SAN DIEGO — The Centers for Disease Control and Prevention bumped San Diego County back up to the agency’s medium-risk level for COVID-19 this week.

That follows a month of rising cases, including a jump by about 26% this week over last.

The CDC bases its risk levels on hospital bed capacity, hospital admissions and the total number of new cases in a given area, according to county health officials, who highlighted the CDC’s update in a statement Thursday.

“The medium-risk level means that San Diegans who are immunocompromised should consider resuming higher levels of protective measures to prevent illness,” officials wrote, in part. “Everyone, regardless of individual risk level, should stay up to date with their vaccines and booster doses and get tested if they develop symptoms of COVID-19.”

While masks are no longer required in most public places, the county “strongly recommends” masking around people who may be particularly vulnerable to the virus, especially indoors, added Dr. Cameron Kaiser, the county’s deputy public health officer.

The county first moved to the CDC’s lowest COVID risk level in early March.

The drop to “low-risk” was a key part of San Diego Unified School District’s reasoning for dropping its mask mandates on campus. Noting the recent rise in cases, the district has already laid out guidelines for a potential return of the requirements.

The region’s Health and Human Services Agency reported 1,897 new coronavirus cases and four deaths Thursday. Only one day in the past week, Tuesday, had fewer than 1,000 new infections. As of Thursday’s update, 169 people were hospitalized with the virus locally.

As the San Diego Union-Tribune’s Paul Sisson notes, current case rates are significantly higher than they were entering the Memorial Day holiday weekend last year.

San Diego’s move back to the higher risk level follows Los Angeles County’s bump back up to medium-risk last week.

Follow these links for a COVID-19 vaccine location in San Diego County and information about coronavirus treatment options, especially for the vulnerable.