title: [Meta analysis on the effectiveness of inactivated influenza vaccine].
abstract: OBJECTIVE
  To understand the effectiveness of inactivated influenza vaccines (IIV).
  
  
  METHODS
  We did a Meta analysis on IIV effectiveness with papers published during March 1998 and May 2008 in Chinese journals, using fixed model or random model according to the heterogeneity of the studies.
  
  
  RESULTS
  A total number of 13 studies were included, of which 11 were cohort studies and 2 were randomized controlled trials. Through Meta analysis on cohort studies regarding the effectiveness against influenza like illness (ILI), we noticed that the effectiveness of the vaccine was 66% (95% CI: 51%-76%) in children and adolescents, but 47% (25%-63%) in adults, and 53% (20%-72%) in the elderly.
  
  
  CONCLUSIONS
  IIV was effective in protecting against influenza like illness.
authors.affiliation: Public Health School, Peking University Health Science Center, Beijing 100191, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xing
authors.forename: Min
authors.initials: M
authors.lastname: Liu
mesh_terms: D006801:Humans; D007252:Influenza Vaccines / Q000276:immunology / Q000627:therapeutic use*; D007251:Influenza, Human / Q000517:prevention & control*; D015164:Vaccines, Inactivated / Q000276:immunology / Q000627:therapeutic use
chemical_list: D007252:Influenza Vaccines; D015164:Vaccines, Inactivated