title: Safety and effectiveness of a 2009 H1N1 vaccine in Beijing.
abstract: BACKGROUND
  After the first monovalent 2009 pandemic influenza A (H1N1) vaccine became available in September 2009, Chinese officials conducted a mass vaccination program in Beijing. We evaluated the safety and effectiveness of the vaccine.
  
  
  METHODS
  During a 5-day period in September 2009, a total of 95,244 children and adults received the PANFLU.1 vaccine (Sinovac Biotech), a monovalent split-virion vaccine of 15 μg of hemagglutinin antigen without adjuvant. We assessed adverse events after immunization through an enhanced passive-surveillance system and through active surveillance, using diary cards and telephone interviews. Active surveillance for neurologic diseases was implemented in hospitals citywide. To assess vaccine effectiveness, we compared the rates of reported laboratory-confirmed cases of 2009 H1N1 virus infection in students who received the vaccine with the rates in those who did not receive the vaccine, starting 2 weeks after the mass vaccination.
  
  
  RESULTS
  As of December 31, 2009, adverse events were reported by 193 vaccine recipients. Through hospital-based active surveillance, 362 cases of incident neurologic diseases were identified within 10 weeks after the mass vaccination, including 27 cases of the Guillain-Barré syndrome. None of the neurologic conditions occurred among vaccine recipients. From 245 schools, 25,037 students participated in the mass vaccination and 244,091 did not. During the period from October 9 through November 15, 2009, the incidence of confirmed cases of 2009 H1N1 virus infection per 100,000 students was 35.9 (9 of 25,037) among vaccinated students and 281.4 (687 of 244,091) among unvaccinated students. Thus, the estimated vaccine effectiveness was 87.3% (95% confidence interval, 75.4 to 93.4).
  
  
  CONCLUSIONS
  Among 95,244 children and adults in Beijing, the PANFLU.1 vaccine had a safety profile similar to those of seasonal influenza vaccines and appeared to be effective against confirmed H1N1 virus infection in school-age children. (Funded by the Beijing Municipal Health Bureau.).
authors.affiliation: Beijing Centers for Disease Control and Prevention, Beijing.
authors.forename: Jiang
authors.initials: J
authors.lastname: Wu
authors.forename: Fujie
authors.initials: F
authors.lastname: Xu
authors.forename: Li
authors.initials: L
authors.lastname: Lu
authors.forename: Min
authors.initials: M
authors.lastname: Lu
authors.forename: Liang
authors.initials: L
authors.lastname: Miao
authors.forename: Ting
authors.initials: T
authors.lastname: Gao
authors.forename: Wenyan
authors.initials: W
authors.lastname: Ji
authors.forename: Luodan
authors.initials: L
authors.lastname: Suo
authors.forename: Donglei
authors.initials: D
authors.lastname: Liu
authors.forename: Rui
authors.initials: R
authors.lastname: Ma
authors.forename: Rui
authors.initials: R
authors.lastname: Yu
authors.forename: Jiazi
authors.initials: J
authors.lastname: Zhangzhu
authors.forename: Weixiang
authors.initials: W
authors.lastname: Liu
authors.forename: Yang
authors.initials: Y
authors.lastname: Zeng
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Li
authors.forename: Xuechun
authors.initials: X
authors.lastname: Zhang
authors.forename: Xinghuo
authors.initials: X
authors.lastname: Pang
authors.forename: Ying
authors.initials: Y
authors.lastname: Deng
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D004196:Disease Outbreaks / Q000517:prevention & control; D020275:Guillain-Barre Syndrome / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D053118:Influenza A Virus, H1N1 Subtype; D007252:Influenza Vaccines / Q000009:adverse effects / Q000276:immunology; D007251:Influenza, Human / Q000453:epidemiology / Q000517:prevention & control*; D032541:Mass Vaccination; D008875:Middle Aged; D009422:Nervous System Diseases / Q000453:epidemiology; D011159:Population Surveillance; D012306:Risk; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D007252:Influenza Vaccines