Moderna has hit a major snag because the US Food and Drug Administration (FDA) turned down its request to look at its application for the first mRNA-based seasonal flu vaccine. The company’s February 3 letter explains the decision, saying that there wasn’t a “adequate and well-controlled” trial because the control group didn’t get the best standard care available at the time of the study. There were no problems with the vaccine’s safety or effectiveness data.
In its phase 3 trial, which included more than 40,000 adults over the age of 50, Moderna’s mRNA-1010 vaccine was about 27% more effective than the Fluarix vaccine. A different study that looked at people 65 and older who got a high-dose flu vaccine showed that it worked better at boosting the immune system. The mRNA platform promises to make vaccines faster and better at matching strains as flu season gets closer. This could make vaccines more effective against viruses that are already out there.
This refusal is in line with the Trump administration’s broader scrutiny of mRNA vaccines, which has included ending contracts like the $590 million HHS deal for Moderna’s bird flu vaccine. Moderna plans to address the FDA’s concerns and refile. Its flu vaccine is also being reviewed in the EU, Canada, and Australia, where it could be approved by the end of 2026. After the news, the company’s stock price dropped before the market opened.
