Novavax (NVAX) shares plunged 5.15% in intraday trading on Tuesday, as investors reacted to the resignation of a key FDA vaccine regulator and growing concerns over the influence of vaccine skeptic Robert F. Kennedy Jr. as head of the Department of Health and Human Services (HHS). The stock's decline reflects broader market jitters in the vaccine and biotech sectors following these developments.

The sell-off was triggered by the announcement that Peter Marks, the Food and Drug Administration's main vaccine regulator, would be resigning effective April 5. Marks cited friction with HHS Secretary Robert F. Kennedy Jr., stating that Kennedy wanted "subservient confirmation of his misinformation and lies." This high-profile departure has raised alarms among investors about the future direction of vaccine policy and regulation in the United States.

Analysts from Cantor Fitzgerald have called on the Trump administration to "re-evaluate" Kennedy's role at HHS, warning that his "apparent anti-science and libertarian agenda is putting people's lives in jeopardy." The uncertainty surrounding vaccine policy and potential changes in FDA leadership have led to increased volatility in vaccine-related stocks. Truist analysts expect companies with vaccine businesses, like Novavax, to remain volatile as the market processes these developments and assesses their potential impact on the future of COVID-19 vaccines and the broader biotech industry.