FDA Approves First mRNA Flu Vaccine mFLUSIVA

　　On August 6,2026,the U.S.Food and Drug Administration(FDA)granted marketing approval to mFLUSIVA(development code mRNA-1010),a messenger RNA seasonal influenza vaccine developed by Moderna.This marks the first regulatory approval of an mRNA-platform influenza vaccine in the United States,signaling the entry of seasonal flu prevention into the mRNA era.The vaccine will be widely available at U.S.retail pharmacies during the 2026–2027 influenza season,addressing longstanding limitations of traditional egg-based vaccines in manufacturing flexibility and immune protection for older adults.

　　Approval Pathways and Indicated Population

　　mFLUSIVA is approved for active immunization against influenza disease caused by influenza A and B virus subtypes contained in the vaccine,indicated exclusively for adults aged 50 years and older.Approval followed a stratified approach:individuals aged 50–64 received standard approval based on complete Phase III efficacy trial data,while those aged 65 and above were granted accelerated approval based on immunogenicity endpoints.Moderna is required to conduct post-marketing confirmatory trials to verify sustained clinical protection in the elderly population;failure to do so could result in modification of the accelerated approval status.

　　Core Technological Advantages

　　mFLUSIVA is a lipid nanoparticle-encapsulated trivalent mRNA vaccine encoding hemagglutinin proteins from influenza A/H1N1,A/H3N2,and B/Victoria lineage strains.It contains no egg-derived components,making it suitable for individuals with egg allergies.Unlike conventional inactivated influenza vaccines,which require more than six months to produce via egg-based cultivation,mFLUSIVA can be manufactured in just two to three months.This shortened timeline enables rapid reformulation when circulating strains undergo significant antigenic drift,substantially improving strain matching.Each dose delivers 37.5μg of total mRNA,providing full-season protection with a single annual intramuscular injection.Leveraging Moderna’s established mRNA platform,the vaccine simultaneously elicits robust humoral and cellular immune responses,offering superior durability compared to traditional formulations.

　　Pivotal Phase III Clinical Evidence

　　Approval was supported by two global,multicenter Phase III studies enrolling over 40,000 middle-aged and older adults across 11 countries.The FLUENT pivotal trial(NCT06602024)included 40,805 participants aged 50 and above and demonstrated a 27%relative vaccine efficacy versus standard-dose inactivated influenza vaccine,with 26.1%efficacy in the 50–64 subgroup,significantly reducing PCR-confirmed influenza-like illness and meeting superiority criteria.A dedicated immunogenicity study in older adults(NCT05827978)enrolled 2,992 participants aged 65+,comparing mFLUSIVA to high-dose conventional flu vaccine.At day 29 post-vaccination,hemagglutination inhibition antibody titers and seroconversion rates met all non-inferiority margins and demonstrated statistical superiority,with immune advantage sustained beyond six months.Pooled safety data from over 42,000 subjects revealed no new serious safety signals.

　　Safety Profile and Clinical Significance

　　Common adverse reactions include injection-site pain,fatigue,myalgia,headache,and chills,predominantly mild to moderate in severity and typically resolving within approximately two days.Rates of severe adverse events and cardiovascular events were balanced between groups,with no cases of myocarditis or pericarditis detected during 42-day follow-up.The prescribing information advises monitoring for systemic inflammatory reactions shortly after vaccination and contraindicates use in individuals with a history of severe hypersensitivity to any vaccine component.

　　The approval of mFLUSIVA represents a critical milestone in extending mRNA technology from pandemic response to routine seasonal infectious disease prevention.With its egg-free composition,agile manufacturing capability,and enhanced immunogenicity,the vaccine directly addresses unmet needs among middle-aged and older adults—particularly those with egg allergies or age-related immunosenescence—enriching tiered vaccination strategies and opening a new chapter in global influenza prevention.