Regulatory & Policy

Pfizer and BioNTech's XFG-adapted Comirnaty given FDA clearance for fall 2026 rollout

Edited by Robert McTiernan··2 min read
Pfizer and BioNTech's XFG-adapted Comirnaty given FDA clearance for fall 2026 rollout

The US FDA has approved a supplemental Biologics License Application (sBLA) for Comirnaty XFG (COVID-19 vaccine, mRNA), the 2026–2027 XFG-adapted formulation developed by Pfizer and BioNTech SE (Nasdaq: BNTX), for adults aged 65 and older and for individuals aged 5 through 64 with at least one underlying condition placing them at high risk for severe COVID-19 outcomes. The XFG strain was selected based on FDA guidance as the preferred composition for US COVID-19 vaccines beginning in fall 2026.

The approval covers active immunization against COVID-19. The sBLA was supported by the cumulative clinical, non-clinical, and real-world evidence base for Comirnaty, supplemented by manufacturing, quality, and non-clinical immunogenicity data specific to the XFG-adapted formula. The companies said the vaccine generated immune responses against multiple currently circulating SARS-CoV-2 lineages, including XFG, XFG.1.1, NB.1.8.1, PQ.17, and PQ.2.8.1. Shipping began immediately following approval.

The regulatory basis mirrors the strain-update pathway used for annual influenza vaccine reformulation: rather than requiring new large-scale efficacy trials, the sBLA relied on immunobridging and manufacturing comparability data alongside the existing Comirnaty evidence package. No new clinical trial identifier was cited by the companies for this specific formulation update; supporting immunogenicity data were presented at the May 28, 2026 VRBPAC meeting.

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Comirnaty XFG uses the same mRNA-LNP platform as earlier Comirnaty formulations, with the mRNA sequence updated to encode the spike protein of the XFG variant. The LNP delivery platform underlying Comirnaty is the subject of ongoing patent litigation: Arbutus Biopharma and Genevant Sciences have escalated intellectual property claims against Pfizer and BioNTech across North America and the EU.

The approval comes as the US COVID-19 vaccine market shifts away from the broad population approach used earlier in the pandemic toward a more targeted, risk-based model. Comirnaty XFG is approved for adults aged 65 and older and for people aged 5–64 with underlying conditions that put them at increased risk of severe COVID-19, narrowing the addressable seasonal market for Pfizer and BioNTech. More than five billion doses of Comirnaty have been distributed globally to date, the companies said.

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