U.S. coronavirus death toll surpasses 400,000 as virus mutations spread

The U.S. coronavirus death toll has surpassed 400,000, just one day before President-elect Joe Biden's inauguration. New variants are emerging across the country, adding new urgency to vaccination efforts. CBS News correspondent David Begnaud has the latest, then Dr. Uzma Syed joins CBSN's Elaine Quijano to discuss what to expect in the coming weeks.