodies in protective immunity has prompted us toward the development of mucosal immunization. Preliminary results indicate that significant levels of protection can be achieved following oral immunization with live attenuated vectors or liposomes. These studies seem to represent a promising approach towards the future development of a vaccine strategy against one of major human parasitic diseases.

  19. Parasite vaccines--a reality?

    Science.gov (United States)

    Dalton, J P; Mulcahy, G

    2001-07-12

    Over the last decade, the anti-parasitics market has been the fastest growing sector of the overall $18 billion animal health market. While drugs for the treatment of parasites of livestock still dominate this sector and will continue to be developed or re-formulated, because of consumer demands for chemical-free food and of concerns regarding the environment and animal welfare there is a growing interest in the development of safe and effective vaccines. There is also a call for vaccines in the lucrative $3 billion-plus companion animal market. These demands for vaccines will add a greater impetus to an area that has seen tremendous success in the last 15 years. A number of anti-parasite vaccines have been developed, e.g. the recombinant 45w and EG95 oncosphere proteins against Taenia ovis and Echinococcus granulosis, respectively, and the Bm86 vaccine against Boophilus microplus. In addition, the cathepsin L vaccines against the liver fluke, Fasciola hepatica, and the H11 vaccine against Haemonchus contortus are progressing well. There are also many additional vaccine candidates for H. contortus and for other nematodes such as Ostertagia and Trichostrongylus spp. that may ultimately lead to broad-spectrum gastrointestinal worm vaccines. Live or attenuated-live vaccines are available for the control of avian coccidiosis, toxplasmosis in sheep and anaplasmosis in cattle, although molecular vaccines against protozoans are still proving elusive. The wealth of information in genomics, proteomics and immunology that has been forthcoming together will new methods of vaccine production and delivery should see many new vaccines reach the marketplace in the near future. PMID:11516584

  20. Is an HIV vaccine possible?

    Directory of Open Access Journals (Sweden)

    Nancy A. Wilson

    2009-08-01

    Full Text Available The road to the discovery of a vaccine for HIV has been arduous and will continue to be difficult over the ensuing twenty years. Most vaccines are developed by inducing neutralizing antibodies against the target pathogen or by using attenuated strains of the particular pathogen to engender a variety of protective immune responses. Unfortunately, simple methods of generating anti-HIV antibodies have already failed in a phase III clinical trial. While attenuated SIV variants work well against homologous challenges in non-human primates, the potential for reversion to a more pathogenic virus and recombination with challenge viruses will preclude the use of attenuated HIV in the field. It has been exceedingly frustrating to vaccinate for HIV-specific neutralizing antibodies given the enormous diversity of the Envelope (Env glycoprotein and its well-developed glycan shield. However, there are several antibodies that will neutralize many different strains of HIV and inducing these types of antibodies in vaccinees remains the goal of a vigorous effort to develop a vaccine for HIV based on neutralizing antibodies. Given the difficulty in generating broadly reactive neutralizing antibodies, the HIV vaccine field has turned its attention to inducing T cell responses against the virus using a variety of vectors. Unfortunately, the results from Merck's phase IIb STEP trial proved to be disappointing. Vaccinees received Adenovirus type 5 (Ad5 expressing Gag, Pol, and Nef of HIV. This vaccine regimen failed to either prevent infection or reduce the level of HIV replication after challenge. These results mirrored those in non-human primate testing of Ad5 using rigorous SIV challenge models. This review will focus on recent developments in HIV vaccine development. We will deal largely with attempts to develop a T cell-based vaccine using the non-human primate SIV challenge model.

  1. Evaluation of Efficacy of Stabilizers on the Thermostability of Live Attenuated Thermo-adapted Peste des petits ruminants Vaccines

    Institute of Scientific and Technical Information of China (English)

    Thachamvally Riyesh; Vinayagamurthy Balamurugan; Amab Sen; Veerakyathappa Bhanuprakash; Gnanavel Venkatesan; Vinita Yadav; Raj Kumar Singh

    2011-01-01

    In this study,thermo-adapted(Ta)PPR vaccines were assessed for their stability at 25,37,40,42 and 45℃ in lyophilized form using two extrinsic stabilizers(lactalbumin hydrolysate-sucrose(LS)and stabilizer E)and in reconstituted form with the diluents(1 mol/L MgS04 or 0.85% NaCl). The lyophilized vaccines showed an expiry period of 24-26 days at 25℃,7-8 days at 37℃ and 3-4 days at 40℃. LS stabilizer was superior at 42℃ with a shelf-life of 44 h,whereas in stabilizer E,a 40 h shelf-life with a comparable half-life was observed. At 45℃,the half-life in stabilizer E was better than LS and lasted for 1 day. Furthermore,the reconstituted vaccine maintained the titre for 48 h both at 4℃ and 25℃ and for 24-30 h at 37℃. As both the stabilizers performed equally well with regard to shelf-life and half-life,the present study suggests LS as stabilizer as a choice for lyophilization with 0.85% NaCI diluent,because it has better performance at higher temperature. These Ta vaccines can be used as alternatives to existing vaccines for the control of the disease in tropical countries as they are effective in avoiding vaccination failure due to the breakdown in cold-chain maintenance,as this vaccine is considerably more stable at ambient temperatures.

  2. High Throughput T Epitope Mapping and Vaccine Development

    Directory of Open Access Journals (Sweden)

    Giuseppina Li Pira

    2010-01-01

    Full Text Available Mapping of antigenic peptide sequences from proteins of relevant pathogens recognized by T helper (Th and by cytolytic T lymphocytes (CTL is crucial for vaccine development. In fact, mapping of T-cell epitopes provides useful information for the design of peptide-based vaccines and of peptide libraries to monitor specific cellular immunity in protected individuals, patients and vaccinees. Nevertheless, epitope mapping is a challenging task. In fact, large panels of overlapping peptides need to be tested with lymphocytes to identify the sequences that induce a T-cell response. Since numerous peptide panels from antigenic proteins are to be screened, lymphocytes available from human subjects are a limiting factor. To overcome this limitation, high throughput (HTP approaches based on miniaturization and automation of T-cell assays are needed. Here we consider the most recent applications of the HTP approach to T epitope mapping. The alternative or complementary use of in silico prediction and experimental epitope definition is discussed in the context of the recent literature. The currently used methods are described with special reference to the possibility of applying the HTP concept to make epitope mapping an easier procedure in terms of time, workload, reagents, cells and overall cost.

  3. Need for a safe vaccine against respiratory syncytial virus infection

    Directory of Open Access Journals (Sweden)

    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.

  4. From the Bench to the Pharmacy: Protecting Innovation During Vaccine Development and Commercialization.

    Science.gov (United States)

    Krol, Adam C; Abu-Shaar, Muna; Brady, Paul

    2016-01-01

    Patentable inventions may be made during the development of a vaccine, and patents on such inventions can help to protect the vaccine from competition. This chapter introduces several patent law concepts, including patent eligible subject matter, written description, enablement, novelty, and nonobviousness, by following a hypothetical vaccine development timeline that begins with the discovery of a previously unknown virus and ends with the commercial launch of a vaccine against the virus. Regulatory exclusivity, freedom to operate, and lifecycle management considerations are also discussed. PMID:27076339

  5. EXPERIMENTAL MEASLES VACCINES: A RESEARCH TOOL IN VACCINATION EVENTS

    OpenAIRE

    V. A. Liashenko

    2014-01-01

    Abstract. The review article considers different variants of measles vaccine that may be classified into two groups, i.e., vaccines that do not contain viable measles virus, and attenuated measles vaccines which could be employed in unusual manner.The first group includes DNA-vaccines, recombinant vaccine strains encoding synthesis of measles hemagglutinin and fusion protein, as well as peptide vaccines containing molecular fragments of these proteins. The mentioned variants of vaccines were ...

  6. Development, theoretical framework, and evaluation of a parent and teacher-delivered intervention on adolescent vaccination.

    Science.gov (United States)

    Gargano, Lisa M; Herbert, Natasha L; Painter, Julia E; Sales, Jessica M; Vogt, Tara M; Morfaw, Christopher; Jones, LaDawna M; Murray, Dennis; DiClemente, Ralph J; Hughes, James M

    2014-07-01

    The Advisory Committee on Immunization Practices recommended immunization schedule for adolescents includes three vaccines (tetanus, diphtheria, and acellular pertussis [Tdap]; human papillomavirus [HPV] vaccine; and meningococcal conjugate vaccine [MCV4]) and an annual influenza vaccination. Given the increasing number of recommended vaccines for adolescents and health and economic costs associated with nonvaccination, it is imperative that effective strategies for increasing vaccination rates among adolescents are developed. This article describes the development, theoretical framework, and initial first-year evaluation of an intervention designed to promote vaccine acceptance among a middle and high school-based sample of adolescents and their parents in eastern Georgia. Adolescents, parents, and teachers were active participants in the development of the intervention. The intervention, which consisted of a brochure for parents and a teacher-delivered curriculum for adolescents, was guided by constructs from the health belief model and theory of reasoned action. Evaluation results indicated that our intervention development methods were successful in creating a brochure that met cultural relevance and the literacy needs of parents. We also demonstrated an increase in student knowledge of and positive attitudes toward vaccines. To our knowledge, this study is the first to extensively engage middle and high school students, parents, and teachers in the design and implementation of key theory-based educational components of a school-based, teacher-delivered adolescent vaccination intervention. PMID:24440920

  7. Research Advances in Identiifcation of Attenuated Brucella Vaccines%布鲁氏菌弱毒疫苗鉴别技术研究进展

    Institute of Scientific and Technical Information of China (English)

    南文龙; 谭鹏飞; 彭大新; 陈义平

    2014-01-01

    布鲁氏菌病是由布鲁氏菌引起的一种重要的人畜共患传染病,不仅给畜牧业造成严重的经济损失,并威胁人类健康。弱毒疫苗免疫是防控布病的重要手段,但弱毒疫苗的使用往往对布病的诊断和监测造成干扰。各国学者利用细菌学、免疫学、分子生物学等技术手段,建立了病原分离鉴定、补体结合试验、利凡诺尔试验、酶联免疫吸附试验、荧光偏振实验、限制性片段长度多态性、PCR、real-time PCR等多种布鲁氏菌弱毒疫苗鉴别检测方法。研究表明,ELISA和FPT以其高通量以及操作方便的优势,在布鲁氏菌弱毒疫苗与野生菌株感染的血清学鉴别诊断方面前景良好;分子生物学特别是PCR、real-time PCR方法目前仍广泛用于布鲁氏菌纯培养物的鉴定。%Brucellosis is a crucial zoonosis caused by Brucella. It is responsible for substantial economic losses and poses a threat to human health as well. Immunization with attenuated vaccines has proved to be an effective method for its prevention;however,it may interfere with its diagnosis. Using bacteriology,immunology and molecular biology techniques,many identiifcation assays for attenuated Brucella vaccines were established,such as pathogen isolation and identiifcation,complement ifxation test,rivanol test,ELISA,fluorescence polarization test,restriction frag-ment length polymorphism,PCR,real-time PCR and so on. These studies indicated that with the advantages of high throughput and easy operation,ELISA and FTP have good prospects in serological identiifcation of attenuated Brucella vaccines. Moreover,molecular biological methods,especially PCR and real-time PCR,are still widely used for iden-tiifcation of the pure cultures.

  8. The introduction of new vaccines into developing countries. IV: Global Access Strategies.

    Science.gov (United States)

    Mahoney, Richard T; Krattiger, Anatole; Clemens, John D; Curtiss, Roy

    2007-05-16

    This paper offers a framework for managing a comprehensive Global Access Strategy for new vaccines in developing countries. It is aimed at strengthening the ability of public-sector entities to reach their goals. The Bill and Melinda Gates Foundation and The Rockefeller Foundation have been leaders in stimulating the creation of new organizations - public/private product development partnerships (PDPs) - that seek to accelerate vaccine development and distribution to meet the health needs of the world's poor. Case studies of two of these PDPs - the Salmonella Anti-pneumococcal Vaccine Program and the Pediatric Dengue Vaccine Initiative - examine development of such strategies. Relying on the application of innovation theory, the strategy leads to the identification of six Components of Innovation which cover all aspects of the vaccine innovation process. Appropriately modified, the proposed framework can be applied to the development and introduction of other products in developing countries including drugs, and nutritional and agricultural products. PMID:17363119

  9. Clinical trials for vaccine development in registry of Korea Food and Drug Administration

    OpenAIRE

    Kang, Seog-Youn

    2013-01-01

    Based on the action plan "Ensuring a stable supply of National Immunization Program vaccines and sovereignty of biopharmaceutical products," Korea Food and Drug Administration (KFDA) has made efforts to develop vaccines in the context of self reliance and to protect public health. Along with the recognized infrastructures for clinical trials, clinical trials for vaccines have also gradually been conducted at multinational sites as well as at local sites. KFDA will support to expand six to ele...

  10. Clinical Development of a Cytomegalovirus DNA Vaccine: From Product Concept to Pivotal Phase 3 Trial

    OpenAIRE

    Michele Gerber; Alain P. Rolland; Chaplin, Jennifer A.; Mary K. Wloch; Smith, Larry R

    2013-01-01

    2013 marks a milestone year for plasmid DNA vaccine development as a first-in-class cytomegalovirus (CMV) DNA vaccine enters pivotal phase 3 testing. This vaccine consists of two plasmids expressing CMV antigens glycoprotein B (gB) and phosphoprotein 65 (pp65) formulated with a CRL1005 poloxamer and benzalkonium chloride (BAK) delivery system designed to enhance plasmid expression. The vaccine’s planned initial indication under investigation is for prevention of CMV reactivation in CMV-seropo...

  11. Whole organism blood stage vaccines against malaria.

    Science.gov (United States)

    Stanisic, Danielle I; Good, Michael F

    2015-12-22

    Despite a century of research focused on the development and implementation of effective control strategies, infection with the malaria parasite continues to result in significant morbidity and mortality worldwide. An effective malaria vaccine is considered by many to be the definitive solution. Yet, after decades of research, we are still without a vaccine that is capable of inducing robust, long lasting protection in naturally exposed individuals. Extensive sub-unit vaccine development focused on the blood stage of the malaria parasite has thus far yielded disappointing results. There is now a renewed focus on whole parasite vaccine strategies, particularly as they may overcome some of the inherent weaknesses deemed to be associated with the sub-unit approach. This review discusses the whole parasite vaccine strategy focusing on the blood stage of the malaria parasite, with an emphasis on recent advances and challenges in the development of killed and live attenuated vaccines. PMID:26428451

  12. Current challenges in the development of vaccines for pneumonic plague

    OpenAIRE

    Smiley, Stephen T.

    2008-01-01

    Inhalation of Yersinia pestis bacilli causes pneumonic plague, a rapidly progressing and exceptionally virulent disease. Extensively antibiotic-resistant Y. pestis strains exist and we currently lack a safe and effective pneumonic plague vaccine. These facts raise concern that Y. pestis may be exploited as a bioweapon. Here, I review the history and status of plague vaccine research and advocate that pneumonic plague vaccines should strive to prime both humoral and cellular immunity.

  13. 76 FR 49776 - The Development and Evaluation of Next-Generation Smallpox Vaccines; Public Workshop

    Science.gov (United States)

    2011-08-11

    ... HUMAN SERVICES Food and Drug Administration The Development and Evaluation of Next-Generation Smallpox... workshop entitled ``The Development and Evaluation of Next-Generation Smallpox Vaccines.'' The purpose of... evaluation of next-generation smallpox vaccines. The public workshop will include presentations on the...

  14. The second Geneva Consensus: Recommendations for novel live TB vaccines.

    Science.gov (United States)

    Walker, K B; Brennan, M J; Ho, M M; Eskola, J; Thiry, G; Sadoff, J; Dobbelaer, R; Grode, L; Liu, M A; Fruth, U; Lambert, P H

    2010-03-01

    Infection with Mycobacterium tuberculosis continues to be a major public health burden in most developing parts of the world and efforts to develop effective strategies for containing the disease remain a priority. It has long been evident that effective mass vaccination programmes are a cost effective and efficient approach to controlling communicable diseases in a public health setting and tuberculosis (TB) continues to be a major target. One approach with increasing acceptance is based upon on live mycobacterial vaccines, either as recombinant BCG or rationally attenuated M. tuberculosis, thus generating a new live TB vaccine. The Geneva Consensus published in March 2005 set out the opinion on priorities and requirements for developing live mycobacterial vaccines for Phase I trials. In the intervening period much progress has been made in both preclinical and clinical development of new TB vaccines and has provided the impetus for organising the second Geneva Consensus (held at WHO headquarters, April 2009) to discuss issues, including: i. Explore the regulatory requirements for live TB vaccines to enter Phase I trials, in particular those based on attenuated M. tuberculosis. Particular attention was paid to the characterisation and safety package likely to be required, including issues of attenuation, the presence of antibiotic resistance markers in live vaccines and the nature of any attenuated vaccine phenotype. ii. To identify the general criteria for further clinical development from Phase I through to Phase III. iii. Obtain a perspective of the regulatory landscape of developing countries where Phase II and III trials are to be held. iv. Review manufacturing considerations for live TB vaccines and relevance of the WHO and European Pharmacopeia guidelines and requirements for BCG vaccine. v. Consider requirements and associated issues related to the use of these new vaccines within an existing BCG vaccination programme. PMID:20074686

  15. Mechanisms of immunity in hydatid disease: implications for vaccine development.

    Science.gov (United States)

    Zhang, Wenbao; Ross, Allen G; McManus, Donald P

    2008-11-15

    The Echinococcus organisms, the cause of echinococcosis (hydatid disease), are parasitic helminths with life cycles involving a carnivorous definitive host (usually dog or fox) and an intermediate host (human, ungulate, or rodent). They are complex multicellular pathogens that, despite being under constant barrage by the immune system, are able to modulate antiparasite immune responses and persist and flourish in their mammalian hosts. Understanding how the immune system deals with these parasites is a major challenge. Recent application of modern molecular and immunological approaches has revealed insights on the nature of immune responses generated during the course of hydatid infection, although many aspects of the Echinococcus-host interplay remain unexplored. This review summarizes current understanding of the immunology of echinococcosis, indicates areas where information is lacking, and shows how knowledge of host protective immunity has been translated into the design and development of anti-Echinococcus vaccines for application in intermediate hosts. PMID:18981082

  16. Hepatitis Vaccines

    OpenAIRE

    Ogholikhan, Sina; Schwarz, Kathleen B

    2016-01-01

    Viral hepatitis is a serious health problem all over the world. However, the reduction of the morbidity and mortality due to vaccinations against hepatitis A and hepatitis B has been a major component in the overall reduction in vaccine preventable diseases. We will discuss the epidemiology, vaccine development, and post-vaccination effects of the hepatitis A and B virus. In addition, we discuss attempts to provide hepatitis D vaccine for the 350 million individuals infected with hepatitis B ...

  17. Comparison of the efficacy of autogenous inactivated Porcine Reproductive and Respiratory Syndrome Virus (PRRSV vaccines with that of commercial vaccines against homologous and heterologous challenges

    Directory of Open Access Journals (Sweden)

    Geldhof Marc F

    2012-10-01

    Full Text Available Abstract Background The porcine reproductive and respiratory syndrome virus (PRRSV is a rapidly evolving pathogen of swine. At present, there is a high demand for safe and more effective vaccines that can be adapted regularly to emerging virus variants. A recent study showed that, by the use of a controlled inactivation procedure, an experimental BEI-inactivated PRRSV vaccine can be developed that offers partial protection against homologous challenge with the prototype strain LV. At present, it is however not known if this vaccine can be adapted to currently circulating virus variants. In this study, two recent PRRSV field isolates (07 V063 and 08 V194 were used for BEI-inactivated vaccine production. The main objective of this study was to assess the efficacy of these experimental BEI-inactivated vaccines against homologous and heterologous challenge and to compare it with an experimental LV-based BEI-inactivated vaccine and commercial inactivated and attenuated vaccines. In addition, the induction of challenge virus-specific (neutralizing antibodies by the different vaccines was assessed. Results In a first experiment (challenge with 07 V063, vaccination with the experimental homologous (07 V063 inactivated vaccine shortened the viremic phase upon challenge with approximately 2 weeks compared to the mock-vaccinated control group. Vaccination with the commercial attenuated vaccines reduced the duration of viremia with approximately one week compared to the mock-vaccinated control group. In contrast, the experimental heterologous (LV inactivated vaccine and the commercial inactivated vaccine did not influence viremia. Interestingly, both the homologous and the heterologous experimental inactivated vaccine induced 07 V063-specific neutralizing antibodies upon vaccination, while the commercial inactivated and attenuated vaccines failed to do so. In the second experiment (challenge with 08 V194, use of the experimental homologous (08 V194

  18. Adjuvant-enhanced CD4 T Cell Responses are Critical to Durable Vaccine Immunity

    OpenAIRE

    Martins, Karen A O; Christopher L Cooper; Stronsky, Sabrina M.; Sarah L.W. Norris; Steven A Kwilas; Jesse T. Steffens; Benko, Jacqueline G.; van Tongeren, Sean A.; Sina Bavari

    2016-01-01

    Protein-based vaccines offer a safer alternative to live-attenuated or inactivated vaccines but have limited immunogenicity. The identification of adjuvants that augment immunogenicity, specifically in a manner that is durable and antigen-specific, is therefore critical for advanced development. In this study, we use the filovirus virus-like particle (VLP) as a model protein-based vaccine in order to evaluate the impact of four candidate vaccine adjuvants on enhancing long term protection fro...

  19. Development of Vaccines against Influenza A Virus (H5N1

    Directory of Open Access Journals (Sweden)

    Yhu-Chering Huang

    2007-08-01

    Full Text Available Three influenza pandemics took place during the 20thcentury, including the 1918 pandemic, which killed an estimated50 million people. We are facing the threat of anotherpandemic, which may be caused by an A/H5N1 influenzavirus. These viruses have expanded their territory from Asiato the Middle East, Africa and Europe and have caused morethan 190 human deaths up to the present. Vaccines in responseto this pandemic threat are currently under development.Reverse-genetics-based inactivated whole-virion vaccines andadjuvanted split-virion vaccines are undergoing clinical trialsand are among possible candidates to be approved as H5N1vaccines for human beings. Problems, including low immunogenicityin the generally naive human population, a lack ofdata on these vaccines in relation to immunocompromisedpatients, young children and the elderly and the currently limitedglobal capacity to manufacture influenza vaccines, all need to be resolved. Several innovativeapproaches, such as the use of novel adjuvants, an antigen-sparing policy and the useof adenoviral-vector-based or DNA vaccines, are being used to develop more efficient vaccines.Every effort should be made to shorten the gap that remains and improve greatlyinfluenza pandemic vaccine access.

  20. Development of vaccines against influenza A virus (H5N1).

    Science.gov (United States)

    Li, Wen-Chen; Huang, Yhu-Chering

    2007-01-01

    Three influenza pandemics took place during the 20th century, including the 1918 pandemic, which killed an estimated 50 million people. We are facing the threat of another pandemic, which may be caused by an A/H5N1 influenza virus. These viruses have expanded their territory from Asia to the Middle East, Africa and Europe and have caused more than 190 human deaths up to the present. Vaccines in response to this pandemic threat are currently under development. Reverse-genetics-based inactivated whole-virion vaccines and adjuvanted split-virion vaccines are undergoing clinical trials and are among possible candidates to be approved as H5N1 vaccines for human beings. Problems, including low immunogenicity in the generally naive human population, a lack of data on these vaccines in relation to immunocompromised Dr. Yhu-Chering Huang patients, young children and the elderly and the currently limited global capacity to manufacture influenza vaccines, all need to be resolved. Several innovative approaches, such as the use of novel adjuvants, an antigen-sparing policy and the use of adenoviral-vector-based or DNA vaccines, are being used to develop more efficient vaccines. Every effort should be made to shorten the gap that remains and improve greatly influenza pandemic vaccine access. PMID:17939259