Shares of Moderna and Novavax dropped more than 11% and 6%, respectively, in early trading. Meanwhile, the SPDR S&P Biotech ETF slid nearly 5%. Shares of Pfizer , which has broader businesses to insulate it from damage to its vaccine portfolio, lost about 2%. The departure of Peter Marks, the Food and Drug Administration's top vaccine regulator, has raised fresh fears about whether the Trump administration will quickly approve and promote critical shots. In his position, Marks oversaw the introduction of Co ...