What to know about Pfizer and Moderna's COVID-19 vaccine trials

The nation's top infectious disease expert, Dr. Anthony Fauci, says as many as 20 million Americans could get a COVID-19 vaccine by the end of 2020. Dr. Uché Blackstock, an emergency physician and founder of the group Advancing Health Equity, spoke to "Red and Blue" host Elaine Quijano about the encouraging early results from vaccine trials by Moderna and Pfizer.