title: Two-year efficacy and immunogenicity of Sinovac Enterovirus 71 vaccine against hand, foot and mouth disease in children.
abstract: OBJECTIVE
  To evaluate the efficacy and immunogenicity of the Sinovac Enterovirus 71 (EV71) vaccine for up to two years.
  
  
  METHODS
  We did a follow-up study of our initial randomized trial in 10,077 participants, who were randomized to receive EV71 vaccine or placebo in a 1:1 ratio and followed for 14 months. The extended follow-up study lasted for another 12 months and EV71-associated hand, foot, and mouth disease (HFMD) was the primary endpoint.
  
  
  RESULTS
  The EV71 vaccine showed an efficacy of 95.1% (95%CI 63.6, 99.3) against EV71-associated HFMD during the extended follow-up and an overall efficacy of 94.7% (95%CI 87.8, 97.6) for two years. The EV71 vaccine elicited a sustained high level of neutralizing antibodies in participants, and no serious adverse event was judged to be related to the vaccination.
  
  
  CONCLUSIONS
  The Sinovac EV71 vaccine could provide a sustained high protection against EV71-associated HFMDs for up to 2 years.
authors.affiliation: a College of Pharmacy , Third Military Medical University & National Engineering Research Center for Immunological Products , Chongqing , PR China.|b Vaccine Clinical Evaluation Department , Jiangsu Provincial Center for Disease Control and Prevention , Nanjing , PR China.
authors.forename: Jing-Xin
authors.initials: JX
authors.lastname: Li
authors.affiliation: c Sinovac Biotech , Beijing , PR China.
authors.forename: Yu-Fei
authors.initials: YF
authors.lastname: Song
authors.affiliation: d Statistics Department , Fourth Military Medical University , Xi'an , PR China.
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.affiliation: b Vaccine Clinical Evaluation Department , Jiangsu Provincial Center for Disease Control and Prevention , Nanjing , PR China.
authors.forename: Xue-Feng
authors.initials: XF
authors.lastname: Zhang
authors.affiliation: c Sinovac Biotech , Beijing , PR China.
authors.forename: Yuan-Sheng
authors.initials: YS
authors.lastname: Hu
authors.affiliation: b Vaccine Clinical Evaluation Department , Jiangsu Provincial Center for Disease Control and Prevention , Nanjing , PR China.
authors.forename: Yue-Mei
authors.initials: YM
authors.lastname: Hu
authors.affiliation: d Statistics Department , Fourth Military Medical University , Xi'an , PR China.
authors.forename: Jie-Lai
authors.initials: JL
authors.lastname: Xia
authors.affiliation: c Sinovac Biotech , Beijing , PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: b Vaccine Clinical Evaluation Department , Jiangsu Provincial Center for Disease Control and Prevention , Nanjing , PR China.
authors.forename: Feng-Cai
authors.initials: FC
authors.lastname: Zhu
mesh_terms: D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D002675:Child, Preschool; D018562:Disease Transmission, Infectious / Q000517:prevention & control*; D004311:Double-Blind Method; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology / Q000473:pathology; D029821:Enterovirus A, Human / Q000276:immunology*; D005260:Female; D005500:Follow-Up Studies; D006232:Hand, Foot and Mouth Disease / Q000453:epidemiology* / Q000517:prevention & control*; D006801:Humans; D007223:Infant; D008297:Male; D010919:Placebos / Q000008:administration & dosage; D016896:Treatment Outcome; D014765:Viral Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology*
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D010919:Placebos; D014765:Viral Vaccines
keywords: Sinovac Enterovirus 71 vaccine; efficacy; hand, foot, and mouth disease; immunogenicity; safety