The Food and Drug Administration’s Vaccines and Related Biological Products Advisory Committee voted 9-0 on June 18, 2026, that the benefits of Moderna’s mFLUSIVA (mRNA-1010) outweigh its risks for adults aged 50 and older — clearing the final advisory hurdle before the agency’s August 5 PDUFA decision. The unanimous vote is significant, but it is a recommendation, not an approval.
A Split Approval Pathway
The committee’s favorable recommendation covers two distinct regulatory tracks. For adults aged 50 to 64, Moderna is seeking traditional approval on the basis of clinical efficacy data from the P304 pivotal trial published in the New England Journal of Medicine. For adults 65 and older, the company is pursuing accelerated approval, supported by immunogenicity data rather than direct clinical-efficacy measurements — a distinction that will shape product labeling and the post-market commitments required of Moderna if the 65+ indication is granted.
The P304 trial enrolled adults 50 and older and compared mFLUSIVA against a standard-dose licensed quadrivalent influenza vaccine (Fluarix or equivalent) — not a high-dose or recombinant product. Relative vaccine effectiveness against PCR-confirmed influenza-like illness was 26.6% overall, with higher point estimates against A/H1N1 (47.9%) and A/H3N2 (29.6%) strains than against B lineages (22.2%). Against symptomatic influenza illness across all strains, rVE was 29.1%. A separate immunogenicity analysis compared mFLUSIVA to Fluzone High-Dose in adults 65 and older, providing the immunobridging data underpinning the accelerated approval pathway for that cohort.
The comparator matters. The 26.6% rVE reflects improvement over a standard-dose seasonal influenza vaccine, not over a high-dose or recombinant product. VRBPAC panelists noted they would have preferred head-to-head clinical efficacy data against a high-dose comparator for the 65+ population; the immunogenicity bridge was accepted as a surrogate for accelerated approval but leaves clinical efficacy against the strongest available alternatives unconfirmed.
Background: RTF and Resolution
The FDA had previously issued a refuse-to-file letter for the mFLUSIVA application, citing deficiencies in the submission. Moderna subsequently filed additional analyses that addressed those concerns; the agency accepted the resubmission and scheduled the VRBPAC review. The June 18 meeting was the first time panelists formally evaluated the complete data package in a public forum.
Panelists raised questions about the immunobridging approach used to support the accelerated-approval pathway in the 65+ cohort, and noted that head-to-head efficacy data against the high-dose comparator using a clinical (rather than immunogenicity) endpoint would strengthen confidence in that age group.
What Comes Next
The FDA is not obligated to follow advisory committee recommendations, but it does so in the large majority of cases. The PDUFA target date of August 5, 2026, falls immediately before peak vaccination season for Northern Hemisphere influenza, creating a narrow window for label finalization, manufacturing scale-up, and distribution if the product is approved. Moderna has not disclosed a commercial launch timeline or pricing.
Moderna Inc. P304 Phase 3 trial (mRNA-1010): N Engl J Med. 2026; doi:10.1056/NEJMoa2516491. VRBPAC meeting June 18, 2026. PDUFA action date August 5, 2026.
Correction (June 21, 2026): An earlier version of this article stated the P304 trial compared mFLUSIVA against “a high-dose recombinant quadrivalent influenza vaccine.” The P304 efficacy trial used a standard-dose licensed quadrivalent influenza vaccine (Fluarix or equivalent) as its comparator; the 26.6% rVE reflects improvement over a standard-dose baseline. A separate immunogenicity analysis compared mFLUSIVA to Fluzone High-Dose in adults 65 and older, supporting the accelerated approval pathway for that cohort. The front-matter claim, body paragraph, and callout have been corrected.