The US Food and Drug Administration (FDA) will now review Moderna’s application for an mRNA-based influenza vaccine for adults aged 50 and older, reversing a previous decision to decline review just one week prior. The agency had initially refused to review the application, citing concerns about the design of Moderna’s phase 3 clinical trial.
Moderna announced today that it has proposed a revised regulatory approach to the FDA for its investigational seasonal influenza vaccine candidate, mRNA-1010. The company is seeking full approval for individuals between 50 and 64 years of age, and accelerated approval for those 65 and older. The accelerated approval pathway for older adults is contingent upon a post-marketing study to further evaluate the vaccine’s performance in that demographic.
The FDA has set a target review date of August 5, 2026, according to Moderna. “We appreciate the FDA’s engagement in a constructive Type A meeting and its agreement to advance our application for review,” said Stephane Bancel, Moderna’s CEO. “Pending FDA approval, we look forward to making our flu vaccine available later this year so that America’s seniors have access to a new option to protect themselves against flu.”
The initial rejection stemmed from the FDA’s assessment that Moderna’s phase 3 study was not “adequate and well-controlled.” A key point of contention was the use of a standard-dose flu shot as a comparator for individuals aged 65 and older, rather than the high-dose flu vaccines typically administered to that population. Moderna maintains that the study design had previously been approved by the FDA’s Center for Biologics Evaluation and Research (CBER), and Bancel stated that the agency had not raised concerns about the vaccine’s safety or efficacy.
The reversal comes amid broader shifts in the FDA’s approach to mRNA vaccine contracts and a reported skepticism towards the technology from Health and Human Services Secretary Robert F. Kennedy Jr. Since last August, Kennedy has overseen a $500 million reduction in mRNA contract funding, reflecting his long-held opposition to mRNA vaccines, including those developed during the COVID-19 pandemic.
The FDA’s initial refusal to review the Moderna application sent ripples through the vaccine market, with reports indicating that vaccine manufacturers, including Moderna, are scaling back operations and reducing staff in anticipation of a challenging business environment under the current administration.
Experts remain puzzled by the FDA’s change of course. “We don’t have any idea why they reversed course,” said Michael Osterholm, director of the University of Minnesota’s Center for Infectious Disease Research and Policy. “That’s part of the problem.” Osterholm emphasized the need for consistent regulatory policies to foster confidence among vaccine developers. “They need to understand what is needed for approval, and how it would be supported after approval. Without that we will see a rapidly changing vaccine landscape. This current situation demonstrates how out of control we are in the FDA’s consideration and review of currently licensed vaccines and potential new vaccines.”
Robert H. Hopkins Jr., MD, medical director of the National Foundation for Infectious Diseases, expressed cautious optimism about the FDA’s decision. “It is hard to assess whether this is an indication of changes in agency leadership’s approach to new vaccine applications or not; but I am hopeful that it does,” Hopkins said. “The availability of another option for influenza vaccination, particularly if it is using a technology which allows more rapid changes in the vaccine to adapt to strain changes than is an option with current influenza vaccines, will potentially be a major step forward in efforts to protect the health of individuals from severe influenza.”
