Low Protective Efficacy of the Current Japanese Encephalitis Vaccine against the Emerging Genotype 5 Japanese Encephalitis Virus----中国科学院微生物研究所

科研成果

论文题目:	Low Protective Efficacy of the Current Japanese Encephalitis Vaccine against the Emerging Genotype 5 Japanese Encephalitis Virus
作者:	Cao Lei, Fu Shihong , Gao Xiaoyan , Li Minghua , Cui Shiheng, Li Xiaolong , Cao Yuxi, Lei Wenwen, Lu Zhi , He Ying , Wang Huanyu , Yan Jinghua , Gao George Fu, and Liang Guodong.
联系作者:
刊物名称:	Plos Neglected Tropical Diseases
期:
卷:	10
页:
年份:	2016
影响因子:	4.478
论文下载:	http://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0004686
摘要:	Background The current Japanese encephalitis (JE) vaccine derived from G3 JE virus (JEV) can induce protective immunity against G1-G4 JEV genotypes. However, protective efficacy against the emerging G5 genotype has not been reported. Methods/Principal Findings Using in vitro and in vivo tests, biological phenotype and cross-immunoreactions were compared between G3 JEV and G5 JEV (wild strains). The PRNT90 method was used to detect neutralizing antibodies against different genotypes of JEV in JE vaccine-immunized subjects and JE patients. In JE vaccine-immunized mice, the lethal challenge protection rates against G3 and G5 JEV wild strains were 100% and 50%, respectively. The seroconversion rates (SCRs) of virus antibodies against G3 and G5 JEV among vaccinated healthy subjects were 100% and 35%, respectively. All clinically identified JE patients showed high levels of G3 JEV neutralizing antibodies (>= 1:10-1280) with positive serum geometric mean titers (GMTs) of 43.2, while for G5 JEV, neutralizing antibody conversion rates were only 64% with positive serum GMTs of 11.14. Moreover, the positive rate of JEV neutralizing antibodies against G5 JEV in pediatric patients was lower than in adults. Conclusions/Significance Low levels of neutralizing/protective antibodies induced by the current JE vaccine, based on the G3 genotype, were observed against the emerging G5 JEV genotype. Our results demonstrate the need for more detailed studies to reevaluate whether or not the apparent emergence of G5 JEV can be attributed to failure of the current vaccine to induce appropriate immune protectivity against this genotype of JEV.