Delta variant fuels concerns of fourth coronavirus wave as cases rise across the U.S.
The Delta variant is exploding across the U.S., with the CDC warning it now makes up 83% of COVID-19 cases nationwide. As CBS News' Manuel Bojorquez reports, its quick spread follows a decline in vaccinations. Then, Dr. Jessica Shepherd, chief medical officer at Verywell Health, joins CBSN's Elaine Quijano to discuss the latest on fighting the pandemic.