A sharp decline in COVID-19 cases has led Santa Clara and San Mateo counties to adjust how they are handling the pandemic, such as reducing testing sites and closing some isolation shelters for homeless residents during previous outbreaks.

Santa Clara County plans to maintain its mass testing and vaccination infrastructure while developing a nimble model that will allow it to scale up or down as demand changes, Health Officer Dr. Sara Cody told the Board of Supervisors on Tuesday. The county will continue to maintain overall preparedness and outbreak-response programs.

"While our cases are still declining the rate of decline does appear to be slowing just a little bit," she said.

The county has achieved an 84.9% vaccination rate for all residents, and 68.8% of eligible residents have received boosters, according to the county's COVID-19 online dashboard.

"We saw more cases — many more cases — during the omicron surge than at any previous surge, and this was the case even in our very highly vaccinated population. This was in large part due to the incredible transmissibility of omicron," she said.

She noted that the county saw a rise in the number of deaths from the omicron variant outbreak. At the peak in late January, 46 residents died in a week compared to 26 during the delta surge, according to county dashboard data. Although on an individual basis the cases were milder, the sheer numbers of cases on a community level caused by omicron were such that even a small proportion of serious illnesses resulted in a higher number of deaths, she said.

"We must continue to think about our community and not just individuals. On a community level, omicron was much, much worse than delta," she said.

Cody said the county is preparing for future surges. Officials are strengthening the public health system through continuing disease surveillance, engaging with the community and working with health care providers and the public to prepare for other emerging variants. The county is also focusing on health equity and outreach to underserved communities, which have been hit hardest by the virus.

How the county will track the virus and understand new surges and variants also is changing. The Centers for Disease Control and Prevention has shifted its focus on the outcome of the virus, such as hospitalization rates — a "community level" model — rather than the amount of transmission, she said. The data from this model lags, however, and makes identifying warning signs of surges slower, she said.

As more people have shifted to home testing, the county needs to rely on other systems to understand transmissibility, she said. County health officials continue to surveille DNA from the virus and its variants found in wastewater. The wastewater surveillance program, which began in fall 2020, has been a reliable source of information about where outbreaks are occurring and how the spread is trending, she said.

The county also is ending its at-home and financial assistance program referrals, no longer taking in new clients. It expects to process all pending requests by April 30 and release 80% of staff to their regular jobs by May 1. They'll reduce the current two leased hotels used for isolation cases to one by March 15 and begin to prioritize placements to unhoused people coming from congregate-care settings and hospitalizations. A program will be put in place to transition people to other supportive services.

Supervisor Mike Wasserman asked staff to develop a "playbook" for handling COVID-19 based on lessons learned during the past two years of the pandemic that relate to infrastructure, testing and vaccinations.

"Another virus may come to town and be the next COVID," he said.

County administrators plan to bring a summary before the board at a future date.

San Mateo County mass-testing center to shut down

Health officials in San Mateo County plan to close the COVID-19 testing site at the San Mateo County Event Center early next week, they told the county Board of Supervisors on Tuesday.

The drive-thru center will shut down after March 15, San Mateo County Health Chief Louise Rogers said. The center isn't considered essential at this point, since virus case rates have declined by 96% since the peak of the latest surge on Jan. 8. Of all county residents, 83% are now fully vaccinated.

Rogers thanked the event center's leadership and staff for their cooperation.

"We just could not have mobilized at the level we did without their partnership," she said.

The county will continue to sponsor vaccine clinics in East Palo Alto, Redwood City, San Mateo, Half Moon Bay, Day City and South San Francisco, said Dr. Anand Chabra, San Mateo County Health's COVID-19 mass vaccination section chief.

As of March 6, 89% of all county residents have received at least one dose of the vaccine. The clinics will continue to target communities where vaccinations have been the lowest: 68% of Black residents, 79% of Hispanics, 66% of Pacific Islanders and 66% of children ages 5 to 11 years old have received one shot of the vaccine, he said.

"Our message that it's not too late to be vaccinated and to get a booster remains relevant, as vaccination is the most important action that every eligible resident can take to protect themselves from the risks of severe disease or death," he said.

The county also is pulling back on contact tracing and will focus on high-risk populations such as residents of congregate-care facilities, shelters and jails.

Rogers noted that hospitalizations also continue on a downward trend, and there are only two residents in "safe isolation" in motels or other locations that are sheltering homeless people who test positive for the virus.

But while the county might be winding down its larger-scale response to the pandemic, officials are still keeping a close eye on the situation in the event there is another surge.