title: Effectiveness of live-attenuated Japanese encephalitis vaccine (SA14-14-2): a case-control study.
abstract: BACKGROUND
  Japanese encephalitis is a major cause of death and disability throughout Asia, including the Indian subcontinent. Although an effective vaccine for Japanese encephalitis is available, hundreds of millions of susceptible individuals remain unimmunised because of the vaccine's cost. In 1988, an inexpensive live-attenuated vaccine (SA14-14-2) was licensed in China. We have measured the effectiveness of this vaccine.
  
  
  METHODS
  In a case-control study in rural Sichuan Province, China, the 56 cases consisted of children admitted to hospital with acute Japanese encephalitis, and were confirmed serologically. 1299 village-matched and age-matched controls were identified, and vaccination histories obtained from pre-existing written records.
  
  
  RESULTS
  The effectiveness of one dose was 80% (95% Cl 44 to 93%); that of two doses was 97.5% (86 to 99.6%). Controlling for multiple potential confounders did not alter these results.
  
  
  CONCLUSIONS
  We conclude that a regimen of two doses of live-attenuated Japanese encephalitis vaccine, administered 1 year apart, is effective in the prevention of clinically important disease. Subsequent study is needed to assure the safety of this vaccine.
authors.affiliation: Department of Biostatistics and Epidemiology, University of Pennsylvania School of Medicine, Philadelphia 19104, USA.
authors.forename: S
authors.initials: S
authors.lastname: Hennessy
authors.forename: Z
authors.initials: Z
authors.lastname: Liu
authors.forename: T F
authors.initials: TF
authors.lastname: Tsai
authors.forename: B L
authors.initials: BL
authors.lastname: Strom
authors.forename: C M
authors.initials: CM
authors.lastname: Wan
authors.forename: H L
authors.initials: HL
authors.lastname: Liu
authors.forename: T X
authors.initials: TX
authors.lastname: Wu
authors.forename: H J
authors.initials: HJ
authors.lastname: Yu
authors.forename: Q M
authors.initials: QM
authors.lastname: Liu
authors.forename: N
authors.initials: N
authors.lastname: Karabatsos
authors.forename: W B
authors.initials: WB
authors.lastname: Bilker
authors.forename: S B
authors.initials: SB
authors.lastname: Halstead
mesh_terms: D000818:Animals; D016022:Case-Control Studies; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D006224:Cricetinae; D004664:Encephalitis Virus, Japanese / Q000276:immunology*; D004672:Encephalitis, Japanese / Q000453:epidemiology / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D012449:Safety; D014611:Vaccination; D014613:Vaccines, Attenuated / Q000008:administration & dosage; D014765:Viral Vaccines / Q000008:administration & dosage
chemical_list: D014613:Vaccines, Attenuated; D014765:Viral Vaccines