title: Childhood vaccines and Kawasaki disease, Vaccine Safety Datalink, 1996-2006.
abstract: BACKGROUND
  Kawasaki disease is a childhood vascular disorder of unknown etiology. Concerns have been raised about vaccinations being a potential risk factor for Kawasaki disease.
  
  
  METHODS
  Data from the Vaccine Safety Datalink were collected on children aged 0-6 years at seven managed care organizations across the United States. Defining exposure as one of several time periods up to 42 days after vaccination, we conducted Poisson regressions controlling for age, sex, season, and managed care organization to determine if rates of physician-diagnosed and verified Kawasaki disease were elevated following vaccination compared to rates during all unexposed periods. We also performed case-crossover analyses to control for unmeasured confounding.
  
  
  RESULTS
  A total of 1,721,186 children aged 0-6 years from seven managed care organizations were followed for a combined 4,417,766 person-years. The rate of verified Kawasaki disease was significantly lower during the 1-42 days after vaccination (rate ratio=0.50, 95% CL=0.27-0.92) and 8-42 days after vaccination (rate ratio=0.45, 95% CL=0.22-0.90) compared to rates during unexposed periods. Breaking down the analysis by vaccination category did not identify a subset of vaccines which was solely responsible for this association. The case-crossover analyses revealed that children with Kawasaki disease had lower rates of vaccination in the 42 days prior to symptom onset for both physician-diagnosed Kawasaki disease (rate ratio=0.79, 95% CL=0.64-0.97) and verified Kawasaki disease (rate ratio=0.38, 95% CL=0.20-0.75).
  
  
  CONCLUSIONS
  Childhood vaccinations' studied did not increase the risk of Kawasaki disease; conversely, vaccination was associated with a transient decrease in Kawasaki disease incidence. Verifying and understanding this potential protective effect could yield clues to the underlying etiology of Kawasaki disease.
authors.affiliation: Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, United States. Electronic address: jabrams@cdc.gov.
authors.forename: Joseph Y
authors.initials: JY
authors.lastname: Abrams
authors.affiliation: Immunization Safety Office, Division of Healthcare Quality and Promotion, Centers for Disease Control and Prevention, Atlanta, GA, United States.
authors.forename: Eric S
authors.initials: ES
authors.lastname: Weintraub
authors.affiliation: Immunization Safety Office, Division of Healthcare Quality and Promotion, Centers for Disease Control and Prevention, Atlanta, GA, United States.
authors.forename: James M
authors.initials: JM
authors.lastname: Baggs
authors.affiliation: Immunization Safety Office, Division of Healthcare Quality and Promotion, Centers for Disease Control and Prevention, Atlanta, GA, United States.
authors.forename: Natalie L
authors.initials: NL
authors.lastname: McCarthy
authors.affiliation: Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, United States.
authors.forename: Lawrence B
authors.initials: LB
authors.lastname: Schonberger
authors.affiliation: Harvard Pilgrim Health Care Institute, Boston, MA, United States.
authors.forename: Grace M
authors.initials: GM
authors.lastname: Lee
authors.affiliation: Kaiser Permanente Vaccine Study Center, Oakland, CA, United States.
authors.forename: Nicola P
authors.initials: NP
authors.lastname: Klein
authors.affiliation: Marshfield Clinic Research Foundation, Marshfield, WI, United States.
authors.forename: Edward A
authors.initials: EA
authors.lastname: Belongia
authors.affiliation: Group Health Research Institute, Seattle, WA, United States.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Jackson
authors.affiliation: Kaiser Permanente Northwest, Portland, OR, United States.
authors.forename: Allison L
authors.initials: AL
authors.lastname: Naleway
authors.affiliation: HealthPartners Research Foundation, Minneapolis, MN, United States.
authors.forename: James D
authors.initials: JD
authors.lastname: Nordin
authors.affiliation: Kaiser Permanente Colorado, Denver, CO, United States.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Hambidge
authors.affiliation: Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, United States.
authors.forename: Ermias D
authors.initials: ED
authors.lastname: Belay
mesh_terms: D016907:Adverse Drug Reaction Reporting Systems; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D009080:Mucocutaneous Lymph Node Syndrome / Q000453:epidemiology* / Q000209:etiology*; D012044:Regression Analysis; D012307:Risk Factors; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D014611:Vaccination; D014612:Vaccines / Q000009:adverse effects*; D014657:Vasculitis
chemical_list: D014612:Vaccines
keywords: Adverse events; Kawasaki disease; Vaccine Safety Datalink; Vasculitis