Novavax (NVAX) shares plummeted 5.15% in Tuesday's trading session, continuing the downward trend seen in vaccine-related stocks following the resignation of a key FDA vaccine regulator. The ongoing volatility in the sector reflects investor concerns about the future of vaccine regulation and development in the United States.

The sharp decline comes in the wake of Peter Marks' announcement last Friday that he would be stepping down as the Food and Drug Administration's main vaccine regulator. Marks cited friction with Robert F. Kennedy Jr., the current secretary of the Department of Health and Human Services, as the reason for his departure. This leadership shake-up has sent shockwaves through the biotech and pharmaceutical industries, particularly affecting companies with significant vaccine businesses.

Wall Street analysts have expressed serious concerns about the situation, with some calling for a re-evaluation of Kennedy's role at HHS. The uncertainty surrounding future vaccine policies and potential changes in FDA leadership has led to increased market volatility for vaccine manufacturers like Novavax. Investors are closely monitoring the situation, as any shifts in vaccine regulation or approval processes could have significant implications for companies in this space.