The FDA has agreed to formally review Moderna’s biologics license application (BLA) for its investigational mRNA seasonal influenza vaccine, mRNA-1010, reversing an earlier refusal-to-file decision that halted the regulatory process.
In a press release announcing the development, Moderna said the FDA will initiate review of the submission following a Type A meeting between the company and the agency. Under the amended filing strategy, Moderna is seeking full approval for adults 50 to 64 years of age and accelerated approval for adults 65 years and older, with a Prescription Drug User Fee Act target date of August 5, 2026.
“We appreciate the FDA’s engagement in a constructive Type A meeting and its agreement to advance our application for review,” said Moderna CEO Stéphane Bancel, MEng, MBA, in the statement. “We look forward to continuing to work with the agency through the review process and potentially offering our seasonal influenza vaccine in the United States to provide another option for protection against flu.”
A Quick Reversal
The reversal comes less than two weeks after the FDA declined to accept the BLA for review, citing concerns related to the comparator vaccine used in pivotal trials involving older adults.
Paul Offit, MD, the director of the Vaccine Education Center at Children’s Hospital of Philadelphia, said he was not surprised by the reversal itself, but only by its speed. “They could have waited the usual 30 days to meet with the company again after a Refusal to File, but they made the decision immediately. I had predicted to a friend that I thought that Vinay Prasad [MD, MPH, the director of the FDA’s Center for Biologics Evaluation and Research] would change his mind at the meeting, but I was wrong about how long it would take to happen.”
The FDA defended its original decision to refuse the review when officials spoke to the press on Feb. 11. “The FDA rejected Moderna’s application for filing because the company refused to follow very clear FDA guidance from 2024 to test its product in a clinical trial against a CDC-recommended flu vaccine to compare safety and efficacy,” said HHS spokesperson Andrew Nixon.
When questioned about media reports stating that David Kaslow, MD, the head of the vaccine office, had written a memo explaining why the FDA should go ahead with the review, a senior agency official suggested that “a disgruntled person” was “getting disproportionate coverage by reaching out and telling their version of the story.”
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Did Public Criticism Play a Role?
The about-face suggests that there was more to the story, Dr. Offit said. “It became clear very early that this was Prasad’s decision and not that of FDA scientific staff. And I just didn’t get the sense that [FDA director] Marty Makary [MD, MPH,] was quickly standing up in his defense either.”
Public criticism may have played a role in the swift turnaround: On Feb. 11, the Wall Street Journal’s editorial board printed an opinion piece titled “Vinay Prasad’s Vaccine Kill Shot,” which began, “It’s hard to recall a regulator who has done as much damage to medical innovation in as little time as Vinay Prasad. In his latest drive-by shooting, the leader of the Food and Drug Administration’s vaccine division rejected Moderna’s mRNA flu vaccine without even a cursory review. This is arbitrary government at its worst.”
Good Data So Far
Looking ahead, Dr. Offit said he expects the review to move quickly. “Certainly the data, as I understand it, look good,” he said. “The mRNA vaccines are 29% more effective at preventing influenza-like illness, and 45%+ better at protecting against influenza hospitalization. It’s a very good technology that unfortunately has suffered these political slings and arrows.”
If approved, mRNA-1010 would represent the first mRNA-based seasonal influenza vaccine authorized in the United States.
Dr. Offit reported no relevant financial disclosures. He is a co-inventor of a vaccine for rotavirus.