The announcement came on Tuesday that the U.S. Food and Drug Administration has declined to review Moderna’s submission for a novel flu vaccine utilizing mRNA technology. This decision underscores the FDA’s increased scrutiny of vaccines during Health Secretary Robert F. Kennedy Jr.’s tenure, especially those incorporating mRNA technology, which he has criticized both before and after assuming his current role.
Moderna received a “refusal-to-file” communication from the FDA, citing concerns regarding the methodology of a 40,000-person clinical trial that compared their new vaccine to a standard flu shot. The trial indicated that the new vaccine exhibited superior efficacy in adults aged 50 and above compared to the standard shot.
FDA’s vaccine director, Dr. Vinay Prasad, expressed that the application lacked an “adequate and well-controlled trial” as it did not compare the new vaccine against the best available standard of care in the U.S. at the time of the study. Moderna had not followed advice given by FDA officials in 2024 under the Biden administration.
Despite some discrepancies, Moderna proceeded with the study as planned. The company shared additional data from a separate trial comparing the new vaccine to a licensed high-dose shot for seniors with the FDA, which did not raise any safety or efficacy concerns.
It is uncommon for the FDA to decline an application, particularly for a new vaccine, as it necessitates extensive discussions between companies and FDA personnel over an extended period. Moderna has urged an urgent meeting with the FDA, while also seeking approval for the vaccine in Europe, Canada, and Australia.
Under Kennedy’s leadership, there have been notable changes in vaccine recommendations, including the addition of warnings to leading COVID-19 vaccines utilizing mRNA technology and the removal of critics from an FDA advisory panel.
Kennedy’s department previously announced the cancellation of over $500 million in contracts and funding for mRNA vaccine development. The FDA traditionally allows vaccine manufacturers to swiftly update annual flu shots to target current strains by demonstrating immune response, a more efficient process than prolonged studies monitoring flu incidence and outcomes.
An internal memo by Prasad last year outlined a shift away from the streamlined approach, prompting criticism from former FDA commissioners.