An FDA advisory committee voted unanimously (9-0) on June 18 to find the mRNA-based investigational seasonal influenza vaccine mRNA-1010 (Moderna) safe and efficacious, with benefit outweighing risk in preventing influenza in adults 50 years and older.1
The finding by the Vaccines and Related Biological Products Advisory Committee (VRBPAC) does not obligate the FDA to approve the product, but it is required to take action on the application by August 5 to comply with the Prescription Drug User Fee Act (PDUFA).
The unanimous recommendation by the committee is a departure from resistance to the technology in the Department of Health and Human Services (HHS) marked by initial refusal of the FDA to review the application,2 and cancellation of contracts3 that supported development of mRNA technology.
The evidence reviewed by the committee in determining efficacy and safety included the pivotal phase 3, double-blind, active-controlled, multi-national trial recently published in the New England Journal of Medicine.4
Evidence of Efficacy and Safety
Isbel Leroux-Roels, MD, Center for Vaccinology, Ghent University, Ghent, Belgium, and colleagues conducted the trial with over 40,000 participants 50 years of age or older. Participants were randomized to receive either the mRNA-1010 or a licensed standard-dose inactivated comparator vaccine prior to the 2024-25 influenza season.
The trivalent formulation of mRNA-1010 contained mRNAs encoding surface hemagglutinin antigens of three WHO-recommended 2024-2025 cell- or recombinant-based influenza strains. The 37.5mcg intramuscular dose comprised 12.5mcg of each strain.The preferred comparator was a standard dose trivalent vaccine, but a quadrivalent, high dose or adjuvanted vaccine was used depending on availability and local requirement.
The primary measure of efficacy was a first episode of protocol-defined, RT-PCR assay confirmed influenza illness caused by any influenza A or B strain beginning at least 14 days after the injection, through the end of the influenza season.Active surveillance included monitoring twice-weekly e-diary prompts to report respiratory symptoms.Safety and reactogenicity were assessed from adverse events from e-diary entry and unsolicited reports.
There were 968 confirmed cases of influenza across the three circulating strains.The investigators reported that the mRNA-1010 met pre-specified criterion of higher-level superiority relative to the comparator, with approximately 27% fewer cases of illness over the median 181 day follow-up (2.0% of the mRNA-1010 group vs 2.8% of the comparator group). An exploratory analysis found that medically attended influenza-associated outcomes across all health care settings occurred in 80 recipients of mRNA-1010 and 120 receiving the comparator.
What You Need to Know
Vaccines and Related Biological Products Advisory Committee (VRBPAC) voted 9-0 that the benefits of mRNA-1010 outweigh its risks for preventing seasonal influenza in adults aged 50 years and older, supporting the vaccine ahead of the FDA’s August 5 PDUFA decision.
In a trial of more than 40,000 adults aged 50 and older, mRNA-1010 reduced laboratory-confirmed influenza cases by approximately 27% compared with licensed influenza vaccines, with 2.0% of recipients developing influenza versus 2.8% in the comparator group.
Recipients of mRNA-1010 experienced higher rates of injection-site pain, fatigue, headache, and myalgia than those receiving comparator vaccines, although serious adverse event rates were low and similar between groups (2.2% vs 1.9%), highlighting a benefit-risk tradeoff that clinicians and patients may need to consider.
The mRNA-100 was, however, associated with more frequent adverse reactions than the comparator: injection-site pain in 65.8% vs 29.8%, fatigue in 45.1% vs 20.3%, headache in 37.8% vs 18.0%, and myalgia in 35.4% vs 11.6%. Serious adverse events were reported in 2.2% of recipients of mRNA-1010 vs 1.9% with the comparator vaccine.
The investigators noted that while mRNA-1010 demonstrated superior efficacy and that serious adverse events were infrequent and similar in the two groups, the greater frequency of solicited adverse reactions with mRNA-1010 will warrant consideration in selecting between agents.
The more common adverse events with the investigational vaccine, Leroux-Roels and colleagues indicate, "suggests a need for balancing assessment of temporary vaccine-induced reactogenicity events with the magnitude of protection against influenza."
References
1. Moderna. News Release. Moderna announces FDA advisory committee votes unanimously in favor of the benefit-risk profile of mRNA-1010, an investigational seasonal influenza vaccine. 2026, June 18. https://feeds.issuerdirect.com/news-release.html?newsid=5170330895753287&symbol=MRNA . Accessed June 18, 2026.
2. Moderna. News Release. Moderna Receives Refusal-to-File Letter from the US Food and Drug Administration for its investigational seasonal influenza vaccine, mRNA-1010.
4. Leroux-Roels I, Huang G, Ferguson M, et al. Efficacy and safety of an mRNA seasonal influenza vaccine in adults. N Engl J Med. 2026; 394:1803-1814,
