Moderna's stock fell due to regulatory concerns. A more important development is also under attack

The US medical regulator FDA refused to accept the application of the pharmaceutical company Moderna for approval of its new seasonal mRNA vaccine against influenza. This caused a decline in quotations, which at one point fell at the strongest pace in nine months, Bloomberg writes. The FDA's decision now threatens the advancement of a more promising development - a combination flu vaccine and Covid-19.

Moderna has received a Refusal-to-File letter from the US Food and Drug Administration (FDA), the pharma company said in a statement. The regulator pointed to the lack of an "adequate and well-controlled" study and correct comparative analysis with the existing standard of care, Moderna said.

Against this background, shares of Moderna in the course of trades on February 11 cheapened in the moment by 12.7% - up to $36.7 per share. However, by the end of trading they largely recovered their losses and ended the day down 3.5%. The FDA's action was a blow to the company, which enjoyed huge sales during the pandemic thanks to its Covid-19 vaccine, but has since struggled to bring new products to market, Bloomberg noted. Moderna, meanwhile, said it has no plans to change its financial outlook for 2026.

Moderna rejected the regulator's argument. The company emphasized that the FDA's guidance on seasonal influenza vaccines makes no mention of using a control group that reflects the "best available standard of care." The regulator's letter did not identify any specific safety or efficacy concerns regarding the vaccine, Moderna claimed. It also said the FDA's position contradicts the agency's past comments, when the regulator had no comment on the results of the third and final phase 3 trial.

The letter was personally signed by Vinay Prasad, head of the FDA's vaccine division: a rare move that indicates the agency's tougher stance on mRNA vaccines, Barron's noted. The FDA is now headed by Robert F. Kennedy, a longtime vaccine skeptic, the publication added.

The tightening regulatory stance on mRNA vaccines is "not unexpected" in the current regulatory environment, and Moderna's reliance on its vaccine business makes the company vulnerable to regulatory volatility, Citi analysts said in a note cited by Pharmaceutical Technology.

William Blair analyst Miles Minter said the Refusal-to-File letter means a "significant blow" not only to the likelihood of flu vaccine success, but also to the chances of the combined mRNA-1083 flu and Covid-19 vaccine being approved in the U.S., PT also reported.

Bloomberg Intelligence analyst Sam Fazeli called the combination vaccine "more exciting" and noted that the FDA's rejection has created uncertainty around it. The regulator must approve the flu vaccine first before Moderna can file an application for the combination vaccine, Bloomberg explained. Wall Street analysts estimate that the two vaccines, if approved, could generate about 30 percent of Moderna's revenue by 2030, the agency said.

According to Fazeli, the data on the flu vaccine is "obviously quite compelling," and the drug itself could quickly move into use in different countries. "It's a pity that politics is trumping science and common sense here," Fazeli added.

Moderna shares are up 37% since the start of 2026. This was fueled by investors' hopes related to the oncology portfolio, while the company's respiratory disease business is struggling, Barron's writes. Most analysts advise holding the company's stock: the bottom 20 have Hold ratings versus only three Buy recommendations and with four Sell and Underweight recommendations (two each Sell and Underweight), MarketWatch shows. Moderna's average target price for the stock is $37.89, down about 7% from the closing price on Feb. 11.

This article was AI-translated and verified by a human editor