What you need to know about mix-and-match COVID-19 boosters

A sign displays the types of COVID-19 vaccination doses available at a Walgreens mobile bus clinic on June 25, 2021 in Los Angeles, California.
A sign displays the types of COVID-19 vaccination doses available at a Walgreens mobile bus clinic on June 25, 2021 in Los Angeles, California. Photo credit Mario Tama/Getty Images
By , KCBS Radio