Millions of Michiganders live in counties where COVID transmission rates have risen to "substantial" or "high" levels. That's the threshold where the CDC is recommending that even fully-vaccinated people wear masks indoors.
33 counties are now in those higher-risk categories, including Oakland and Macomb. That's up from just six counties last week, a sign of how quickly the delta variant may be spreading in the state.
Dr. Joel Fishbain is the Medical Director for Infection Prevention at Beaumont Hospital.
He says with new evidence that vaccinated people may be able to transmit the delta variant, the greater the risk is of the virus continuing to spread and evolve.
"I'm concerned that the next variant might escape previous immunity and might escape vaccination," Fishbain said. "That's why we have to vaccinate everybody as quickly as we can try to prevent any transmission."
Fishbain says he's personally encouraging everyone, regardless of where they live, to return to universal masking indoors.
The vaccines are still highly effective at preventing severe illness or death.
