FDA refuses to review Moderna’s mRNA flu vaccine

The Food and Drug Administration (FDA) has unexpectedly declined to review Moderna’s proposal for an mRNA influenza vaccine, a decision the company disclosed on Tuesday. This surprising turn of events marks another instance of resistance toward vaccines, particularly mRNA technology, from an agency influenced by the outspoken anti-vaccine advocate Robert F. Kennedy Jr. Since taking office, Kennedy has made significant changes, including reducing childhood vaccine recommendations and eliminating $500 million in funding aimed at mRNA vaccine research for potential pandemic responses. In a statement issued on Tuesday, Moderna expressed its astonishment at the FDA's refusal, which the agency attributed to concerns regarding the design of the Phase 3 trial for its mRNA flu vaccine, referred to as mRNA-1010. The FDA's rejection specifically focused on the comparator vaccine utilized in the trial. This clinical study enrolled nearly 41,000 participants and required a substantial financial investment. It compared the safety and effectiveness of mRNA-1010 against licensed standard-dose influenza vaccines, such as Fluarix, produced by GlaxoSmithKline. The trial concluded that mRNA-1010 outperformed the comparator vaccines. Moderna pointed out that the FDA had previously reviewed and approved its trial design on at least two occasions before submitting the application for mRNA-1010 in April 2024 and again in August 2025. The company also highlighted that Fluarix has served as a comparator in earlier flu vaccine trials, which led to the approval of other vaccines.