The U.S. Food and Drug Administration has approved mFlusiva, Moderna’s mRNA-based influenza vaccine for adults aged 50 and older, marking the first flu shot built on the same technology that underpinned COVID-19 vaccines during the pandemic.
The regulator granted full approval for use in adults aged 50 to 64, while extending accelerated approval to those 65 and older, pending an additional postmarketing study. Moderna said it expects some doses to reach select retailers soon, as other flu vaccine brands begin arriving in pharmacies ahead of the fall vaccination season.
The full approval rests on a study of roughly 40,000 participants, which found that mFlusiva reduced flu cases by about 27% compared with another routinely used flu vaccine. For older adults, the accelerated authorization was based on a smaller study showing the shot generated a strong immune response relative to an existing high-dose vaccine designed for seniors.
“We are proud to bring the first mRNA flu vaccine to older adults, one of the populations most vulnerable to serious complications,” Moderna stated, noting that its data showed no major safety concerns, though the shot caused some temporary reactions.
Influenza kills tens of thousands of Americans annually, and older adults face the highest risk of severe illness. The United States already offers multiple flu vaccine options, including three formulations recommended specifically for people aged 65 or older.
The appeal of mRNA technology lies partly in speed. Flu vaccines must be reformulated each year to match circulating strains, and mRNA doses can be manufactured faster than conventional egg- or cell-based vaccines. Experts say this could prove valuable if the shape-shifting influenza virus mutates in ways that demand rapid production of new doses.
The approval extends Moderna’s push to apply its mRNA platform beyond COVID-19. The Cambridge, Massachusetts-based company has advanced candidates across several diseases, including a norovirus vaccine now in late-stage trials, as it seeks new revenue streams following the decline in pandemic-era demand.
The decision also comes amid heightened scrutiny of U.S. vaccine policy under the current administration, which has questioned aspects of immunization strategy and mRNA funding.
Moderna will continue its postmarketing study for the older-adult population as mFlusiva enters a crowded but high-stakes market. The company said it anticipates the vaccine will offer flexibility for public health responses in years when circulating strains shift unexpectedly.