The U.S. Food and Drug Administration has declined to review Moderna’s submission for a novel flu vaccine utilizing mRNA technology, the company revealed on Tuesday. This decision reflects the FDA’s increased scrutiny of vaccines during Health Secretary Robert F. Kennedy Jr.’s tenure, particularly those employing mRNA technology, which he has criticized both before and after assuming his role as the country’s top health official.
Moderna received a “refusal-to-file” communication from the FDA, citing concerns over the methodology of a 40,000-participant clinical trial comparing its new vaccine to a standard flu shot currently in use. The trial indicated that the new vaccine was marginally more effective in individuals aged 50 and above compared to the standard shot.
FDA’s vaccine director, Dr. Vinay Prasad, expressed that the agency deemed the application lacking an “adequate and well-controlled trial” as it did not compare the new vaccine to the “best-available standard of care in the United States at the time of the study.” Prasad’s correspondence referenced guidance provided to Moderna in 2024, during the Biden administration, which the company did not adhere to.
Moderna reported that the feedback allowed the use of the standard-dose flu shot chosen by the company but recommended a specific brand for seniors aged 65 and above in the study. Despite this, Moderna stated that the FDA approved the continuation of the study as initially planned.
Additionally, the company shared supplementary data from a separate trial comparing the new vaccine with a licensed high-dose shot administered to seniors. Moderna’s CEO, Stephane Bancel, affirmed that the FDA did not raise any safety or efficacy concerns regarding their product.
It is unusual for the FDA to refuse an application, especially for a new vaccine, necessitating extensive discussions between companies and FDA personnel over months or years. Moderna has requested an urgent meeting with the FDA and disclosed that it has sought approval for the vaccine in Europe, Canada, and Australia.
Under Kennedy’s leadership, officials have reversed COVID-19 shot recommendations, introduced extra warnings for the leading COVID vaccines utilizing mRNA technology, and excluded critics of the administration’s approach from an FDA advisory panel.
Last year, Kennedy announced the cancellation of over $500 million in contracts and funding for the development of mRNA-based vaccines. The FDA has historically permitted vaccine manufacturers to swiftly update their annual flu vaccines to target the latest strains by demonstrating an immune response in patients, a more efficient process compared to lengthy studies monitoring flu incidence and patient outcomes.
In a previous internal memo, Prasad indicated that the streamlined approach would no longer be allowed, prompting criticism from numerous former FDA commissioners who penned an editorial condemning the statements.