title: Safety of quadrivalent human papillomavirus vaccine administered routinely to females.
abstract: OBJECTIVE
  To assess the safety of the quadrivalent human papillomavirus vaccine (HPV4) in females following routine administration.
  
  
  METHODS
  In a cohort of vaccinated females, we compared the risk of emergency department visits and hospitalizations during the interval soon after vaccination with risk during a comparison interval more remote from vaccination.
  
  
  METHODS
  Kaiser Permanente in California.
  
  
  METHODS
  All females who received the HPV4 vaccine.
  
  
  METHODS
  One or more doses of HPV4 between August 2006 and March 2008.
  
  
  METHODS
  Outcomes were emergency department visits and hospitalizations, grouped into predefined diagnostic categories. Within diagnostic groups, we used odds ratios (ORs) to estimate whether each subject had any outcome in postvaccination risk intervals (days 1-60, days 1-14, and day 0), compared with a control interval distant in time from vaccination.
  
  
  RESULTS
  One hundred eighty-nine thousand six hundred twenty-nine females received at least 1 dose and 44 001 received 3 HPV4 doses. Fifty categories had significantly elevated ORs during at least 1 risk interval. Medical record review revealed that most diagnoses were present before vaccination or diagnostic workups were initiated at the vaccine visit. Only skin infections during days 1 to 14 (OR, 1.8; 95% CI, 1.3-2.4) and syncope on day of vaccination (OR, 6.0; 95% CI, 3.9-9.2) were noted by an independent Safety Review Committee as likely associations with HPV4.
  
  
  CONCLUSIONS
  The quadrivalent human papillomavirus vaccine was associated with same-day syncope and skin infections in the 2 weeks after vaccination. This study did not detect evidence of new safety concerns among females 9 to 26 years of age secondary to vaccination with HPV4.
authors.affiliation: Kaiser Permanente Vaccine Study Center, Oakland, CA 94612, USA. nicola.klein@kp.org
authors.forename: Nicola P
authors.initials: NP
authors.lastname: Klein
authors.forename: John
authors.initials: J
authors.lastname: Hansen
authors.forename: Chun
authors.initials: C
authors.lastname: Chao
authors.forename: Christine
authors.initials: C
authors.lastname: Velicer
authors.forename: Michael
authors.initials: M
authors.lastname: Emery
authors.forename: Jeff
authors.initials: J
authors.lastname: Slezak
authors.forename: Ned
authors.initials: N
authors.lastname: Lewis
authors.forename: Kamala
authors.initials: K
authors.lastname: Deosaransingh
authors.forename: Lina
authors.initials: L
authors.lastname: Sy
authors.forename: Bradley
authors.initials: B
authors.lastname: Ackerson
authors.forename: T Craig
authors.initials: TC
authors.lastname: Cheetham
authors.forename: Kai-Li
authors.initials: KL
authors.lastname: Liaw
authors.forename: Harpreet
authors.initials: H
authors.lastname: Takhar
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Jacobsen
mesh_terms: D000293:Adolescent; D000328:Adult; D002140:California; D002648:Child; D015331:Cohort Studies; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007115:Immunization Schedule; D016017:Odds Ratio; D053918:Papillomavirus Vaccines / Q000008:administration & dosage / Q000009:adverse effects*; D011358:Product Surveillance, Postmarketing; D012189:Retrospective Studies; D012306:Risk; D017192:Skin Diseases, Bacterial / Q000209:etiology*; D013575:Syncope / Q000209:etiology*; D013997:Time Factors; D055815:Young Adult
chemical_list: D053918:Papillomavirus Vaccines