An unhealthy combination of factors resulted in an unhealthy day on the stock market for next-generation healthcare company BioNTech (BNTX -6.58%). Investors were concerned about the latest top-level appointment in public health, plus an analyst became a bit more bearish about the company's future.

When the smoke cleared, BioNTech's shares closed the day more than 6% lower. That was a more dramatic slide than the 0.8% drop of the S&P 500 index.

A controversial pick

The Food and Drug Administration (FDA), a division of the government's Department of Health and Human Sciences (HHS) headed by Robert Kennedy Jr., announced that appointment Tuesday morning. It has selected Dr. Vinay Prasad to head its Center for Biologics Evaluation and Research, the division responsible for approving vaccines.

Image source: Getty Images.

This is a controversial move, as Prasad came to prominence during the COVID-19 pandemic as an often sharp critic of policies enacted to fight the disease.

Following the announcement, prices dropped for numerous publicly traded companies that are either developing or have marketed vaccines -- BioNTech among them.

Price target shaved

In what's a case of bad timing, after market hours on Monday Citigroup's Geoff Meacham cut his price target on the company's stock. Following its first-quarter earnings report (published Monday morning), Meacham changed his fair value assessment to $140 per share from his preceding $145.

According to reports, Meacham wrote that current U.S. policy on respiratory vaccines is shaky. However he was impressed with the company's first-quarter performance, and feels it has a good cash runway and promising treatments in development.

While BioNTech does have an impressive recent past, notably with the Comirnaty COVID-19 vaccine it developed with Pfizer, it's still a young company that needs to bring more products to market to be a compelling investment. That said, it's a stock well worth keeping an eye on.