The U.S. Equal Employment Opportunity Commission (EEOC) on May 28, 2021 issued updated guidance on vaccinations. The relevant excerpts are attached and the full EEOC guidance is here https://www.eeoc.gov/wysk/what-you-should-know-about-covid-19-and-ada-rehabilitation-act-and-other-eeo-laws
This is only guidance from the EEOC. It is not law. The guidance also does not preempt state or local law, nor does it address the issue of the FDA regulations requiring notice to individuals that use of a product authorized under an Emergency Use Authorization is voluntary.