What happened In what hardly qualifies as a surprising development, shares of both Pfizer (NYSE: PFE) and BioNTech (NASDAQ: BNTX) fell in price on Thursday. This was on the back of a Supreme Court decision that struck down a key government vaccination mandate. The two companies are perhaps best known by the general public these days for the Comirnaty coronavirus vaccine, so they were directly in the line of fire when the decision was handed down. After the smoke cleared, Pfizer's stock price fell by nearly 2%, while the far smaller and less diversified BioNTech suffered an 8% hit. Image source: Getty Images. So what The Supreme Court actually ruled on two aspects of the government's existing corporate vaccination rules. The one that was blocked covered large employers, whose workers were required to get vaccinated against the coronavirus or be masked and subject to regular weekly testing. However, the court upheld the federal mandate on workers at healthcare enterprises that receive public funding for the Medicare and Medicaid programs. During oral arguments on the mandates last Friday, several justices seemed to cast doubt on the federal government's authority to enact such sweeping mandates. However, in previous rulings the Supreme Court had upheld certain vaccine mandates at the state level. Now what While President Biden has pledged to continue pushing unvaccinated Americans to get their jabs, the court's decision to strike down the employer mandate isn't going to do wonders for BioNTech stock. In contrast to Pfizer, which has a bulging portfolio of commercialized medicines and a large pipeline, the Germany-based company's current fortunes are strongly tied to the fate of Comirnaty. 10 stocks we like better than BioNTech SEWhen our award-winning analyst team has a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* They just revealed what they believe are the ten best stocks for investors to buy right now... and BioNTech SE wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of January 10, 2022 Eric Volkman has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.Source