title: Impact of maternal immunization on influenza hospitalizations in infants.
abstract: We sought to determine whether maternal vaccination during pregnancy was associated with a reduced risk of laboratory-confirmed influenza hospitalizations in infants <6 months old. Active population-based, laboratory-confirmed influenza surveillance was conducted in children hospitalized with fever and/or respiratory symptoms in 3 US counties from November through April during the 2002 through 2009 influenza seasons. The exposure, influenza vaccination during pregnancy, and the outcome, positive/negative influenza testing among their hospitalized infants, were compared using logistic regression analyses. Among 1510 hospitalized infants <6 months old, 151 (10%) had laboratory-confirmed influenza and 294 (19%) mothers reported receiving influenza vaccine during pregnancy. Eighteen (12%) mothers of influenza-positive infants and 276 (20%) mothers of influenza-negative infants were vaccinated (unadjusted odds ratio, 0.53; 95% confidence interval, 0.32-0.88 and adjusted odds ratio, 0.52; 95% confidence interval, 0.30-0.91). Infants of vaccinated mothers were 45-48% less likely to have influenza hospitalizations than infants of unvaccinated mothers. Our results support the current influenza vaccination recommendation for pregnant women.
authors.affiliation: Department of Pediatrics, Wake Forest University School of Medicine, Winston-Salem, NC, USA.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Poehling
authors.forename: Peter G
authors.initials: PG
authors.lastname: Szilagyi
authors.forename: Mary A
authors.initials: MA
authors.lastname: Staat
authors.forename: Beverly M
authors.initials: BM
authors.lastname: Snively
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Payne
authors.forename: Carolyn B
authors.initials: CB
authors.lastname: Bridges
authors.forename: Susan Y
authors.initials: SY
authors.lastname: Chu
authors.forename: Laney S
authors.initials: LS
authors.lastname: Light
authors.forename: Mila M
authors.initials: MM
authors.lastname: Prill
authors.forename: Lyn
authors.initials: L
authors.lastname: Finelli
authors.forename: Marie R
authors.initials: MR
authors.lastname: Griffin
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Edwards
mesh_terms: D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007112:Immunity, Maternally-Acquired; D007223:Infant; D007252:Influenza Vaccines / Q000008:administration & dosage*; D007251:Influenza, Human / Q000175:diagnosis / Q000517:prevention & control*; D011159:Population Surveillance; D017410:Practice Guidelines as Topic; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000517:prevention & control*; D012306:Risk; D014481:United States
chemical_list: D007252:Influenza Vaccines