The US Food and Drug Administration (FDA) has approved mFLUSIVA (mRNA-1010), Moderna's mRNA-based seasonal influenza vaccine, for use in all adults ≥ 50 years of age, granting full approval in adults aged 50 to 64 years and accelerated approval in adults aged ≥ 65 years.¹
The approval, announced on August 5, 2026, marks the first mRNA-based influenza vaccine cleared in the United States and follows a unanimous recommendation from the FDA's Vaccines and Related Biological Products Advisory Committee (VRBPAC).¹ mFLUSIVA joins Spikevax, mRESVIA, and mNEXSPIKE in Moderna's US respiratory vaccine lineup.¹
"The FDA approval of mFLUSIVA, our fourth approved product in the United States and the first mRNA-based flu vaccine, demonstrates the continued strength and versatility of our mRNA platform," said Stéphane Bancel, chief executive officer of Moderna, in a statement¹ "Flu remains a significant public health challenge, and mFLUSIVA provides an important new option for America's seniors."
mFLUSIVA Efficacy and Safety in the FLUENT Phase 3 Trial
Full approval in adults 50 to 64 years rests on results from the randomized, double-blind, active-controlled Phase 3 FLUENT trial (NCT06602024), which enrolled 40,805 adults aged ≥ 50 years across 301 sites in 11 countries.² Participants received a single intramuscular dose of trivalent mRNA-1010 (37.5 μg) or a licensed standard-dose comparator, with a median follow-up of 181 days.² RT-PCR-confirmed, protocol-defined influenza-like illness occurred in 2% of mRNA-1010 recipients compared with 2.8% of recipients of the standard-dose comparator.²
This difference corresponded to a relative vaccine efficacy of 26.6% (95% confidence interval [CI] 16.7 to 35.4), meeting prespecified thresholds for noninferiority, superiority, and higher-level superiority (P <.001).² Among the 19,260 participants aged ≥ 65 years, relative vaccine efficacy was 27.4% (95% CI, 12.1 to 40.0).²
Approval in adults aged ≥ 65 years followed a separate randomized, observer-blind, active-controlled trial (NCT05827978) enrolling 2992 US adults in this age group.¹ This study compared immunogenicity of mFLUSIVA against a high-dose inactivated influenza vaccine comparator, and the accelerated approval designation for adults aged ≥ 65 years rests on this immunogenicity bridge rather than confirmed clinical efficacy.¹ Descriptive rVE data from the FLUENT trial provide additional support in this population.
mFLUSIVA Safety Profile and Regulatory Pathway
Moderna reported an acceptable safety profile across the phase 3 program, with no new safety signals identified and results consistent with previously reported mFLUSIVA studies.¹ Injection site reactions included pain, tenderness, swelling of lymph nodes in the injected arm, induration, and redness.¹ Systemic reactions included fatigue, headache, muscle pain, joint pain, chills, nausea or vomiting, and fever.¹ Severe allergic reactions were rare but can occur, typically within minutes to 1 hour after vaccination, and mFLUSIVA carries a contraindication in individuals with a history of severe allergic reaction to any vaccine component.¹
The accelerated approval pathway for adults aged ≥ 65 years is contingent on verification of clinical benefit in a confirmatory postmarketing trial. Beyond the US, mRNA-1010 has been accepted for regulatory review in the European Union, Canada, and Australia, with additional country submissions planned during 2026.¹
Moderna expects mFLUSIVA to reach select US retailers within the coming weeks, positioning the vaccine for the 2026-2027 respiratory virus season alongside Spikevax, mRESVIA, and mNEXSPIKE.¹ The FLUENT trial's descriptive rVE analysis and the ongoing postmarketing study in older adults will shape how the vaccine's efficacy data mature over the coming seasons.²
References
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(18):1803-1813. doi:10.1056/NEJMoa2516491
