title: Evaluation of immunization rates and safety among children with inborn errors of metabolism.
abstract: BACKGROUND
  Children with inherited metabolic disorders are a potential high-risk group for vaccine-preventable diseases, yet information regarding immunization rates and vaccine safety within this population is limited.
  
  
  METHODS
  Using Northern California Kaiser Permanente's electronic medical record, we identified children with inborn errors of metabolism from 1990 to 2007. We assessed immunization rates among infants with inborn errors of metabolism born at Northern California Kaiser Permanente matched to healthy infants (1 to 20), comparing both vaccines received by 2 years of age and age at vaccination. We assessed postvaccination adverse events among children up to 18 years old with inborn errors of metabolism, separately comparing emergency-department visits and hospitalizations during postvaccine days 0 to 30 (primary) and days 0 to 14 (secondary).
  
  
  RESULTS
  Comparing infants with inborn errors of metabolism (n = 77) versus matched control subjects (n = 1540), similar proportions were up to date for vaccines at 2 years of age, and there was no evidence of delay in receipt of recommended vaccines during the first year. Vaccination of children with inborn errors of metabolism (n = 271) was not associated with any significant increase in emergency-department visits or hospitalizations during the 30 days after vaccination. Secondary analyses suggested that there may be increased rates of hospitalizations 2 weeks after vaccination for the sickest 1- to 4-year-old children.
  
  
  CONCLUSIONS
  Children with inborn errors of metabolism at Northern California Kaiser Permanente received vaccines on the same immunization schedule as healthy infants. Immunization was not associated with increased risk for serious adverse events during the month after vaccination, providing overall reassurance that routine vaccination of children with inborn errors of metabolism does not result in adverse effects.
authors.affiliation: Kaiser Permanente Vaccine Study Center, 1 Kaiser Plaza, 16th Floor, Oakland, CA 94612, USA. nicola.klein@kp.org
authors.forename: Nicola P
authors.initials: NP
authors.lastname: Klein
authors.forename: Laurie
authors.initials: L
authors.lastname: Aukes
authors.forename: Janelle
authors.initials: J
authors.lastname: Lee
authors.forename: Bruce
authors.initials: B
authors.lastname: Fireman
authors.forename: Stuart K
authors.initials: SK
authors.lastname: Shapira
authors.forename: Barbara
authors.initials: B
authors.lastname: Slade
authors.forename: Roger
authors.initials: R
authors.lastname: Baxter
authors.forename: Marshall
authors.initials: M
authors.lastname: Summar
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002140:California; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003140:Communicable Disease Control; D016208:Databases, Factual; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007114:Immunization / Q000009:adverse effects / Q000379:methods* / Q000706:statistics & numerical data*; D007115:Immunization Schedule; D007223:Infant; D008297:Male; D008661:Metabolism, Inborn Errors / Q000175:diagnosis* / Q000276:immunology*; D012016:Reference Values; D012189:Retrospective Studies; D018570:Risk Assessment; D017751:Safety Management; D012737:Sex Factors; D013997:Time Factors; D014611:Vaccination / Q000009:adverse effects / Q000379:methods; D014612:Vaccines / Q000008:administration & dosage / Q000009:adverse effects
chemical_list: D014612:Vaccines