New England Journal of Medicine. 2014. 370:9.
Rongcheng Li, B.S., Longding Liu, Ph.D., Zhaojun Mo, M.Sc., Xuanyi Wang, M.D., Ph.D., Jielai Xia, Ph.D., Zhenglun Liang, M.D., Ph.D., Ying Zhang, Ph.D., Yanping Li, B.S., Qunying Mao, M.Sc., Jingjing Wang, M.Sc., Li Jiang, B.S., Chenghong Dong, B.S., Yanchun Che, M.Sc., Teng Huang, M.Sc., Zhiwei Jiang, Ph.D., Zhongping Xie, B.S., Lichun Wang, B.S., Yun Liao, B.S., Yan Liang, Ph.D., Yi Nong, B.S., Jiansheng Liu, M.Sc., Hongling Zhao, B.S., Ruixiong Na, B.S., Lei Guo, Ph.D., Jing Pu, B.S., Erxia Yang, B.S., Le Sun, M.Sc., Pingfang Cui, B.S., Haijing Shi, M.Sc., Junzhi Wang, Ph.D., and Qihan Li, M.D., Ph.D.
Enterovirus 71 (EV71) is a major cause of hand, foot, and mouth disease in children and may be fatal. A vaccine against EV71 is needed.
We conducted a randomized, double-blind, placebo-controlled phase 3 trial involving healthy children 6 to 71 months of age in Guangxi Zhuang Autonomous Region, China. Two doses of an inactivated EV71 vaccine or placebo were administered intramuscularly, with a 4-week interval between doses, and children were monitored for up to 11 months. The primary end point was protection against hand, foot, and mouth disease caused by EV71.
A total of 12,000 children were randomly assigned to receive vaccine or placebo. Serum neutralizing antibodies were assessed in 549 children who received the vaccine. The seroconversion rate was 100% 4 weeks after the two vaccinations, with a geometric mean titer of 170.6. Over the course of two epidemic seasons, the vaccine efficacy was 97.4% (95% confidence interval [CI], 92.9 to 99.0) according to the intention-to-treat analysis and 97.3% (95% CI, 92.6 to 99.0) according to the per- protocol analysis. Adverse events, such as fever (which occurred in 41.6% of the participants who received vaccine vs. 35.2% of those who received placebo), were significantly more common in the week after vaccination among children who received the vaccine than among those who received placebo.
The inactivated EV71 vaccine elicited EV71-specific immune responses and protection against EV71-associated hand, foot, and mouth disease. (Funded by the National Basic Research Program and others; ClinicalTrials.gov number, NCT01569581.)