FDA Won't Even Review mRNA Flu Vaccine Application

Moderna just got an unusually cold shoulder from the FDA over its latest vaccine push, the New York Times reports. The company says regulators have refused to even review its application for an experimental mRNA flu shot, issuing a rare "refuse to file" letter that short-circuits the normal, months-long evaluation process. The agency's top vaccine official, Dr. Vinay Prasad, concluded Moderna's large, 41,000-person trial wasn't "adequate and well-controlled" because the shot was tested against GSK's Fluarix, which he said doesn't represent the strongest flu vaccine available. The letter did not point to safety or effectiveness problems with Moderna's product itself, according to the company.

Moderna President Stephen Hoge called the move "confusing" and said the FDA had previously signaled its trial design, including the comparator vaccine, would be a matter for review, not rejection at the door. The decision lands amid a broader shift in federal health policy under Health Secretary Robert F. Kennedy Jr., who has sharply criticized mRNA vaccines and cut funding for related research. Moderna's mRNA flu shot is under review in Europe, Canada, and Australia, but no country has yet cleared an mRNA-based flu vaccine. The company has asked for another meeting with the FDA as it tries to salvage the project, backed by a $750 million investment from Blackstone. The trial had concluded the mRNA shot was somewhat more effective than the standard shot in adults 50 and over, the AP reports.