Wang Shenyu1, Li Jingxin2, Liang Zhenglun3, Li Xiuling4, Mao Qunying3, Meng Fanyue5, Wang Hua5, Zhang Yuntao4, Gao Fan3, Chen Qinghua4, Hu Yuemei5, Yao Xin3, Guo Huijie4, Zhu Fengcai5. 1. School of Public Health, Southeast University. 2. Jiangsu Provincial Center for Disease Control and Prevention, Nanjing College of Pharmacy, Third Military Medical University National Engineering Research Center for Immunological Products, Chongqing. 3. National Institute for Food and Drug Control. 4. Beijing Vigoo Biological, China. 5. Jiangsu Provincial Center for Disease Control and Prevention, Nanjing.
Abstract
BACKGROUND: A significant waning of enterovirus 71 (EV71) antibody titer after priming immunization with an inactivated EV71 vaccine implied the potential need for a booster dose. METHODS: In this randomized, double-blind, placebo-controlled clinical trial, we recruited participants who had received at least 1 dose of priming EV71 vaccine in an early phase 2 clinical trial that was conducted in healthy infants and children aged 6-35 months. All participants were grouped according to the priming EV71 vaccine formulations (160 U, 320 U, and 640 U with adjuvant and 640 U without adjuvant) and then randomly assigned (ratio, 2:1) to receive a booster dose of vaccine or placebo within each formulation group. The primary end point was the geometric mean titer 28 days after the booster dose. RESULTS:A total of 773 participants were enrolled. Significantly greater immunological responses were induced by the booster shot of all 4 formulations of EV71 vaccine, compared with that induced by placebo (P < .0001). The frequencies of adverse reactions were similar between vaccine and placebo groups within each formulation group. CONCLUSIONS: A booster dose of EV71 vaccine 1 year after the priming EV71 immunization shows excellent immunogenicity and good safety profile. Clinical Trials Registration: NCT01734408.
RCT Entities:
BACKGROUND: A significant waning of enterovirus 71 (EV71) antibody titer after priming immunization with an inactivated EV71 vaccine implied the potential need for a booster dose. METHODS: In this randomized, double-blind, placebo-controlled clinical trial, we recruited participants who had received at least 1 dose of priming EV71 vaccine in an early phase 2 clinical trial that was conducted in healthy infants and children aged 6-35 months. All participants were grouped according to the priming EV71 vaccine formulations (160 U, 320 U, and 640 U with adjuvant and 640 U without adjuvant) and then randomly assigned (ratio, 2:1) to receive a booster dose of vaccine or placebo within each formulation group. The primary end point was the geometric mean titer 28 days after the booster dose. RESULTS: A total of 773 participants were enrolled. Significantly greater immunological responses were induced by the booster shot of all 4 formulations of EV71 vaccine, compared with that induced by placebo (P < .0001). The frequencies of adverse reactions were similar between vaccine and placebo groups within each formulation group. CONCLUSIONS: A booster dose of EV71 vaccine 1 year after the priming EV71 immunization shows excellent immunogenicity and good safety profile. Clinical Trials Registration: NCT01734408.