This story was updated with more details from county health officials Monday evening.
Health officials in seven Bay Area counties and the city of Berkeley issued a new indoor mask mandate Monday as the region faces a wave of new COVID-19 cases due to the more infectious delta variant and the region’s remaining swath of unvaccinated residents.
The mandate will take effect Tuesday at 12:01 a.m. in Alameda, Contra Costa, Marin, San Francisco, San Mateo, Santa Clara and Sonoma counties as well as Berkeley and require residents to wear a mask indoors in public settings like retail stores and gyms, regardless of whether they’re vaccinated.
“We know that indoor spaces are where most transmission occurs and that’s why we’re basing a masking requirement on an indoor space,” San Francisco Deputy Health Director Dr. Naveena Bobba said during a briefing on the mandate. “Face coverings protect you and those around you, providing an additional layer of protection for vaccinated people too.”
Health officials in the seven counties also urged residents to get vaccinated as soon as possible if they have yet to do so as the prevalence of the delta variant puts unvaccinated people at even higher risk of infection, serious illness and death.
While so-called breakthrough cases in fully vaccinated people are possible, the health officials noted they remain exceedingly rare and the three available vaccines also nearly eliminate the chance of developing serious illness or dying from COVID-19.
Officials in all seven counties said that cases among the unvaccinated continue to far outpace those among vaccinated residents, but vaccinated people’s ability to transmit the delta variant even without developing symptoms made the mandate necessary.
“In many cases, our hospitals are not even admitting vaccinated individuals (who test positive), especially if they’re asymptomatic or show mild symptoms,” Sonoma County Health Officer Dr. Sundari Mase said. “Nonetheless, there is evidence that vaccinated people can spread the virus to others.”
The health officials downplayed the potential of a full vaccination mandate, but they did reiterate their support for businesses that require their employees to get vaccinated.
Contra Costa County Health Officer Dr. Chris Farnitano said officials in the seven counties do not have a planned end date for the mask mandate for now but argued that coronavirus-related hospitalizations will be a better indication of transmission than just local case rates.
“It’s the hospitalizations that we’re really worried about,” he said. “People who are in the hospital with COVID, they’re really sick, they’re gasping for air, they’re struggling to breathe.”
The officials also said they hope requiring masks once again will prevent the need to return to the capacity restrictions and businesses closures of the last 18 months.
“This is a short-term, evidence-based strategy to respond to the delta variant, while keeping our businesses open and supporting the safe reopening of schools,” Marin County Deputy Health Officer Dr. Lisa Santora said.