title: Increased reactions to pediatric influenza vaccination following concomitant pneumococcal vaccination.
abstract: BACKGROUND
  Influenza in children causes significant morbidity and hospitalizations and also some mortality particularly in children < 5 years of age. Influenza vaccination in children has been shown to be safe and effective, but in 2010 the pediatric influenza vaccination program was suspended in Western Australia after the rate of febrile convulsions observed (9/1000 doses) was 55 times the previously reported rate. In 2009, over 80% of all children in New Brunswick were vaccinated with an adjuvanted monovalent H1N1 vaccine shown to have very high effectiveness, raising the prospect of potential hyper-responsiveness because of residual protection. We conducted enhanced post-marketing surveillance to monitor local and general reactions.
  
  
  METHODS
  Parents of participating children seen at dedicated vaccination clinics were given influenza vaccine survey kits to record local and general symptoms up to 3 days following receipt of season influenza vaccine.
  
  
  RESULTS
  Febrile reactions of ≥ 38° occurred in <10% of children who received a first dose of seasonal influenza vaccine (n = 660) and severe febrile incidents with fever ≥ 39° were uncommon. Concurrent administration of other vaccine(s) including conjugated pneumococcal vaccine appeared to increase reactogenicity. No child in the study had a febrile convulsion.
  
  
  CONCLUSIONS
  Influenza vaccines in children are safe, and this study provides a baseline for rapid assessment studies at the start of a vaccine season. Parents should be aware of increased fevers with concurrent vaccine administration, and antipyretics should be considered.
authors.affiliation: Fraser Health Authority, Surrey, British Columbia, Canada. pjvb@iinet.net.au
authors.forename: Paul G
authors.initials: PG
authors.lastname: Van Buynder
authors.forename: Gillian
authors.initials: G
authors.lastname: Frosst
authors.forename: Jan L
authors.initials: JL
authors.lastname: Van Buynder
authors.forename: Francios-William
authors.initials: FW
authors.lastname: Tremblay
authors.forename: Alie
authors.initials: A
authors.lastname: Ross
authors.forename: Claire
authors.initials: C
authors.lastname: Jardine
authors.forename: Bao Gang
authors.initials: BG
authors.lastname: Fei
mesh_terms: D002675:Child, Preschool; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology / Q000473:pathology; D005260:Female; D006801:Humans; D007115:Immunization Schedule; D007223:Infant; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000009:adverse effects*; D008297:Male; D009509:New Brunswick / Q000453:epidemiology; D022242:Pneumococcal Vaccines / Q000008:administration & dosage*; D003294:Seizures, Febrile / Q000139:chemically induced* / Q000453:epidemiology*; D014611:Vaccination / Q000009:adverse effects*
chemical_list: D007252:Influenza Vaccines; D022242:Pneumococcal Vaccines