Urge FDA to Provide Fair Review of Moderna's mRNA Flu Vaccine Application

I am writing to express serious concern about the FDA's February 3, 2025 refuse-to-file decision on Moderna's mRNA seasonal flu vaccine application. This decision appears inconsistent with the agency's own guidance and threatens to undermine a promising public health advancement. The FDA rejected Moderna's application claiming the control arm did not reflect the best available standard of care, yet the company used Fluarix, a standard-dose seasonal flu vaccine, as a comparator in a trial involving 40,700 participants. Moderna states the FDA agreed to this trial design in April 2024. As recently as August 2024, the agency indicated it would review the filing and assess comparator issues during the review process. The company also provided additional data comparing the vaccine with a high-dose flu vaccine for people over 65 as the FDA suggested. At no point did FDA officials indicate the clinical trial design was inadequate, according to Dr. Stephen Hoge, Moderna's president. The agency identified no safety or efficacy concerns. In fact, Moderna's phase 3 study results from June showed the mRNA-based flu shot produced efficacy approximately 27 percent higher than Fluarix in adults 50 and older. A separate trial demonstrated superiority compared to a high-dose flu vaccine for people 65 and older. Refuse-to-file letters are exceptionally rare, issued for only 4 percent of applications according to a 2021 study of nearly 2,500 submissions. This decision appears to reflect the broader Trump administration skepticism toward mRNA technology, including the August 2024 cancellation of 22 projects worth approximately $500 million for mRNA vaccine development. mRNA flu vaccines offer significant advantages: improved efficacy, faster manufacturing that allows better matching with circulating viruses, geographic tailoring for different strains, and potential combination with Covid-19 vaccines in a single shot. The manufacturing timeline is dramatically shorter, with design decisions in May or June for August shipping compared to February strain selection for fall delivery with current technology. I urge you to investigate this decision and advocate for a fair, science-based review process that evaluates Moderna's application on its merits rather than ideology.