This is a Phase 3, randomized, observer-blinded study to evaluate the efficacy, safety, tolerability, and immunogenicity of a quadrivalent influenza modRNA vaccine (qIRV) encoding HA of 4 seasonally recommended strains (2 A strains and 2 B strains) compared to licensed quadrivalent influenza vaccine (QIV) in healthy adults 18 years of age and older.~Participants may be enrolled in either the reactogenicity subset, immunogenicity subset, or both subsets. Efficacy will be assessed in this study through surveillance for influenza-like illness.
This is a Phase 3, randomized, observer-blinded study to evaluate the efficacy, safety, tolerability, and immunogenicity of a single dose of a quadrivalent influenza modRNA vaccine compared to licensed inactivated influenza vaccine in healthy adults 18 years of age and older.