FDA approves mRNA flu vaccine for adults 50 and older

The U.S. Food and Drug Administration has approved the nation's first messenger RNA-based seasonal influenza vaccine for adults aged 50 and older. The vaccine, developed by Moderna and to be marketed as mFlusiva, received clearance on Wednesday, August 5, 2026, following a regulatory path that included a brief rejection earlier this year.

The FDA granted traditional approval for use in adults 50 to 64 years old and accelerated approval for those 65 and older. The accelerated approval for the older age group is contingent on Moderna conducting a confirmatory post-marketing study, which the company has agreed to complete over two flu seasons.

The approval is based on data from a Phase 3 trial involving more than 40,000 adults. The data showed the vaccine was approximately 27% more effective than a licensed standard-dose flu vaccine in preventing influenza-like illness in adults 50 and older. Safety data indicated side effects were consistent with other mRNA vaccines, including injection site reactions, fatigue, headache, and muscle or joint pain, with no new serious safety concerns identified.

Moderna CEO Stéphane Bancel stated that flu remains a significant public health challenge...