Moderna’s Flu Vaccine Wins FDA Approval After an Unusual Regulatory Reversal

Moderna’s Flu Vaccine Wins FDA Approval After an Unusual Regulatory Reversal
The approval of Moderna’s mFLUSIVA marks a breakthrough for mRNA technology—but also highlights an FDA review process that changed direction within weeks.

The vaccine is the first mRNA shot approved for seasonal influenza and is authorized for adults ages 50 and older. Moderna expects to make it available for the 2026–27 flu season. The decision followed an earlier refusal by the FDA to accept the company’s application, a reversal that conservative coverage framed as the agency “reversing its own rejection.”

The more favorable interpretation emphasizes the vaccine’s potential. Moderna said the approval showed “the ongoing potential of our mRNA platform to help address important public health challenges through continued scientific innovation.” The company’s 40,000-person trial found mFLUSIVA more effective in adults 50 and older than one commonly used conventional flu vaccine, according to the reported account.

The regulatory dispute, however, centered on what the trial did not show. FDA vaccine director Vinay Prasad criticized the study for failing to include another vaccine specifically recommended for people 65 and older. Moderna responded by seeking full approval for adults ages 50 to 64 and accelerated approval for those 65 and older, while agreeing to conduct an additional study in older recipients.

That compromise leaves both sides with a point: the approval represents a significant expansion of mRNA medicine, but it is not a clean endorsement across every age group. It also leaves the FDA facing scrutiny over why its initial rejection gave way to a revised regulatory approach after discussions with Moderna.