Moderna says the FDA will consider its new flu shot after resolving a public dispute

The Food and Drug Administration has reversed course and will now consider Moderna’s application for its new flu vaccine, resolving a dispute that had temporarily blocked the biotech company’s innovative shot from regulatory review.

Moderna announced the development Wednesday, just a week after revealing that the FDA’s vaccine chief had issued a “refusal to file” letter for the mRNA-based influenza vaccine. The company’s shares rose more than 5% in morning trading following the announcement.

At the center of the dispute was Moderna’s 40,000-person clinical trial, which demonstrated that its mRNA flu vaccine showed greater effectiveness in adults aged 50 and older compared to one of the standard flu vaccines currently on the market. However, FDA vaccine director Dr. Vinay Prasad had criticized the trial for not including another brand specifically recommended for people 65 and older as a comparison.

Moderna publicly challenged this assessment, stating that while the FDA had initially recommended including the high-dose comparator, the agency ultimately approved the study’s design. The company also noted it had shared additional comparison data from a separate trial that used a high-dose shot intended for older adults. According to Moderna, the FDA did not identify any safety concerns with its vaccine candidate.

As a compromise solution, Moderna announced Wednesday it is now seeking full approval for the vaccine’s use in adults aged 50 to 64 and accelerated approval for those 65 and older. This approach would include conducting an additional study once the shot reaches the market. The FDA has set a target decision date of August 5, and Moderna expressed hope that the vaccine could become available later this year.

The vaccine represents a significant potential advancement in influenza prevention, as it employs the same Nobel Prize-winning mRNA technology used in Moderna’s successful COVID-19 vaccine. Unlike traditional flu vaccines, which are typically grown in eggs or cells and can take months to produce, mRNA vaccines can be manufactured more rapidly and potentially adjusted more easily to match circulating virus strains.

Moderna has also submitted applications for the vaccine’s approval in Europe, Canada, and Australia, positioning the product for potential global distribution if approved.

The public disagreement between Moderna and the FDA is unusual in the typically behind-closed-doors regulatory process and comes amid what observers note is heightened scrutiny of vaccines under Health Secretary Robert F. Kennedy Jr., particularly those utilizing mRNA technology. Kennedy, who took office as part of the Trump administration, has been critical of this technology both before and after becoming the nation’s top health official.

Industry analysts point out that the FDA’s approach to vaccines has shifted noticeably in recent months. Officials working under Kennedy’s leadership have scaled back recommendations for COVID-19 vaccines, added additional warnings to the two primary COVID vaccines that use mRNA technology, and removed critics of the administration’s pharmaceutical policies from an FDA advisory panel.

The resolution of this dispute represents a significant development for Moderna, which has been working to diversify its product portfolio beyond COVID-19 vaccines. The company has invested heavily in applying its mRNA platform to other infectious diseases, including influenza and respiratory syncytial virus (RSV).

For consumers, the potential approval of Moderna’s flu vaccine could eventually provide another option for seasonal protection against influenza, which causes hundreds of thousands of hospitalizations and tens of thousands of deaths in the United States annually.

The FDA’s final decision, expected by early August, will determine whether this new approach to flu vaccination will reach the market for the upcoming influenza season.