Efficacy and Safety of an mRNA Seasonal Influenza Vaccine in Adults Published May 6, 2026 N Engl J Med 2026;394:1803-1813 DOI: 10.1056/NEJMoa2516491 Abstract Background Seasonal influenza causes substantial illness and death in adults 50 years of age or older, even with current vaccines. An investigational messenger RNA (mRNA)–based vaccine called mRNA-1010 encodes hemagglutinin glycoproteins from...