A masked and gloved customer purchases flour at the Berkeley Organic Market and Deli. Credit: Pete Rosos

Six weeks after California dropped a mandate requiring indoor facial coverings as an effort to slow the spread of the novel coronavirus, a coalition of Bay Area health officers has announced that the region must mask up once again as of 12:01 a.m. Tuesday.

According to the new health orders, people in Alameda, Contra Costa, Marin, San Francisco, San Mateo, Santa Clara, San Francisco, and Sonoma counties must wear “well-fitting masks” in any indoor public settings. Businesses are also required to implement the indoor face covering order for all employees. The order also recommends businesses make face coverings available to people who might enter their premises. The mandate applies to everyone over the age of 2, regardless of vaccination status.

“We are deeply fortunate to have vaccines that so profoundly reduce the risk of severe illness and death from the newest, more dangerous variant,” Berkeley Health Officer Dr. Lisa B. Hernandez said in a statement. “Adding a face covering when indoors with others, gives us all an easy, familiar and powerful tool.”

The mandate follows a July 16 masking “recommendation” from that same group of leaders. That recommendation was intended to fight the rapid spike of COVID-19 cases across the region, an uptick that began when California fully reopened on June 15, dropping masking and social distancing rules for all vaccinated people in the process. 

Those relaxed restrictions, along with plateauing vaccination rates nationwide and the highly infectious delta variant of the virus, made Alameda County one of the highest-risk regions in the country, according to information released by the U.S. Centers for Disease Control (CDC) last week. It’s an infection rate that, according to data assembled by the Bay Area News Group, is the highest since March 2021, when Alameda County progressed from the most restrictive “purple” (“widespread risk”) tier to the red (“substantial risk”) tier. If that tier system were still in operation (it, too, was retired on June 15), most of the Bay Area would be back in the purple zone.

According to the Alameda County health department, 77% of residents over the age of 16 have received both doses of the COVID-19 vaccine as of July 29, and 89.5% have received at least one. That the region is so well-vaccinated but COVID-19 continues to spread doesn’t mean that vaccines don’t work, a statement from the coalition of health officers reads. “The Delta variant is infecting a small percentage of the vaccinated in the Bay Area — who still remain strongly protected against severe illness, hospitalization, and death,” the statement reads. “In those instances of infection in a vaccinated person, a face covering prevents further spread.”

These remarks are an echo of internal CDC documents first reported on by the Washington Post, which said that internal and external studies reveal that vaccinated people who suffer from “breakthrough infections” of the delta variant have viral loads equal to people who were never vaccinated at all. According to the CDC, vaccinations are still vital, as they will cut down on the infection rate and will decrease the severity of infection — but the viral load data suggest that those who are infected can easily pass the virus on. That’s why the CDC announced Tuesday that “given higher transmissibility and current vaccine coverage, universal masking is essential to reduce transmission of the Delta variant,” but the agency fell short of issuing an actual mandate.

The state of California issued a similar recommendation on Wednesday, but it left the business of mandates up to individual counties. Since July 17, masks have again been mandatory indoors in LA County. As of July 30 they have been required in Yolo and Sacramento counties. And now, seven Bay Area counties and Berkeley will join the mask mandate movement for all public spaces, with an end date that has yet to be determined.

"*" indicates required fields

See an error that needs correcting? Have a tip, question or suggestion? Drop us a line.

Eve Batey has worked as a reporter and editor since 2004, including as the co-founder of SFist, as a deputy managing editor of the SF Chronicle and as the editor of Eater San Francisco.