Shares of major vaccine manufacturers experienced significant declines following the nomination of Robert F. Kennedy Jr. to lead the Department of Health and Human Services.

In the final hour of trading, Moderna's stock fell over 5%, Novavax dropped more than 7%, and Pfizer's shares decreased by over 2%. BioNTech, which partnered with Pfizer on a Covid vaccine, saw its stock close down more than 6%, while British drugmaker GSK ended roughly 2% lower.

Health policy experts warn that Kennedy's anti-vaccine stance could undermine public confidence in Covid vaccinations and routine immunizations, potentially reversing decades of progress in public health. Pfizer, Moderna, and Novavax are still grappling with the impact of declining Covid vaccination rates in the U.S., which have adversely affected their profits over the past two years. Kennedy, founder of the nonprofit Children’s Health Defense, has a history of promoting misleading claims about vaccine safety, including unfounded links to autism.