Moderna's Vaccine Goes Flu Steam Ahead

Research evidence excerpt

Moderna's Vaccine Goes Flu Steam Ahead

Pharmaceuticals (Major) & Large Cap Biotechnology

Biotechnology-Large Cap - Market Weight

Moderna's Vaccine Goes Flu Steam Ahead June 18, 2026

Moderna (MRNA)

The Wolfe Byte

FDA AdCom votes unanimous YES that benefits of MRNA's mFlusiva outweigh risks for ages 50-64 & 65+. Despite

trial design, we'd agree data warrants approval. All these things considered, we see commercial opportunity for

mFlusiva as incremental (Wolfe peak $338M, cons $734M).

A quick refresher on how we got here. Moderna (MRNA) announced positive results from its phase 3 flu vaccine efficacy

trial, P304, nearly a year ago today (our recap of the topline here) where it showed a rVE (relative vaccine efficacy) of

26.6% in the overall population and a higher rVE of 27.4% among the age 65+ subgroup. Then last February, MRNA

informed us that it received a Refusal-to-File letter from FDA on the basis that the standard-dose flu vaccine it used

as the comparator arm was not the best available standard of care; this was despite previous alignment with CBER

and no objections at the time of FDA submission (our original thoughts here). Following a constructive Type A meeting,

FDA reversed course and assigned MRNA an August 5, 2026 PDUFA date to allow for full approval in ages 50-64 and

accelerated approval in age 65+, with full approval contingent on a post-marketing requirement study.

The advisory committee unanimously voted YES—mFlusiva's benefits outweigh its risks for full approval in ages

50-64 and accelerated approval in 65+. For the first vote, the AdCom voted 9-0-0 (Yes-No-Abstain) to the vaccine's

benefit-risk ratio in ages 50-64. For the second vote, the AdCom again voted 9-0-0 to mFlusiva's benefits outweighing

its risks in ages 65+.