title: Seasonal Effectiveness of Live Attenuated and Inactivated Influenza Vaccine.
abstract: BACKGROUND
  Few observational studies have evaluated the relative effectiveness of live attenuated (LAIV) and inactivated (IIV) influenza vaccines against medically attended laboratory-confirmed influenza.
  
  
  METHODS
  We analyzed US Influenza Vaccine Effectiveness Network data from participants aged 2 to 17 years during 4 seasons (2010-2011 through 2013-2014) to compare relative effectiveness of LAIV and IIV against influenza-associated illness. Vaccine receipt was confirmed via provider/electronic medical records or immunization registry. We calculated the ratio (odds) of influenza-positive to influenza-negative participants among those age-appropriately vaccinated with either LAIV or IIV for the corresponding season. We examined relative effectiveness of LAIV and IIV by using adjusted odds ratios (ORs) and 95% confidence intervals (CIs) from logistic regression.
  
  
  RESULTS
  Of 6819 participants aged 2 to 17 years, 2703 were age-appropriately vaccinated with LAIV (n = 637) or IIV (n = 2066). Odds of influenza were similar for LAIV and IIV recipients during 3 seasons (2010-2011 through 2012-2013). In 2013-2014, odds of influenza were significantly higher among LAIV recipients compared with IIV recipients 2 to 8 years old (OR 5.36; 95% CI, 2.37 to 12.13). Participants vaccinated with LAIV or IIV had similar odds of illness associated with influenza A/H3N2 or B. LAIV recipients had greater odds of illness due to influenza A/H1N1pdm09 in 2010-2011 and 2013-2014.
  
  
  CONCLUSIONS
  We observed lower effectiveness of LAIV compared with IIV against influenza A/H1N1pdm09 but not A(H3N2) or B among children and adolescents, suggesting poor performance related to the LAIV A/H1N1pdm09 viral construct.
authors.affiliation: Atlanta Research and Education Foundation, Inc, Atlanta, Georgia; Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia; uwp0@cdc.gov.
authors.forename: Jessie R
authors.initials: JR
authors.lastname: Chung
authors.affiliation: Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia;
authors.forename: Brendan
authors.initials: B
authors.lastname: Flannery
authors.affiliation: Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia;
authors.forename: Mark G
authors.initials: MG
authors.lastname: Thompson
authors.affiliation: Baylor Scott and White Health, Texas A&M University Health Science Center College of Medicine, Temple, Texas;
authors.forename: Manjusha
authors.initials: M
authors.lastname: Gaglani
authors.affiliation: Group Health Research Institute, Seattle, Washington;
authors.forename: Michael L
authors.initials: ML
authors.lastname: Jackson
authors.affiliation: University of Michigan School of Public Health, Department of Epidemiology, Ann Arbor, Michigan;
authors.forename: Arnold S
authors.initials: AS
authors.lastname: Monto
authors.affiliation: University of Pittsburgh Schools of Health Sciences and UPMC, Pittsburgh, Pennsylvania;
authors.forename: Mary Patricia
authors.initials: MP
authors.lastname: Nowalk
authors.affiliation: Vanderbilt University Medical Center, Nashville, Tennessee;
authors.forename: H Keipp
authors.initials: HK
authors.lastname: Talbot
authors.affiliation: Department of Medicine, University of Rochester Medical Center, Rochester, New York; and.
authors.forename: John J
authors.initials: JJ
authors.lastname: Treanor
authors.affiliation: Marshfield Clinic Research Foundation, Marshfield, Wisconsin.
authors.forename: Edward A
authors.initials: EA
authors.lastname: Belongia
authors.affiliation: Baylor Scott and White Health, Texas A&M University Health Science Center College of Medicine, Temple, Texas;
authors.forename: Kempapura
authors.initials: K
authors.lastname: Murthy
authors.affiliation: Group Health Research Institute, Seattle, Washington;
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Jackson
authors.affiliation: University of Michigan School of Public Health, Department of Epidemiology, Ann Arbor, Michigan;
authors.forename: Joshua G
authors.initials: JG
authors.lastname: Petrie
authors.affiliation: University of Pittsburgh Schools of Health Sciences and UPMC, Pittsburgh, Pennsylvania;
authors.forename: Richard K
authors.initials: RK
authors.lastname: Zimmerman
authors.affiliation: Vanderbilt University Medical Center, Nashville, Tennessee;
authors.forename: Marie R
authors.initials: MR
authors.lastname: Griffin
authors.affiliation: Marshfield Clinic Research Foundation, Marshfield, Wisconsin.
authors.forename: Huong Q
authors.initials: HQ
authors.lastname: McLean
authors.affiliation: Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia;
authors.forename: Alicia M
authors.initials: AM
authors.lastname: Fry
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D053122:Influenza A Virus, H3N2 Subtype / Q000276:immunology; D009980:Influenza A virus / Q000276:immunology; D009981:Influenza B virus / Q000276:immunology; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000453:epidemiology*; D008297:Male; D012621:Seasons; D014481:United States / Q000453:epidemiology; D014613:Vaccines, Attenuated; D015164:Vaccines, Inactivated
chemical_list: D007252:Influenza Vaccines; D014613:Vaccines, Attenuated; D015164:Vaccines, Inactivated