Moderna announced Monday that its experimental mRNA-based flu vaccine showed positive results in a late-stage clinical trial, producing a stronger immune response than an existing flu vaccine, CNBC reports.
The findings pave the way for the company to pursue regulatory approval for its standalone flu shot, and to resubmit its combination flu and Covid-19 vaccine for US authorization later this year.
The flu vaccine, known as mRNA-1010, demonstrated 26.6% greater efficacy than a standard flu vaccine among adults aged 50 and older in a Phase 3 trial involving over 40,000 participants. The vaccine showed consistent effectiveness across key influenza strains — A/H1N1, A/H3N2, and B/Victoria — and maintained its performance across age groups, health conditions, and previous vaccination status. In adults aged 65 and older, the shot was 27.4% more effective than existing options.
Moderna said the safety profile of the vaccine was in line with earlier studies. Based on these results, the company plans to seek regulatory approval for mRNA-1010 before the end of the year.
The positive trial data also allow Moderna to move forward with its previously delayed combination flu and Covid vaccine. The company had withdrawn its earlier application in May, citing a need to include efficacy data from the standalone flu shot. Moderna now intends to resubmit the application for the combination product — a strategy that could simplify seasonal vaccinations for patients and healthcare systems.
“This is a major milestone,” said Stephen Hoge, Moderna’s President and head of R&D, in an interview. “The combination jab could ease the burden on the healthcare system by consolidating appointments and improving patient uptake.”
Moderna is currently seen as a front-runner in the race to bring a combination vaccine to market, ahead of competitors such as Pfizer and Novavax. Hoge said the company anticipates regulatory decisions on both the standalone flu shot and the combination vaccine in 2025, though no specific revenue projections were shared.
The US Centers for Disease Control and Prevention (CDC) reported that the 2024–2025 flu season was the most severe in 15 years, with more than 600,000 flu-related hospitalizations. Moderna’s CEO Stéphane Bancel called the results “a significant milestone in our effort to reduce the burden of influenza in older adults,” emphasizing the growing need for more effective flu vaccines.
While the mRNA-1010 data were welcomed by investors — shares of Moderna rose nearly 3% in premarket trading — the company remains under pressure, with its stock down more than 30% year-to-date. The decline has been fueled in part by shifts in US vaccine policy under the Trump administration, including the cancellation of a federal contract related to Moderna’s bird flu vaccine development.
Moderna’s relationship with regulators remains a key factor in its future plans. Health and Human Services Secretary Robert F. Kennedy Jr., a prominent vaccine skeptic, is overseeing a significant overhaul of the US health regulatory environment, including the Food and Drug Administration (FDA). In this context, Moderna has been working closely with the agency to clarify requirements for new vaccine approvals.
“I believe, as it relates to flu, we’ve got a pretty clear path,” Hoge said.
