As CBS News' Lilia Luciano reports, the Centers for Disease Control has updated its mask guidance as the Delta variant sends new COVID infections skyrocketing. Some vaccinated Americans are now being advised to mask up. Dr. Ebony Jade Hilton, co-founder and medical director of Goodstock Consulting and an associate professor of anesthesiology and critical care medicine at the University of Virginia, joins CBSN's Elaine Quijano with more on the pandemic's fourth wave.
