A Study to Evaluate the Immunogenicity of Quadrivalent Live Attenuated Influenza Vaccine (LAIV) in Children

The randomized, double-blind study was designed to demonstrate the immunologic noninferiority of Q/LAIV compared to FluMist in children 2-17 years by comparing the strain-specific post-dose geometric mean titers of hemagglutination inhibition antibodies. Children were randomized 3:1:1 to receive Q/LAIV or one of two FluMist vaccines. Subjects 9-17 years of age received a single dose, and those 2-8 years of age received two doses one month apart. Serum was obtained 1 month after dose 1 except in influenza vaccine-naive subjects 2-8 years old, when it was obtained after dose 2. Safety and tolerability were also assessed.