The abrupt resignation announcement that came late on Friday, March 28, from Peter Marks, who heads the U.S. FDA's Center for Biologics Evaluation and Research, has sent reverberations throughout the pharma and biotech industries.

Marks, a well-respected hematologist oncologist who has been at the agency since 2012, said in his resignation letter his decision was based on "misinformation and lies" against immunization efforts made by his boss, HHS Secretary Robert F. Kennedy, Jr.

His last day on the job is April 4.

Marks' departure has many companies on edge because of the growing perception that RFK Jr.'s prior statements on vaccine skepticism and potential adverse events will have a chilling effect on the approval of future vaccines. As director of CBER, Marks is also the FDA's top vaccine regulator.

Biopharmas whose pipeline and/or products are heavily vaccine-oriented are under major pressure Monday. Moderna (NASDAQ:MRNA), which turned from a small biotech to a major vaccine player thanks to the development of its mRNA COVID-19 vaccine, is down 9%. BioNTech (NASDAQ:BNTX), which developed a rival mRNA COVID shot with Pfizer (NYSE:PFE), is off ~6%.

Novavax (NASDAQ:NVAX), which markets a traditional COVID shot, is down 7%, while Germany's CureVac (NASDAQ:CVAC), which is focused on mRNA treatments, including vaccines, is off ~8%.

Even Vaxcyte (NASDAQ:PCVX), which earlier Monday released promising mid-stage on data on a pneumococcal vaccine candidate, has plunged 51%.

Wall Street has already taken note of potential impacts. Truist's Asthika Goonewardene said that Marks' statement in his letter that RFK Jr. essentially wants a yes-man suggests the secretary "may have plans for an anti-vax propaganda campaign." 

"Even if COVID vaccines are not specifically targeted, this would not help consumer perception, in our view," Goonewardene wrote.

Marks was also known as a huge supporter of cell and gene therapies. With him gone from the agency, companies in that space could also feel the heat, according to BMO Capital Markets Evan David Seigerman. He added that because Marks' office also oversees biologic drugs, such as monoclonal antibodies, large-cap pharmas and biotechs could also be impacted by his departure.

Gene therapy companies Seigerman sees as under pressure from the forthcoming loss of Marks: CRISPR Therapeutics (NASDAQ:CRSP), Beam Therapeutics (NASDAQ:BEAM), Vertex Pharmaceuticals (NASDAQ:VRTX), 4D Molecular Therapeutics (NASDAQ:FDMT), Neurogene (NASDAQ:NGNE), Intellia Therapeutics (NASDAQ:NTLA), Prime Medicine (NASDAQ:PRME), Rocket Pharmaceuticals (NASDAQ:RCKT), Taysha Gene Therapies (NASDAQ:TSHA), and Verve Therapeutics (NASDAQ:VERV).