Open AccessThe safety and efficacy of quadrivalent live attenuated influenza vaccine in Japanese children aged 2‐18 years: Results of two phase 3 studies
Author(s) -
Mallory Raburn M.,
Yu Jing,
Kameo Sachiko,
Tanaka Michio,
Rito Ki,
Itoh Yohji,
Dubovsky Filip
Publication year - 2018
Publication title -
influenza and other respiratory viruses
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.743
H-Index - 57
eISSN - 1750-2659
pISSN - 1750-2640
DOI - 10.1111/irv.12555
Subject(s) - live attenuated influenza vaccine , medicine , clinical endpoint , placebo , adverse effect , vaccine efficacy , influenza vaccine , randomized controlled trial , vaccination , immunology , pathology , alternative medicine
Background Quadrivalent live attenuated influenza vaccine (Q/ LAIV ) has not been assessed in Japanese children. Objectives Evaluate safety and efficacy of Q/ LAIV in Japanese children. Patients/methods Two phase 3 studies were conducted in the 2014‐2015 influenza season. Study 1 was an open‐label, uncontrolled single arm, multicenter study of Q/ LAIV safety in subjects aged 2‐6 years. Study 2 was a randomized, double‐blind, placebo‐controlled multicenter study of Q/ LAIV safety and efficacy; subjects aged 7‐18 years were randomized 2:1 to receive Q/ LAIV or placebo. Primary efficacy endpoint was laboratory‐confirmed symptomatic influenza infection caused by vaccine‐matched strains; secondary endpoint evaluated efficacy against all strains regardless of match. Both studies reported solicited symptoms, adverse events ( AE s), and serious AE s. Results In Study 1, 100 subjects received Q/ LAIV . In Study 2, 1301 subjects received Q/ LAIV (n = 868) or placebo (n = 433). Treatment‐emergent AE s occurred in 42% of subjects in Study 1, and in 24.3% of subjects in the Q/ LAIV arm and in 25.9% of subjects in the placebo arm in Study 2. In Study 2, a single infection by a vaccine‐matched strain was reported in the placebo arm, resulting in a vaccine efficacy estimate of 100% (95% CI : −1875.3, 100.0); efficacy for all strains regardless of match to the vaccine was 27.5% (95% CI : 7.4, 43.0). Conclusions Quadrivalent live attenuated influenza vaccine did not meet its primary efficacy endpoint as only a single infection by a vaccine‐matched strain was detected; however, efficacy for the secondary endpoint, all strains regardless of match, was achieved. Q/ LAIV was generally well tolerated in the Japanese pediatric population.