scholarly journals Development of Japanese Encephalitis Attenuated Live Vaccine Virus SA14-14-2 and its Charcteristics

Encephalitis ◽  
10.5772/52980 ◽  
2013 ◽  
Author(s):  
Yongxin Yu
Keyword(s):  
Japanese Encephalitis ◽  
Vaccine Virus ◽  
Live Vaccine

scholarly journals Development and characterization of the replicon system of Japanese encephalitis live vaccine virus SA14-14-2

2013 ◽  
Vol 10 (1) ◽  
pp. 64 ◽  
Author(s):  
Shi-Hua Li ◽  
Xiao-Feng Li ◽  
Hui Zhao ◽  
Yong-Qiang Deng ◽  
Xue-Dong Yu ◽  
...  
Keyword(s):  
Japanese Encephalitis ◽  
Vaccine Virus ◽  
Live Vaccine

scholarly journals A single nucleotide mutation in NS2A of Japanese encephalitis-live vaccine virus (SA14-14-2) ablates NS1’ formation and contributes to attenuation

2012 ◽  
Vol 93 (9) ◽  
pp. 1959-1964 ◽  
Author(s):  
Qing Ye ◽  
Xiao-Feng Li ◽  
Hui Zhao ◽  
Shi-Hua Li ◽  
Yong-Qiang Deng ◽  
...  
Keyword(s):  
Japanese Encephalitis ◽  
Structure Prediction ◽  
Secondary Structure Prediction ◽  
Vaccine Virus ◽  
Live Vaccine ◽  
Asia Pacific ◽  
Silent Mutation ◽  
Coding Region ◽  
Nucleotide Mutation

Japanese encephalitis (JE) remains the leading cause of viral encephalitis in the Asia-Pacific region, and the live vaccine SA14-14-2 is currently recommended by WHO and widely used in Asian countries with a good safety and efficacy profile. In this study, we demonstrated that SA14-14-2 failed to produce NS1’, the larger NS1-related protein, compared with its parental strain SA14 in various cells. Sequence analysis and secondary structure prediction identified a single silent mutation G66A in the NS2A-coding region of SA14-14-2 destabilized the conserved pseudoknot structure, which was associated with a −1 ribosomal frame shift event. Using reverse genetic technology and animal study, we provided solid evidence that this single silent mutation G66A in the NS2A gene abolished the production of NS1’ in vitro and reduced neurovirulence and neuroinvasiveness in mice. These findings provide critical information in understanding the molecular mechanism of JE vaccine attenuation and is critical for JE vaccine quality control.

scholarly journals Molecular characterization of attenuated Japanese encephalitis live vaccine strain ML-17☆

Vaccine ◽  
2006 ◽  
Vol 24 (4) ◽  
pp. 402-411 ◽  
Author(s):  
Paresh Sumatilal Shah ◽  
Mariko Tanaka ◽  
Afjal Hossain Khan ◽  
Edward Gitau Matumbi Mathenge ◽  
Isao Fuke ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Vaccine Strain ◽  
Japanese Encephalitis ◽  
Live Vaccine ◽  
Live Vaccine Strain

scholarly journals In vitro and in vivo characterization of chimeric duck Tembusu virus based on Japanese encephalitis live vaccine strain SA14-14-2

2016 ◽  
Vol 97 (7) ◽  
pp. 1551-1556 ◽  
Author(s):  
Hong-Jiang Wang ◽  
Long Liu ◽  
Xiao-Feng Li ◽  
Qing Ye ◽  
Yong-Qiang Deng ◽  
...  
Keyword(s):  
Vaccine Strain ◽  
Japanese Encephalitis ◽  
Live Vaccine ◽  
Live Vaccine Strain ◽  
Duck Tembusu Virus ◽  
Tembusu Virus ◽  
In Vivo Characterization

scholarly journals Genetic Determinants of Japanese Encephalitis Virus Vaccine Strain SA14-14-2 That Govern Attenuation of Virulence in Mice

2015 ◽  
Vol 89 (12) ◽  
pp. 6328-6337 ◽  
Author(s):  
Gregory D. Gromowski ◽  
Cai-Yen Firestone ◽  
Stephen S. Whitehead
Keyword(s):  
Tissue Culture ◽  
Amino Acid ◽  
Japanese Encephalitis Virus ◽  
Vaccine Strain ◽  
Japanese Encephalitis ◽  
Second Generation ◽  
Virus Genome ◽  
Vaccine Virus ◽  
Wild Type ◽  
Virulence Attenuation

ABSTRACTThe safety and efficacy of the live-attenuated Japanese encephalitis virus (JEV) SA14-14-2 vaccine are attributed to mutations that accumulated in the viral genome during its derivation. However, little is known about the contribution that is made by most of these mutations to virulence attenuation and vaccine immunogenicity. Here, we generated recombinant JEV (rJEV) strains containing JEV SA14-14-2 vaccine-specific mutations that are located in the untranslated regions (UTRs) and seven protein genes or are introduced from PCR-amplified regions of the JEV SA14-14-2 genome. The resulting mutant viruses were evaluated in tissue culture and in mice. The authentic JEV SA14-14-2 (E) protein, with amino acid substitutions L107F, E138K, I176V, T177A, E244G, Q264H, K279M, A315V, S366A, and K439R relative to the wild-type rJEV clone, was essential and sufficient for complete attenuation of neurovirulence. Individually, the nucleotide substitution T39A in the 5′ UTR (5′-UTR-T39A), the capsid (C) protein amino acid substitution L66S (C-L66S), and the complete NS1/2A genome region containing 10 mutations each significantly reduced virus neuroinvasion but not neurovirulence. The levels of peripheral virulence attenuation imposed by the 5′-UTR-T39A and C-L66S mutations, individually, were somewhat mitigated in combination with other vaccine strain-specific mutations, which might be compensatory, and together did not affect immunogenicity. However, a marked reduction in immunogenicity was observed with the addition of the NS1/2A and NS5 vaccine virus genome regions. These results suggest that a second-generation recombinant vaccine can be rationally engineered to maximize levels of immunogenicity without compromising safety.IMPORTANCEThe live-attenuated JEV SA14-14-2 vaccine has been vital for controlling the incidence of disease caused by JEV, particularly in rural areas of Asia where it is endemic. The vaccine was developed >25 years ago by passaging wild-type JEV strain SA14 in tissue cultures and rodents, with intermittent tissue culture plaque purifications, to produce a virus clone that had adequate levels of attenuation and immunogenicity. The vaccine and parent virus sequences were later compared, and mutations were identified throughout the vaccine virus genome, but their contributions to attenuation were never fully elucidated. Here, using reverse genetics, we comprehensively defined the impact of JEV SA14-14-2 mutations on attenuation of virulence and immunogenicity in mice. These results are relevant for quality control of new lots of the current live-attenuated vaccine and provide insight for the rational design of second-generation, live-attenuated, recombinant JEV vaccine candidates.

scholarly journals Reduction of neutralization antibody against heterologous circulating strains in adults immunized with Japanese encephalitis live vaccine

2014 ◽  
Vol 10 (9) ◽  
pp. 2704-2705 ◽  
Author(s):  
Qing Ye ◽  
Xiao-Feng Li ◽  
Hui Zhao ◽  
Yong-Qiang Deng ◽  
Yan-Peng Xu ◽  
...  
Keyword(s):  
Japanese Encephalitis ◽  
Live Vaccine

Antibody reaction in immunologically naïve replacement gilts vaccinated with an attenuated PRRSV live vaccine

2014 ◽  
Vol 42 (02) ◽  
pp. 95-99 ◽  
Author(s):  
A. Düngelhoef ◽  
S. Lösken ◽  
E. grosse Beilage
Keyword(s):  
Infectious Diseases ◽  
Cost Effective ◽  
Vaccine Virus ◽  
Live Vaccine ◽  
Field Conditions ◽  
Rt Pcr ◽  
Serum Samples ◽  
Serological Reaction ◽  
Blood Samples ◽  
Antibody Reaction

Summary Objective: Serological testing of blood samples is commonly known as an approved method to diagnose infectious diseases. Likewise it is used for monitoring infectious diseases as it is fast and cost-effective. Nevertheless interpretation of results can be difficult, especially when the samples were taken from animals, which received a vaccination prior to the serological examination. This is mainly due to the fact, that not every vaccination induces a measurable antibody reaction. In this recent case gilts were vaccinated with an attenuated live vaccine and the serum samples were negative in the ELISA. The question aroused which serological reaction to a vaccine is expected under field conditions. Material and methods: In order to clarify this question a group of 28 gilts negative for porcine reproductive and respiratory syndrome (PRRS) virus (from a verifiable PRRSV-negative stock) were vaccinated with an attenuated PRRSV vaccine and blood samples were taken on days 0, 2, 4, 8 and 15 post vaccinationem (p. vacc). To provide a reliable means of diagnosis the samples were tested with an antibody ELISA and RT-PCR. Results: A replication of the vaccine virus was demonstrated via RT-PCR in 100% of the animals 4 days p. vacc. The first samples classified positive in the ELISA were detected 8 days p. vacc. On day 15 p. vacc. a positive serological result was obtained for all animals. Conclusion: The vaccination with an attenuated PRRSV vaccine provides a pronounced antibody reaction under field conditions. In case of a negative serological reaction in recently vaccinated pigs all steps from the manufacturing process through to the implementation of the vaccine have to be critically evaluated. Likewise correct laboratory studies and the assessment of diagnostic results need to be scrutinized.

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