An integrated, multistudy analysis of the safety of Ann Arbor strain live attenuated influenza vaccine in children aged 2-17 years

Background Trivalent, Ann Arbor strain, live attenuated influenza vaccine (LAIV) is approved in several countries for use in eligible children aged >= 2 years. Objective To describe the safety of Ann Arbor strain LAIV in children aged 2-17 years. Methods An integrated analysis of randomized, controlled trials of LAIV. Results A total of 4245 and 10 693 children received >= 1 dose of LAIV in year 1 of 6 trivalent inactivated influenza vaccine (TIV)-controlled and 14 placebo-controlled studies, respectively; 3212 children were revaccinated in year 2 of 4 placebo-controlled studies. Compared with placebo for days 0-10 post-vaccination, LAIV recipients exhibited increased runny/stuffy nose (+7%), headache (+7%), and tiredness/decreased activity (+2%) after dose 1; and a higher rate of decreased appetite (+4%) after year 2 revaccination. Compared with TIV, only runny/stuffy nose was increased (dose 1, +12%; dose 2, +4%). Compared with initial vaccination, LAIV reactogenicity was lower after dose 2 in year 1 and revaccination in year 2. Unsolicited adverse events (AEs) increased with LAIV in some comparisons were headache, nasal congestion/rhinorrhea, rhinitis, and pyrexia; ear pain and lower respiratory illness were decreased. There was no evidence of an increase in any potential vaccine-related serious AE in LAIV recipients. Among children aged 2-17 years and specifically aged 24-35 months, there was no evidence that lower respiratory illness or wheezing illness occurred at a higher rate in LAIV recipients. Conclusion This analysis supports the safety of Ann Arbor strain LAIV in children aged 2-17 years and provides a consensus assessment of events expected after vaccination.