Approximately 12 months
The purpose of this study is to evaluate the safety and immunogenicity of a single intramuscular (IM) injection of up to 3 dose levels of Quadrivalent Influenza mRNA Vaccine MRT5410 compared to an active control (QIV SD, QIV HD [adults ≥ 65 years of age only], or RIV4) in adults 18 years of age and older.