title: A booster dose of an inactivated enterovirus 71 vaccine in chinese young children: a randomized, double-blind, placebo-controlled clinical trial.
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.
authors.affiliation: School of Public Health, Southeast University.
authors.forename: Wang
authors.initials: W
authors.lastname: Shenyu
authors.affiliation: Jiangsu Provincial Center for Disease Control and Prevention, Nanjing College of Pharmacy, Third Military Medical University National Engineering Research Center for Immunological Products, Chongqing.
authors.forename: Li
authors.initials: L
authors.lastname: Jingxin
authors.affiliation: National Institute for Food and Drug Control.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhenglun
authors.affiliation: Beijing Vigoo Biological, China.
authors.forename: Li
authors.initials: L
authors.lastname: Xiuling
authors.affiliation: National Institute for Food and Drug Control.
authors.forename: Mao
authors.initials: M
authors.lastname: Qunying
authors.affiliation: Jiangsu Provincial Center for Disease Control and Prevention, Nanjing.
authors.forename: Meng
authors.initials: M
authors.lastname: Fanyue
authors.affiliation: Jiangsu Provincial Center for Disease Control and Prevention, Nanjing.
authors.forename: Wang
authors.initials: W
authors.lastname: Hua
authors.affiliation: Beijing Vigoo Biological, China.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Yuntao
authors.affiliation: National Institute for Food and Drug Control.
authors.forename: Gao
authors.initials: G
authors.lastname: Fan
authors.affiliation: Beijing Vigoo Biological, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Qinghua
authors.affiliation: Jiangsu Provincial Center for Disease Control and Prevention, Nanjing.
authors.forename: Hu
authors.initials: H
authors.lastname: Yuemei
authors.affiliation: National Institute for Food and Drug Control.
authors.forename: Yao
authors.initials: Y
authors.lastname: Xin
authors.affiliation: Beijing Vigoo Biological, China.
authors.forename: Guo
authors.initials: G
authors.lastname: Huijie
authors.affiliation: Jiangsu Provincial Center for Disease Control and Prevention, Nanjing.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Fengcai
mesh_terms: D000914:Antibodies, Viral / Q000097:blood; D044466:Asian People; D002675:Child, Preschool; D004311:Double-Blind Method; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology / Q000473:pathology; D029821:Enterovirus A, Human / Q000276:immunology*; D004769:Enterovirus Infections / Q000517:prevention & control*; D005260:Female; D006801:Humans; D007117:Immunization, Secondary / Q000009:adverse effects / Q000379:methods*; D007223:Infant; D008297:Male; D010919:Placebos / Q000008:administration & dosage; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D010919:Placebos; D015164:Vaccines, Inactivated; D014765:Viral Vaccines
keywords: booster immunization; enterovirus 71 vaccine; immunogenicity and safety