Moderna's mRNA Flu Shot Gets Its FDA Moment

FDA reviews Moderna's mRNA flu vaccine June 18, with an August 5 decision due, as cancer trial data shows durable 49% risk reduction

17 Jun 2026

June 18 marks a pivotal day for Moderna. FDA advisors convene to review mRNA-1018, the company's experimental influenza vaccine, with a formal approval decision expected August 5, 2026. A green light would make it the first mRNA-based flu vaccine cleared for American consumers, upending a multibillion-dollar market long built on egg-based manufacturing.

Separate clinical news is adding momentum. Five-year follow-up data from the Phase 2b KEYNOTE-942 trial shows that intismeran, the personalized cancer vaccine developed with Merck, is holding its ground. In a January 2026 update, Moderna and Merck confirmed the combination of intismeran and Keytruda reduced the risk of recurrence or death by 49% in resected high-risk melanoma patients compared to Keytruda alone. That figure matches what researchers observed at three years, meaning the benefit is not fading.

Durability matters enormously in oncology. A treatment that holds its efficacy over five years changes what clinicians can realistically promise their patients, and it strengthens the case for standard-of-care shifts that shorter follow-up windows simply could not support. Regulatory filings for intismeran are advancing alongside this expanding body of evidence.

Both developments point in the same direction: mRNA platforms are moving well past their pandemic origins, into genuinely new therapeutic territory. August 5 will tell investors, health systems, and supply planners whether the technology can claim a commercial foothold in influenza, and the answer will ripple through every mRNA product currently working its way through regulatory review.