Even though the FDA granted emergency use authorizations for the Pfizer/BioNTech and Moderna vaccines in December 2020, the clinical trials the FDA will rely upon to ultimately decide whether to license these vaccines are still underway and are designed to last for approximately two years to collect adequate data to establish if these vaccines are safe and effective enough for the FDA to license. The abbreviated timelines for the emergency use applications and authorizations means there is much the FDA does not know about these products even as it authorizes them for emergency use, including their effectiveness against asymptomatic infection, death, and transmission of SARS-CoV-2, the virus that causes the disease. https://www.statnews.com/2021/02/23/federal-law-prohibits-employers-and-others-from-requiring-vaccination-with-a-covid-19-vaccine-distributed-under-an-eua
