The U.S. Food and Drug Administration has declined Moderna’s request to review a novel flu vaccine utilizing Nobel Prize-winning mRNA technology, the company disclosed on Tuesday. This development showcases the FDA’s increased scrutiny of vaccines during Health Secretary Robert F. Kennedy Jr.’s tenure, especially those employing mRNA technology, which he has criticized both before and after assuming his role as the nation’s top health official.
Moderna was issued a “refusal-to-file” communication from the FDA, citing concerns regarding the methodology of a 40,000-person clinical trial comparing the efficacy of its new vaccine to a standard flu shot currently in use. The trial indicated that the new vaccine exhibited somewhat higher effectiveness in adults aged 50 and above compared to the standard shot.
Dr. Vinay Prasad, the FDA’s vaccine director, outlined in the letter that the agency deemed the application lacking an “adequate and well-controlled trial” as it did not evaluate the new shot against “the best-available standard of care in the United States at the time of the study.” The letter referenced advice provided to Moderna in 2024, during the Biden administration, which Moderna did not adhere to.
Moderna stated that the FDA had permitted the study to proceed as initially planned, despite advising the use of a different flu shot brand specifically recommended for seniors in the trial. Additionally, Moderna shared supplementary data from a separate trial comparing the new vaccine with a licensed high-dose shot intended for seniors.
Moderna’s CEO, Stephane Bancel, affirmed that the FDA did not raise any safety or efficacy concerns regarding their product. The company expressed intentions to urgently meet with the FDA and highlighted that they had sought approval for the vaccine in Europe, Canada, and Australia.
Under Kennedy’s leadership, there have been revisions to recommendations concerning COVID-19 vaccines, along with the addition of extra warnings to the two primary mRNA-based COVID vaccines. Moreover, critics of the administration’s vaccine strategy were removed from an FDA advisory panel.
In a rare move, the FDA declined to file the application, necessitating prolonged discussions between companies and FDA personnel, especially for a new vaccine. Last year, Kennedy announced the cancellation of over $500 million in contracts and funding for the development of mRNA-based vaccines.
For decades, the FDA has permitted vaccine manufacturers to swiftly update annual flu shots to target the latest strains by demonstrating their ability to elicit an immune response in patients. This approach is more efficient than conducting extended studies to monitor patient flu occurrences and outcomes.
In a memo last year, Prasad indicated that the streamlined method for updating vaccines would no longer be allowed, prompting criticism from numerous former FDA commissioners who penned an editorial denouncing the statements.
