Alameda County was among the three latest counties in the greater Bay Area to fall 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 effective Wednesday 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.

The move also keeps the Pleasanton Unified School District on track to reopen middle and high schools effective this Thursday (March 11), district officials confirmed to the Weekly.

"I want to express my gratitude for the PUSD elementary team members who worked diligently to get schools ready for the return of students and staff beginning last week, as well as to our secondary school teams who are working to be ready for our middle and high school students on Thursday," PUSD Superintendent David Haglund said in a statement.

"I am grateful for each of you, as we all have important roles to play in the days and weeks ahead. Let’s continue to collaborate and do what we need to do to keep our community safe -- and our schools open," he added. "I am incredibly proud of us. Specifically, how we all have come together -- to show up and to be there for our students in a time of great need. It’s the US in PUSD that makes Pleasanton a place that inspires students to make a better world."

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."

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."

Key restrictions lifted in Pleasanton and the rest of Alameda County due to the red tier status include:

* Restaurants can offer indoor dining at 25% maximum capacity or 100 people, whichever is fewer.

* Retail stores expand to 50% maximum capacity and food courts permitted with indoor dining restrictions.

* Grocery stores can expand to full capacity while following retail industry guidance.

* Movie theaters can reopen at 25% maximum capacity or 100 people, whichever is fewer.

* Museums, zoos and aquariums can reopen at 25% maximum capacity.

* Gyms, fitness centers and studios (including at hotels) can open indoors at 10% maximum capacity. Climbing walls are permitted.

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.

-- Story by Bay City News Service, with Pleasanton Weekly editor Jeremy Walsh contributing localized information.