title: Safety and efficacy of live attenuated influenza vaccine in children 2-7 years of age.
abstract: Three pivotal trials supported the licensure of live attenuated influenza vaccine (LAIV) for children > or =2 years of age: 2 placebo-controlled studies each conducted over 2 seasons, and a 1-year trial comparing LAIV with trivalent inactivated influenza vaccine (TIV). Analyses were conducted to evaluate the safety and efficacy of LAIV in the subgroup of children > or =2 years of age from these trials. Efficacy was demonstrated compared with placebo in children aged 2-7 years in seasons with matched strains (69.2% [95% CI: 52.7, 80.4] and 94.6% [95% CI: 88.6, 97.5]), seasons with primarily mismatched strains (87% [95% CI: 77.0, 92.6]), and during late season epidemics (73.8% [95% CI: 40.4, 89.4]). Compared with TIV recipients, LAIV recipients aged 2-5 years had 52.5% (95% CI: 26.7, 68.7) and 54.4% (95% CI: 41.8, 64.5) fewer cases of influenza illness against matched and mismatched strains, respectively. No unusual or unexpected adverse reactions were noted. The adverse reactions most commonly associated with LAIV were runny nose/nasal congestion and low-grade fever. Hospitalizations and medically significant wheezing were increased in children 6-11 and 6-23 months of age who received LAIV, respectively, but were not increased in children 2-5 years of age.
authors.affiliation: Saint Louis University Medical Center, St. Louis, MO, USA. belsherb@slu.edu
authors.forename: Robert B
authors.initials: RB
authors.lastname: Belshe
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Ambrose
authors.forename: Tingting
authors.initials: T
authors.lastname: Yi
mesh_terms: D002648:Child; D002675:Child, Preschool; D004311:Double-Blind Method; D006801:Humans; D007223:Infant; D007252:Influenza Vaccines / Q000009:adverse effects* / Q000276:immunology*; D007251:Influenza, Human / Q000453:epidemiology* / Q000517:prevention & control*; D010919:Placebos / Q000008:administration & dosage; D011446:Prospective Studies; D014613:Vaccines, Attenuated / Q000009:adverse effects / Q000276:immunology
chemical_list: D007252:Influenza Vaccines; D010919:Placebos; D014613:Vaccines, Attenuated