Drivers wait for their coronavirus vaccines at the Oakland Coliseum vaccination site. Alameda County, which includes the Coliseum, is one of three Bay Area counties to move out of the purple tier Tuesday. (Photo courtesy Paul Wade/U.S. Forest Service/Flickr)

Three more counties in the greater Bay Area fell out of the state’s most-restrictive coronavirus reopening tier Tuesday, bringing the number of the region’s counties in the red tier to eight.

Alameda, Santa Cruz and Solano counties all moved out of the purple tier of the state’s Blueprint for a Safer Economy following declines in their case and test positivity rates.

Whereas most business sectors were required to operate outdoors or remain closed under purple tier restrictions, the tier changes will allow the three counties to resume indoor operations at 10-25 percent capacities for businesses like gyms, restaurants, movie theaters, museums, zoos and aquariums.

Santa Cruz County Health Officer Dr. Gail Newel said that while the pandemic has not completely abated, the tier change and the county’s vaccination progress offer a clear path to recovery.

“This change is a sign of our community’s commitment to health and to each other,” Newel said. “The light at the end of the tunnel is getting brighter.”

In addition to the tier change, Newel lifted the county’s restrictions on visitors at nursing homes, long-term care facilities and other congregate living facilities.

Alameda County Health Officer Dr. Nicholas Moss also warned that the risk of contracting the coronavirus still requires residents to take caution, especially with the majority of county residents not yet receiving a vaccine.

“Alameda County’s case rate is on the decline and vaccinations of vulnerable residents and our frontline workers are progressing but the COVID-19 pandemic is not over,” Moss said in a statement. “As more activities and businesses open indoors and more people from different households mix, the risk of becoming infected increases.”

Recent changes to the state’s guidance on crowds at large outdoor venues will allow the Santa Cruz Beach Boardwalk and the Oakland Coliseum in Alameda County to reopen after April 1.

The state also plans to modify the thresholds for assignment to each tier of the Blueprint in the coming days, based on the number of vaccines administered in the state’s hardest-hit communities.

The threshold changes — which would include pushing the number of cases per day per 100,000 residents required for purple tier assignment from seven to 10 — could potentially keep the Bay Area’s red tier counties out of the purple tier for much longer.

As of Tuesday, only Contra Costa, Monterey and Sonoma counties remain under purple tier restrictions in the 11-county greater Bay Area.