New viral strains continue to spread across the country, which has added to the urgency of getting as many people vaccinated as possible. With supplies of the two vaccines currently available in the U.S. falling well short of demand, mandating vaccination is likely not a realistic scenario now. But it could be in the coming months. Is it legal for states, private employers, and even airlines, to mandate a vaccine that has only been approved for emergency use? Who could be held responsible if something goes wrong after getting the shot? Carmel Shachar, MD, executive director of The Petrie-Flom Center for Health Law Policy at Harvard Law School, joins us to explore those legal questions, and more.