The FDA approved Moderna’s mRNA vaccine, mFlusiva, to prevent seasonal influenza in adults 50 years of age and older. This marks the first ever approval of an mRNA-based seasonal flu vaccine. mFlusiva received traditional approval for adults aged 50 to 64 and accelerated approval for individuals aged 65 and older. Moderna has agreed to conduct an additional study and submit further data on the vaccine’s effectiveness in adults aged 65 and older.

The FDA’s Vaccines and Related Biological Products Advisory Committee (VRBPAC) unanimously recommended mFlusiva for adults 50 years of age and older. In February, the odds of the vaccine’s approval were thrown into flux when the FDA issued Moderna a rare refusal-to-file (RTF) letter, citing concerns with the design of the phase 3 trial for the shot – which was known at the time as mRNA-1010. mFlusiva is Moderna’s 5th approved product globally and its 4th FDA-approved product.

The approval was based on data from a late-stage trial involving more than 40,000 adults aged 50 and older. The trial showed that the vaccine was 26.6% more effective than a licensed standard-dose flu vaccine. Moderna also submitted late-stage data showing that the vaccine generated stronger antibody responses than Sanofi’s high-dose flu vaccine in adults aged 65 and older – and mFlusiva will compete with flu vaccines from Sanofi, GSK, CSL Seqirus, and AstraZeneca.

mFlusiva Expectations

Moderna’s vaccine uses mRNA technology to prompt the body to produce influenza antigens and trigger an immune response. This approach could potentially allow for faster updates to match circulating strains. In contrast, traditional flu shots are primarily egg-based and contain viral proteins.

Moderna says it expects to make mFlusiva available in the U.S. for the 2026–2027 respiratory virus season. mFlusiva will join Moderna’s other mRNA vaccines: Spikevax and mNexspike for the treatment of SARS-CoV-2 and mResvia for respiratory syncytial virus.

However, analysts do not expect mFlusiva to generate meaningful revenue until the H2 of 2027 because Moderna missed the contracting cycle for the 2026 U.S. flu season. Jefferies analysts had forecast $750 million in U.S. sales of Moderna’s flu shot (mFlusiva) and combination flu-COVID vaccine (mCombriax) by 2030.

Outside the U.S., Moderna’s mFlusiva application is under review in the European Union, Canada, and Australia. While mFlusiva awaits a verdict in Europe, the EMA’s Committee for Medicinal Products for Human Use (CHMP) recommended approval of Moderna’s mCombriax, a combination mRNA vaccine for flu and COVID-19, for patients aged 50 and older.