title: Association Between Hospitalization With Community-Acquired Laboratory-Confirmed Influenza Pneumonia and Prior Receipt of Influenza Vaccination.
abstract: OBJECTIVE
  Few studies have evaluated the relationship between influenza vaccination and pneumonia, a serious complication of influenza infection.
  
  
  OBJECTIVE
  To assess the association between influenza vaccination status and hospitalization for community-acquired laboratory-confirmed influenza pneumonia.
  
  
  METHODS
  The Etiology of Pneumonia in the Community (EPIC) study was a prospective observational multicenter study of hospitalizations for community-acquired pneumonia conducted from January 2010 through June 2012 at 4 US sites. In this case-control study, we used EPIC data from patients 6 months or older with laboratory-confirmed influenza infection and verified vaccination status during the influenza seasons and excluded patients with recent hospitalization, from chronic care residential facilities, and with severe immunosuppression. Logistic regression was used to calculate odds ratios, comparing the odds of vaccination between influenza-positive (case) and influenza-negative (control) patients with pneumonia, controlling for demographics, comorbidities, season, study site, and timing of disease onset. Vaccine effectiveness was estimated as (1 - adjusted odds ratio) × 100%.
  
  
  METHODS
  Influenza vaccination, verified through record review.
  
  
  METHODS
  Influenza pneumonia, confirmed by real-time reverse-transcription polymerase chain reaction performed on nasal/oropharyngeal swabs.
  
  
  RESULTS
  Overall, 2767 patients hospitalized for pneumonia were eligible for the study; 162 (5.9%) had laboratory-confirmed influenza. Twenty-eight of 162 cases (17%) with influenza-associated pneumonia and 766 of 2605 controls (29%) with influenza-negative pneumonia had been vaccinated. The adjusted odds ratio of prior influenza vaccination between cases and controls was 0.43 (95% CI, 0.28-0.68; estimated vaccine effectiveness, 56.7%; 95% CI, 31.9%-72.5%).
  
  
  CONCLUSIONS
  Among children and adults hospitalized with community-acquired pneumonia, those with laboratory-confirmed influenza-associated pneumonia, compared with those with pneumonia not associated with influenza, had lower odds of having received influenza vaccination.
authors.affiliation: Vanderbilt University School of Medicine, Nashville, Tennessee2Geriatric Research Education Clinical Center (GRECC), VA Tennessee Valley, Nashville.
authors.forename: Carlos G
authors.initials: CG
authors.lastname: Grijalva
authors.affiliation: Vanderbilt University School of Medicine, Nashville, Tennessee.
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Vanderbilt University School of Medicine, Nashville, Tennessee.
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Williams
authors.affiliation: Vanderbilt University School of Medicine, Nashville, Tennessee.
authors.forename: Wesley H
authors.initials: WH
authors.lastname: Self
authors.affiliation: University of Utah School of Medicine, Salt Lake City.
authors.forename: Krow
authors.initials: K
authors.lastname: Ampofo
authors.affiliation: University of Utah School of Medicine, Salt Lake City.
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Pavia
authors.affiliation: University of Utah School of Medicine, Salt Lake City.
authors.forename: Chris R
authors.initials: CR
authors.lastname: Stockmann
authors.affiliation: University of Tennessee School of Medicine, Memphis.
authors.forename: Jonathan
authors.initials: J
authors.lastname: McCullers
authors.affiliation: University of Tennessee School of Medicine, Memphis.
authors.forename: Sandra R
authors.initials: SR
authors.lastname: Arnold
authors.affiliation: Northwestern University School of Medicine, Chicago, Illinois.
authors.forename: Richard G
authors.initials: RG
authors.lastname: Wunderink
authors.affiliation: Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Evan J
authors.initials: EJ
authors.lastname: Anderson
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Lindstrom
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Alicia M
authors.initials: AM
authors.lastname: Fry
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia8Battelle Memorial Institute, Atlanta, Georgia.
authors.forename: Ivo M
authors.initials: IM
authors.lastname: Foppa
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Lyn
authors.initials: L
authors.lastname: Finelli
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Bramley
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Seema
authors.initials: S
authors.lastname: Jain
authors.affiliation: Vanderbilt University School of Medicine, Nashville, Tennessee2Geriatric Research Education Clinical Center (GRECC), VA Tennessee Valley, Nashville.
authors.forename: Marie R
authors.initials: MR
authors.lastname: Griffin
authors.affiliation: Vanderbilt University School of Medicine, Nashville, Tennessee.
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Edwards
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D007252:Influenza Vaccines / Q000008:administration & dosage*; D007251:Influenza, Human / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011024:Pneumonia, Viral / Q000175:diagnosis / Q000453:epidemiology*; D011446:Prospective Studies; D014611:Vaccination / Q000706:statistics & numerical data*
chemical_list: D007252:Influenza Vaccines