A potentially groundbreaking flu vaccine, developed by Moderna using mRNA technology, faces an unexpected hurdle. The U.S. Food and Drug Administration has refused to even consider the company’s application, a decision that could significantly delay a shot designed to offer enhanced protection to older adults.
The FDA issued a “refusal-to-file” letter, stating the application lacked an “adequate and well-controlled” study. Specifically, the agency argued the study’s comparison group didn’t represent the current “best-available standard of care” for flu vaccines.
Moderna’s CEO, Stéphane Bancel, expressed surprise, emphasizing the FDA’s decision wasn’t related to safety or effectiveness. He argued the study design had been previously discussed and agreed upon with the FDA, and that hindering innovation wasn’t in the nation’s best interest.
This rare move by the FDA occurs during a period of heightened scrutiny regarding vaccine approvals. Health Secretary Robert F. Kennedy Jr., a known critic of mRNA vaccines, has recently altered COVID-19 vaccine recommendations and restructured federal vaccine advisory panels.
Kennedy’s actions include canceling substantial mRNA vaccine contracts and removing the COVID-19 vaccine from the CDC’s routine immunization schedule for healthy children and pregnant women, signaling a shift in federal vaccine policy.
The core of the FDA’s objection centers on Moderna’s choice of a standard-dose flu vaccine as the comparison in its Phase 3 trial. The agency now contends a higher-dose vaccine should have been used, despite earlier guidance suggesting a standard-dose comparator would be acceptable.
Moderna maintains the FDA didn’t raise these concerns during the trial’s planning stages or after the study protocol was submitted. The company asserts it addressed all requests for additional data, yet the application was still rejected.
Prior to submitting the application, Moderna held a meeting with the FDA, where concerns about the comparator were raised, but the agency indicated the data would be a “significant issue” during review, not grounds for outright refusal. Moderna was not informed of the severity of the issue.
While the FDA review is stalled in the U.S., Moderna is continuing regulatory processes in other countries, including the European Union, Canada, and Australia, hoping for a different outcome elsewhere.
Moderna has requested an urgent meeting with the FDA to understand the reasoning behind the refusal and to determine a path forward, aiming to ensure seniors and those with underlying health conditions have access to this potentially innovative vaccine.
