Though most Bay Area counties remain far from reaching their own criteria for lifting mask requirements, starting Friday vaccinated people won’t need face coverings in some indoor settings in San Francisco and Marin County.

And Contra Costa County plans to join them Nov. 1. The partial lifting in those places applies to gyms, fitness centers, office settings, employee commuter vehicles, religious gatherings and college classes with no more than 100 people where all are proven vaccinated. That means no kids under 12, who can’t get the shots yet — for indoor places with young kids, everyone must still wear the masks.

“This will allow vaccinated people to feel safe removing their masks at the office and when they’re working out at the gym,” Contra Costa County Health Officer Dr. Chris Farnitano said Thursday. “Of course, people in these places can keep wearing masks if that makes them feel more comfortable.”

The limited loosening of the mask rule was a welcome change to San Francisco’s MX3 Fitness owner Glenn Shope.

“It is definitely beneficial because it’s a lot easier to work out doing high-intensity stuff without a mask on,” Shope said. “It takes the onus off of the gym owners and trainers to constantly be enforcing the mask protocols, reminding people to put the mask on their nose and mouth, put it back on again after they’re done drinking, hydrating. It also signals to our members that it’s safe to be in a gym again.”

The limited mask rule changes come even though most Bay Area counties haven’t hit the thresholds they laid out last week for allowing vaccinated people more broadly to lose the masks in most indoor public settings, including grocery and retail stores and restaurants and bars when they aren’t eating or drinking.

Under those criteria, which eight of the nine county health officers agreed to, the indoor mask requirement for the vaccinated can drop after three weeks of the county’s COVID-19 transmission rate reaching the U.S. Centers for Disease Control and Prevention‘s yellow “moderate” tier. At least 80% of the county’s entire population also must be fully vaccinated, and hospitalization rates must remain low and stable.

Of the nine Bay Area counties, only Marin appears close to reaching those criteria. It reached the CDC’s moderate transmission rate Wednesday, putting it on a path to dropping the full indoor mask rule next month if it stays there. Hospitalizations are low, and 77.4% of the county population is fully vaccinated, the CDC said, the highest Bay Area rate.

Most other Bay Area counties are in the CDC’s orange “substantial” transmission tier, while Napa’s rate remains in the red “high” level. Solano County had not joined the others in imposing their own indoor mask requirements back in August.

San Francisco was first to announce Friday’s partial lifting of the mask requirement. Asked why Santa Clara County wasn’t planning similar exceptions, Health Officer Dr. Sara Cody noted that San Francisco has a vaccine passport requirement to enter restaurants, bars, gyms, clubs, large indoor events or other indoor places serving food and drinks, and Santa Clara County does not.

“We’ve always sought to have rules as simple as possible, as easy as possible for the public to understand, here in Santa Clara County,” Cody said last week.

Marin and Contra Costa counties, however, don’t have a vaccine passport rule like San Francisco, either. But Santa Clara, Alameda, San Mateo and Sonoma county officials said Thursday they have no plans to allow mask rule exceptions like San Francisco, Marin and Contra Costa. Napa County officials did not respond.

“Our case rate and hospitalizations are too high, and our vaccination rate is too low right now to lift the mask mandate, and we are heading into a potentially bad winter season,” said Sonoma County spokesman Matt Brown.

The indoor mask exceptions allowed Friday won’t apply to places like restaurants and bars, except while patrons are eating and drinking, even in San Francisco where vaccination is required to enter them. After she was criticized last month dancing without a mask in a city bar, San Francisco Mayor London Breed shot back that she wasn’t going to put her mask back immediately after taking a sip to satisfy the “fun police.”

Transmission rates have been falling since August when the summer wave of infections driven by the highly contagious delta variant of the virus crested, thanks to a combination of rising immunity from vaccination or recovery from COVID-19 and stepped up measures to control spread such as the mask rules.

Even so, the virus remains active. Most U.S. states remain in the CDC’s high transmission level, with only California, Florida, Alabama, Hawaii and Connecticut reaching the moderate rate.

Federal and state health officials in May and June said the vaccinated no longer needed to wear masks indoors in what proved to be premature reopening guidance that failed to factor the growing delta threat. While the vaccinated are less likely to be infected, hospitalized or killed by the virus, the CDC acknowledged over the summer they still can catch and spread it and advised even those who had the shots to wear masks where transmission rates are substantial or high.

California recommended masks indoors for everyone, and the eight Bay Area counties made that an order in early August.

Even when the local orders drop, federal and state rules still will require people to wear masks regardless of vaccination in public transportation, K-12 school buildings, homeless shelters, and health care, elder care and correctional facilities. State orders require the unvaccinated to wear masks in indoor places including retail stores, theaters, family entertainment centers and government buildings.