Moderna Inc.'s stock surged 5.08% during intraday trading on Tuesday, following the release of favorable briefing documents from U.S. Food and Drug Administration staff regarding the company's experimental flu vaccine.

The FDA staff indicated that data from Moderna's flu shot, mFlusiva, may support its effectiveness in adults 65 years and older. The documents noted that the vaccine showed superior relative efficacy compared to a standard-dose flu vaccine in adults aged 50 to 64. This positive regulatory assessment comes ahead of an FDA advisory committee meeting scheduled to review the vaccine.

Analysts viewed the FDA's preliminary assessment favorably, with Jefferies stating that the briefing documents "read favorably." The potential approval of mFlusiva would mark the first mRNA-based seasonal flu vaccine in the U.S., with a regulatory decision expected by early August. The stock movement also coincides with Moderna's announcement of organizational changes, including the appointment of a new chief commercial officer and an expanded role for its president, as the company prepares for multiple potential product launches in 2027 and 2028.