title: A systematic review of the efficacy of live attenuated influenza vaccine upon revaccination of children.
abstract: Four randomized, double-blind, placebo-controlled studies in 6090 children that investigated the efficacy of live attenuated influenza vaccine (LAIV) upon revaccination of children against laboratory-confirmed cases of influenza in consecutive seasons were reviewed. The efficacy in season 2 of LAIV administered over 2 consecutive seasons was 86.7% (95 % CI: 76.8%, 92.4%) against strains antigenically similar to those contained in the vaccine. The additional efficacy of LAIV administered in season 2 compared to LAIV recipients in season 1 only was 58.4% (28.3%, 75.9%). LAIV administered over 2 consecutive seasons also was more efficacious than was LAIV administered in season 2 only (relative efficacy: 53.9% [17.4%, 74.3%]). Residual efficacy of LAIV administered in season 1 only compared to placebo administered in two consecutive seasons was 56.4% (37.0%, 69.8%). This review did not find any evidence of decreasing efficacy of LAIV when administered during 2 consecutive seasons.
authors.affiliation: a AstraZeneca , Gaithersburg , MD , USA.
authors.forename: Herve
authors.initials: H
authors.lastname: Caspard
authors.affiliation: b University of Turku and Turku University Hospital , Turku , Finland.
authors.forename: Terho
authors.initials: T
authors.lastname: Heikkinen
authors.affiliation: c St. Louis University Medical Center , St. Louis , MO , USA.
authors.forename: Robert B
authors.initials: RB
authors.lastname: Belshe
authors.affiliation: c St. Louis University Medical Center , St. Louis , MO , USA.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Ambrose
mesh_terms: D002648:Child; D002675:Child, Preschool; D006801:Humans; D007117:Immunization, Secondary; D007223:Infant; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D010919:Placebos / Q000008:administration & dosage; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology
chemical_list: D007252:Influenza Vaccines; D010919:Placebos; D014613:Vaccines, Attenuated
keywords: children; efficacy; live attenuated influenza vaccine; repeat vaccination; revaccination