The FDA has approved the first mRNA-based flu vaccine in the United States, giving Americans age 50 and older a new option for protection against influenza as the country approaches the fall flu season.
The vaccine, called mFlusiva and developed by Moderna, uses the same type of mRNA technology that became widely known through COVID-19 vaccines. Moderna expects the new flu shot to become available soon at select retailers, just as pharmacies begin preparing for this year’s seasonal vaccination campaign.
For adults ages 50 to 64, the FDA granted full approval after a large study involving about 40,000 participants. The study found 27% fewer laboratory-confirmed flu cases among people who received mFlusiva compared with those who received a conventional flu vaccine. For adults 65 and older, the vaccine received accelerated approval based on evidence that it produced a strong immune response, with additional research required to confirm its effectiveness in that age group.
The arrival of an mRNA flu vaccine could also change how quickly manufacturers respond to evolving influenza strains. Traditional flu vaccines must be formulated months before flu season begins, while mRNA vaccines can generally be manufactured more quickly. That could eventually give vaccine makers greater flexibility when circulating flu strains change unexpectedly.
The new vaccine joins several existing flu-shot options already available in the United States, including vaccines specifically recommended for older adults. But mFlusiva marks a significant expansion of mRNA technology beyond COVID-19 and gives millions of Americans another choice as the 2026-27 flu season approaches.
