Immunity and clinical efficacy of an inactivated enterovirus 71 vaccine in healthy Chinese children: a report of further observations

作者：Longding Liu, Zhaojun Mo, Zhenglun Liang, Ying Zhang, Rongcheng Li, Kien Chai Ong, Kum Thong Wong, Erxia Yang, Yanchun Che, Jingjing Wang, Jingjing Wang, Chenghong Dong, Min Feng, Jing Pu, Lichun Wang, Yun Liao, Li Jiang, Soon Hao Tan, David Perera, Teng Huang, Zhenxin Zhou, Xuanyi Wang, Jielai Xia, Lei Guo, Ling Wang, Zhongping Xie, Wei Cui, Qunying Mao, Yan Liang, Hongling Zhao, Ruixiong Na, Pingfang Cui, Haijing Shi, Junzhi Wang, Junzhi Wang, Qihan Li · 发表于：BMC Medicine · 年份：2015 · DOI：10.1186/s12916-015-0448-7 · 被引用次数：42 · 研究领域：Viral Infections and Immunology Research、Viral gastroenteritis research and epidemiology、Animal Virus Infections Studies

BACKGROUND: To investigate the long-term effects on immunity of an inactivated enterovirus 71 (EV71) vaccine and its protective efficacy. METHODS: A sub-cohort of 1,100 volunteers from Guangxi Province in China was eligible for enrolment and randomly administered either the EV71 vaccine or a placebo on days 0 and 28 in a phase III clinical trial and then observed for the following 2 years with approval by an independent ethics committee of Guangxi Zhuang Autonomous Region, China. Serum samples from the 350 participants who provided a full series of blood samples (at all the sampling points) within the 2-year period were collected. Vaccine-induced immune effects, including the neutralizing antibody titres and cross-protection against different genotypes of EV71, were examined. This study also evaluated the protective efficacy of this vaccine based upon clinical diagnosis. RESULTS: This sub-cohort showed a >60% drop-out rate over 2 years. The seroconversion rates among the 161 immunized subjects remained >95% at the end of study. The geometric mean titres of neutralizing antibodies (anti-genotype C4) 360 days after vaccination in 350 subjects were 81.0 (subjects aged 6-11 months), 98.4 (12-23 months), 95.0 (24-35 months), and 81.8 (36-71 months). These titres subsequently increased to 423.1, 659.0, 545.0, and 321.9, respectively, at 540 days post-immunization (d.p.i.), and similar levels were maintained at 720 d.p.i. Higher IFN-γ/IL-4-specific responses to the C4 genotype of EV...