US FDA approves first mRNA flu shot from Moderna

The U.S. Food and Drug Administration has approved Moderna's flu vaccine for people aged 50 and older, the company said on Wednesday, marking the first approval of a messenger RNA-based vaccine for seasonal flu. The shot, mFlusiva, was given a traditional approval for adults aged 50 to 64, and an accelerated approval for those 65 years and older. Moderna has agreed to run an additional study and submit more data in adults 65 and older to confirm the vaccine's benefit in that age group. "Flu remains a significant public health challenge, and mFLUSIVA provides an important new option for America’s seniors," Moderna said in a statement. The approval was based on data from a late-stage trial involving more than 40,000 adults aged 50 and older, which showed the shot was 26.6% more effective than a licensed standard-dose flu vaccine. The company also submitted separate late-stage data showing the vaccine generated stronger antibody responses than Sanofi's high-dose flu vaccine in adults 65 and older. MFlusiva would compete with flu vaccines from Sanofi , GSK, CSL Seqirus, and AstraZeneca . Moderna's vaccine uses mRNA technology to prompt the body to produce influenza antigens and trigger an immune response, an approach that could potentially allow faster updates to match circulating strains. In comparison, conventional flu shots are largely egg-based and contain viral proteins. Analysts do not expect mFlusiva to generate meaningful revenue until the second half of 2027, as Moderna missed the contracting cycle for the 2026 U.S. flu season. The company has been counting on the flu vaccine and a future COVID-flu combination shot to replace some of the lost COVID vaccine revenue and to prove the long-term commercial potential of its mRNA technology, which has met resistance from some U.S. health officials. Jefferies analysts had forecast $750 million in U.S. sales of Moderna's flu shot and combination COVID-flu vaccine by 2030. The company withdrew its application for the combo shot last year after the agency sought additional evidence demonstrating the effectiveness of its flu component. The withdrawal came amid heightened FDA scrutiny of vaccines under the agency's previous leadership, which drew criticism from industry and public health experts. Former FDA Commissioner Marty Makary and former vaccine chief Vinay Prasad were forced to resign earlier this year amid controversies over vaccine and rare-disease drug reviews, including Moderna's flu vaccine application. Acting Commissioner Kyle Diamantas has since sought to steady the agency and rebuild industry confidence.