This randomized, observer-blind, placebo-controlled multicenter, Phase 3 study will be conducted at multiple sites. The composition of the Quadrivalent VLP Influenza Vaccine to be used in this study includes a mix of recombinant H1, H3, and two B hemagglutinin proteins expressed as VLPs for the 2017-2018 influenza virus strains.~Approximately 10,000 healthy male and female subjects aged 18 to 64 years will be randomized in a 1:1 ratio into one of two parallel treatment groups, such that approximately 5,000 subjects will receive the Quadrivalent VLP Influenza Vaccine at a dose of 30 μg/strain and approximately 5,000 subjects will receive the placebo. Within the two treatment groups, subjects will be stratified by site and two age groups (18-49 years of age and 50-64 years of age in a 1:1 ratio).~Subjects will participate in this study for approximately eight to ten months, during which a first visit will be scheduled on Day 0 for screening and vaccine administration.
This Phase 3 study is intended to assess the efficacy of the Quadrivalent VLP Influenza Vaccine during the 2017-2018 influenza season in healthy adults 18 to 64 years of age. One dose of Quadrivalent Virus-Like Particles (VLP) Influenza Vaccine (30 μg/strain) or of placebo will be administered to approximately 10,000 subjects.