https://www.siliconvalley.com/2020/12/22/can-employers-make-covid-19-vaccination-mandatory/

U.S. employers can make COVID-19 vaccination mandatory, with some exceptions.

Experts say employers can require employees to take safety measures, including vaccination. That doesn’t necessarily mean you would get fired if you refuse, but you might need to sign a waiver or agree to work under specific conditions to limit any risk you might pose to yourself or others.