You are using an older browser version. Please use a supported version for the best MSN experience.

U.S. in vaccination race against rapidly mutating Covid virus

CDC Director Dr. Rochelle Walensky talks with Rachel Maddow about concerns that mutations of the coronavirus will undermine the effectiveness of the current vaccines, making it imperative that vaccinations stop the spread of the virus before that can happen.

UP NEXT

UP NEXT

More From MSNBC

More From MSNBC

image beaconimage beaconimage beacon