Alarm: Dr. Fauci on new 2021 Covid-19 strains that could be worse than 2020

As U.S. Covid-19 cases drop and the vaccine rollout continues, Dr. Fauci shares reasons for both optimism and concern, emphasizing that vaccines and CDC protocols work to curb the spread, while reacting to warnings from some experts that new strains of Covid could be literally worse than the coronavirus that ravaged the world in 2020. This is an excerpt from an interview with MSNBC’s Ari Melber.