Moderna shares fall premarket as FDA declines to review new flu shot vaccine

Shares of Moderna MRNA.O fell 10.3% premarket on Wednesday after the U.S. Food and Drug Administration declined to review the company's application for approval of a new influenza vaccine, underscoring shifts in U.S. vaccine policy.

The move comes just weeks after the U.S. rewrote its longstanding childhood immunization guidance and scaled back routine vaccine recommendations against infectious diseases including influenza, a shift that has concerned public-health officials.

Moderna said its choice to compare the vaccine, mRNA‑1010, with an already licensed standard-dose seasonal influenza vaccine was the sole reason the FDA refused to initiate a review of the application.

This "raises the risk of a more protracted U.S. path for both the standalone flu shot and Moderna's flu/COVID combination vaccine, given the FDA's stance on the comparator," Jefferies analysts said.

The FDA letter contradicts prior written communication from the Center for Biologics Evaluation and Research, Moderna said, adding that it has requested a meeting with the health regulator to understand the path forward.

The vaccine is currently under review in the EU, Canada and Australia, with the company expecting potential approvals to come in late 2026 or early 2027.

"This fits a broader pattern of the FDA 'moving the goalposts', the trial met its primary endpoints in 43,808 participants and filings were accepted in the EU, Canada and Australia, yet we struggle to see current FDA leadership reversing course," RBC Capital Markets analysts said.

The U.S. market is currently served by several FDA‑approved flu vaccines, including those produced by UK's AstraZeneca AZN.L and France's Sanofi SASY.PA.

Moderna's shares have risen about 42% so far this year after falling 29% in 2025.

-Rashika Singh/Reuters