In adults 50 and older, Moderna’s flu shot was more than 26% better than an unspecified commercial vaccine. In May, the company pulled its application for a combo flu/COVID-19 shot, saying it would refile following data from this Phase III trial.
Moderna’s mRNA vaccine for seasonal influenza, mRNA-1010, outperformed a currently available shot in older adults in a Phase III trial, paving the way not only toward a regulatory submission but also potentially to a refiling for the company’s combination COVID-19 vaccine.
According to a readout early Monday, mRNA-1010 was 26.6% more effective at preventing influenza in adults aged 50 years and older than a currently licensed, standard-dose seasonal flu vaccine. The company did not specify which shot mRNA-1010 was being compared to.
In a statement alongside the readout, Moderna CEO Stéphane Bancel called mRNA-1010’s data “strong,” noting that the results “pave the way for COVID-19 combination vaccines.”
In May, without providing an explicit reason for the decision, the company voluntarily pulled its Biologics License Application for mRNA-1083, its combo shot for flu and COVID-19. At the time, Moderna said that it would refile the submission “after vaccine efficacy data from the ongoing Phase 3 trial of its investigational seasonal influenza vaccine, mRNA-1010, are available.”
In an email to BioSpace, a company spokesperson confirmed that those filing plans are still in place and that Moderna will share data with regulators “in due course,” but it “cannot share specifics on timelines right now.”
The flu vaccine was even more effective in other populations. In the subgroup of seniors 65 years and above, mRNA-1010 beat the currently licensed vaccine by 27.4%. More than 40,000 individuals across 11 countries participated in the late-stage study, with a median follow-up of six months.
Disaggregating mRNA-1010’s relative vaccine efficacy showed similar findings: Moderna’s shot was 29.6% better than the comparator vaccine at eliciting protection against the A/H1N1 strain, 22.2% against A/H3N2 and 29.1% against B/Victoria. These are the strains being included in the updated 2025-2026 vaccines for the upcoming influenza season.
As for safety, mRNA-1010 appeared to be well-tolerated overall. Most of the adverse events were mild. Pain at the injection site was the most common side effect, alongside fatigue, headaches and myalgia. Moderna on Monday said it will present these findings at a future scientific congress and will “engage with regulators” regarding submissions for mRNA-1010.
Moderna stock was up about 5% in premarket trading Monday.
Moderna’s data release comes as the broader vaccine space has been battered by high-level headwinds in recent weeks. Earlier this month, Health Secretary Robert F. Kennedy Jr. emptied the CDC’s vaccine advisory committee only to later restock it with fewer members, many of whom are known vaccine critics.
The new panel convened last week and was expected to decide on mRNA COVID-19 vaccine guidelines and Moderna’s RSV vaccine mRESVIA—but decided to skip the vote for both. The discussions instead focused on the safety of mRNA technology.
“New ACIP [Advisory Committee on Immunization Practices] has a bone to pick with mRNA vaccines,” Truist Securities analysts wrote in a June 26 note to investors. “Going forward, we expect ACIP to continue picking on safety issues as a backchannel to anti-vax agendas.”
