Moderna Inc. said its experimental flu shot met its goal in a late-stage trial, clearing the path for its broader strategy of selling combination vaccines.
The shot’s efficacy was 27 percent higher than a licensed influenza vaccine in adults 50 years and older, the company said in a statement Monday. The trial enrolled more than 40,000 adults across 11 countries.
The results set the stage for Cambridge-based Moderna to offer a single shot that protects against COVID and flu. US regulators recently told the company that it needed to produce flu vaccine efficacy data — and not just data on the immune response — delaying a potential approval for a combination shot until next year.
Shares rose as much as 5.8 percent at the start of normal trading on Monday in New York.
Moderna believes packaging the two immunizations together will lead to higher uptake of COVID vaccines. Nearly half of American adults get an annual flu shot, while only about 23 percent got the latest COVID vaccine.
Moderna’s flu shot, which uses mRNA technology, also could contribute to a longtime public health goal: a better standalone flu shot. That mission has only become more urgent after the United States just experienced by some measures its worst flu season in 15 years. This year’s flu vaccines were 56 percent effective.
The company will seek approval for both its standalone flu shot and its COVID-flu combination vaccine, said Jacqueline Miller, Moderna’s chief medical officer.
The flu vaccine “is such a central component of our strategy,” Miller said in an interview, adding that a combination COVID-flu shot could entice someone who “is put off by getting two injections at once.”
Moderna’s technology can make vaccines faster than the standard method, which requires growing the live virus in chicken eggs then inactivating it. That could make it easier to match the vaccine to the dominant strains that are circulating each season.
The results are a rare bright spot for a company that has struggled with the decline of its COVID business and more recently, the new leadership of Health and Human Services Secretary Robert F. Kennedy Jr., a vaccine critic. Under Kennedy, US health officials have rolled back long-standing recommendations around COVID shots for children and pregnant women, approved Moderna’s updated COVID shot for a narrower group of people, and terminated the company’s contract to develop bird flu vaccines.
After the bird flu vaccine contract cancellation, the company has been “actively seeking other funding sources” and is considering advancing the vaccine on its own, Miller said.
Moderna’s flu program has been on a tumultuous path. Over two years ago, the company’s standalone flu vaccine yielded mixed results. Several months later, the company reported that a reformulated version produced a stronger immune response. Last year, the company said it would focus its resources on seeking approval for a flu and COVID combination vaccine because it said it would have a bigger impact.