title: Asthma exacerbations among asthmatic children receiving live attenuated versus inactivated influenza vaccines.
abstract: To investigate whether there is a difference in the risk of asthma exacerbations between children with pre-existing asthma who receive live attenuated influenza vaccine (LAIV) compared with inactivated influenza vaccine (IIV).
  
  
  
  We identified IIV and LAIV immunizations occurring between July 1, 2007 and March 31, 2014 among Kaiser Permanente Northern California members aged 2 to <18years with a history of asthma, and subsequent asthma exacerbations seen in the inpatient or Emergency Department (ED) setting. We calculated the ratio of the odds (OR) of an exacerbation being in the risk interval (1-14days) versus the comparison interval (29-42days) following immunization, separately for LAIV and IIV, and then examined whether the OR differed between children receiving LAIV and those receiving IIV ("difference-in-differences").
  
  
  
  Among 387,633 immunizations, 85% were IIV and 15% were LAIV. Children getting LAIV vs. IIV were less likely to have "current or recent, persistent" asthma (25% vs. 47%), and more likely to have "remote history" of asthma (47% vs. 25%). Among IIV-vaccinated asthmatic children, the OR of an inpatient/ED asthma exacerbation was 0.97 (95% CI: 0.82-1.15). Among LAIV-vaccinated asthmatic children the OR was 0.38 (95% CI: 0.17-0.90). In the difference-in-differences analysis, the odds of asthma exacerbation following LAIV were less than IIV (Ratio of ORs: 0.40, CI: 0.17-0.95, p value: 0.04).
  
  
  
  Among children ≥2years old with asthma, we found no increased risk of asthma exacerbation following LAIV or IIV, and a decreased risk following LAIV compared to IIV.
authors.affiliation: Kaiser Permanente Vaccine Study Center and Division of Research, Kaiser Permanente Medical Care Program, Northern California Region, Oakland, CA, United States. Electronic address: tom.ray@kp.org.
authors.forename: G Thomas
authors.initials: GT
authors.lastname: Ray
authors.affiliation: Kaiser Permanente Vaccine Study Center and Division of Research, Kaiser Permanente Medical Care Program, Northern California Region, Oakland, CA, United States.
authors.forename: Ned
authors.initials: N
authors.lastname: Lewis
authors.affiliation: Kaiser Permanente Vaccine Study Center and Division of Research, Kaiser Permanente Medical Care Program, Northern California Region, Oakland, CA, United States.
authors.forename: Kristin
authors.initials: K
authors.lastname: Goddard
authors.affiliation: Kaiser Permanente Vaccine Study Center and Division of Research, Kaiser Permanente Medical Care Program, Northern California Region, Oakland, CA, United States.
authors.forename: Pat
authors.initials: P
authors.lastname: Ross
authors.affiliation: Immunization Safety Office, Centers for Disease Control and Prevention, Atlanta, GA, United States.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Duffy
authors.affiliation: Immunization Safety Office, Centers for Disease Control and Prevention, Atlanta, GA, United States.
authors.forename: Frank
authors.initials: F
authors.lastname: DeStefano
authors.affiliation: Kaiser Permanente Vaccine Study Center and Division of Research, Kaiser Permanente Medical Care Program, Northern California Region, Oakland, CA, United States.
authors.forename: Roger
authors.initials: R
authors.lastname: Baxter
authors.affiliation: Kaiser Permanente Vaccine Study Center and Division of Research, Kaiser Permanente Medical Care Program, Northern California Region, Oakland, CA, United States.
authors.forename: Nicola P
authors.initials: NP
authors.lastname: Klein
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000150:complications*; D002140:California / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D006801:Humans; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000009:adverse effects*; D007251:Influenza, Human / Q000517:prevention & control*; D008297:Male; D013224:Status Asthmaticus / Q000139:chemically induced* / Q000453:epidemiology*; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000009:adverse effects; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000009:adverse effects
chemical_list: D007252:Influenza Vaccines; D014613:Vaccines, Attenuated; D015164:Vaccines, Inactivated
keywords: Asthma; Influenza; Safety; Vaccines