CAMBRIDGE, Mass., May 6, 2026
Moderna announced the publication of pivotal Phase 3 clinical safety and efficacy data for its investigational seasonal influenza vaccine mRNA-1010 in the prestigious New England Journal of Medicine (NEJM), marking a significant milestone in the company’s efforts to expand its mRNA vaccine platform beyond COVID-19. The peer-reviewed publication detailed results from the global P304 Phase 3 trial, which evaluated the relative vaccine efficacy (rVE) of mRNA-1010 compared with a licensed standard-dose seasonal influenza vaccine in adults aged 50 years and older. According to the published findings, mRNA-1010 achieved the study’s most stringent predefined superiority endpoint, demonstrating a 26.6% relative vaccine efficacy advantage over the comparator vaccine across the overall study population. The data further strengthens Moderna’s ongoing regulatory submissions currently under review in the United States, Europe, Canada, and Australia, with potential approvals expected to begin in 2026.
Phase 3 Trial Demonstrates Strong Protection Across Influenza Strains and High-Risk Populations
The Phase 3 P304 study represents one of Moderna’s most important late-stage vaccine development programs outside of COVID-19 and involved adults aged 50 years and older, a population particularly vulnerable to severe influenza complications. Published data showed that mRNA-1010 delivered strong efficacy across all major influenza strains included in the vaccine formulation. Specifically, the vaccine demonstrated a relative vaccine efficacy of 29.6% against influenza A/H1N1, 22.2% against A/H3N2, and 29.1% against B/Victoria lineage viruses compared with the licensed standard-dose flu vaccine. Importantly, subgroup analyses revealed consistently favorable efficacy outcomes across multiple patient populations, including older adults, individuals with underlying risk factors, and participants with previous influenza vaccination history.
Among adults aged 65 years and older, a demographic that often experiences reduced immune responses to traditional influenza vaccines, mRNA-1010 achieved a notable 27.4% relative vaccine efficacy advantage, highlighting the vaccine’s potential to improve protection in one of the highest-risk patient groups. Moderna stated that the vaccine’s mRNA platform may enable more precise matching to circulating viral strains, potentially overcoming one of the longstanding limitations associated with conventional egg-based flu vaccine manufacturing technologies. The company believes this flexibility could help improve vaccine effectiveness during severe influenza seasons when viral strain mismatches contribute to reduced protection and increased hospitalization rates.
mRNA Technology Expands Beyond COVID-19 Into Seasonal Influenza Prevention
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The publication also reinforces Moderna’s broader strategic push to establish mRNA-based vaccines as a next-generation platform for infectious disease prevention. Since the global success of its COVID-19 vaccine, the company has rapidly expanded its clinical pipeline into respiratory viruses, oncology, rare diseases, and combination vaccines. mRNA-1010 represents one of the company’s most commercially significant pipeline programs due to the substantial global burden associated with seasonal influenza. According to the U.S. Centers for Disease Control and Prevention (CDC), the 2024-2025 influenza season resulted in more than 545,000 flu-related hospitalizations in the United States, reaching the highest level of influenza-related outpatient visits and hospitalizations in over 15 years.
Moderna Chief Executive Officer Stéphane Bancel stated that publication in the New England Journal of Medicine validates the strength of the clinical evidence supporting regulatory review activities currently underway across multiple global markets. Regulatory filings for mRNA-1010 have already been accepted for review in the U.S., Europe, Canada, and Australia, while additional international submissions are planned throughout 2026. The U.S. Food and Drug Administration (FDA) has assigned a Prescription Drug User Fee Act (PDUFA) target action date of August 5, 2026, positioning the vaccine as a potential near-term entrant into the competitive seasonal influenza vaccine market.
Regulatory Momentum Strengthens Moderna’s Respiratory Vaccine Portfolio
The progress of mRNA-1010 comes at a critical time for Moderna as the company works to diversify revenue streams beyond COVID-19 vaccine sales while leveraging its established mRNA infrastructure and manufacturing capabilities. Analysts view the seasonal influenza market as a major commercial opportunity, particularly if mRNA-based vaccines can consistently demonstrate superior efficacy over existing standard-dose flu vaccines. The positive Phase 3 data may also support future development of combination respiratory vaccines that target influenza, COVID-19, and respiratory syncytial virus (RSV) within a single formulation, an area where Moderna continues to invest aggressively.
With regulatory decisions expected beginning in 2026, mRNA-1010 could become one of the first commercially approved mRNA-based influenza vaccines globally. The publication in NEJM significantly enhances the scientific credibility of the program and may strengthen physician and regulatory confidence in the broader use of mRNA technologies for routine infectious disease prevention. As seasonal influenza continues to create substantial healthcare burdens worldwide, Moderna’s investigational vaccine could represent an important advancement in improving vaccine effectiveness for older adults and other vulnerable populations.
Source: Moderna press release
