A wave of COVID is sweeping California, with the state seeing a continued rise in new confirmed cases and hospitalizations as some officials urge the public to take stricter precautions.
The extent of the recent increase has prompted some county-level health officials to recommend that residents reconsider wearing masks in indoor public spaces, at least until transmission declines.
California is currently experiencing “high” levels of coronavirus in wastewater. according to to the US Centers for Disease Control and Prevention. The increase is being seen throughout the Golden State, from Los Angeles County to the San Francisco Bay Area and areas around the state capital.
Center for Disease Control and Prevention (CDC) assessments that coronavirus infections are either “increasing” or “likely increasing” in 30 states, including California. Twenty-one states have either “very high” or “high” levels of the virus in their wastewater. Of all U.S. regions, the West has the highest rate of coronavirus contamination in wastewater, followed by the South.
“California is experiencing a summer wave of COVID,” said Dr. Aimee Sisson, health officer for Yolo County, west of Sacramento.
The rate at which laboratory tests come back positive for coronavirus also continues to increase. For the week ending Aug. 23, 12.07% of tests statewide were positive, compared to 6.03% for the week ending July 26.
A similar jump in rates was seen in Los Angeles County, where the test positivity rate was 13.44%, up from 8.11% four weeks earlier; in Orange County, 18.1%, down from 9.4%; and in San Francisco the rate was 8.7%, down from 7.1%.
Dr. Elizabeth Hudson, regional director of infectious diseases at Kaiser Permanente in Southern California, said she received a lot of calls about outpatient COVID-19 cases while she was on call over Labor Day weekend.
“We're definitely seeing an increase in COVID patients,” Hudson said. “Fortunately, hospital-based cases are few and far between. However, wastewater levels in Los Angeles are still rising, so we have not yet reached the top of this current wave.”
Overall, this summer hasn't seen as much COVID activity as a year ago, when the state experienced its worst summer surge since 2022.
“We'll have to see where things go in the next one to two weeks to have a better idea” of where we end up, Hudson said. She said students returning to school and after traveling and socializing over the holiday weekend could contribute to further spread of the virus.
Across California, the overall rate of COVID-19 hospitalizations remains “low” but increasing.
For the week ending Aug. 23, there were 3.62 COVID-related hospitalizations per 100,000 residents; compared with a comparable reading of 1.9 four weeks earlier. The most recent rate is also higher than during the winter peak, when the rate peaked at 2.61 hospitalizations for every 100,000 residents.
Emergency department visits for COVID-like illnesses also increased in Los Angeles, Orange and Santa Clara counties. In Los Angeles County, 2.8% of emergency room visits were for illnesses such as fever, cough or sore throat, up from 2.2% four weeks earlier. In Orange County, 2.6% of ER visits were for COVID-like illnesses, down from 1.5%.
“The current positivity rate for COVID-19 is higher than at any time last winter,” according to Dr. Christopher Zimmerman of the Orange County Public Health Agency's Division of Infectious Disease Control and Dr. Regina Chinsio-Kwong, the county's public health officer.
As of Aug. 23, 1.9% of total hospitalizations in Orange County were due to COVID — more than at any time during the winter but less than half of last summer's peak of 4%.
However, it is unclear “how high and severe the COVID wave might be this summer,” Zimmerman and Chinsio-Kwong said, noting that the rise started later this year than in 2024.
In Los Angeles County, hospitalizations for COVID-19 are now roughly in line with last winter's peak but remain below the peaks of the last two years, according to the Los Angeles County Department of Public Health.
Sisson said coronavirus levels are high in wastewater from both Sacramento and West Sacramento, one of Yolo County's most populous cities. Sisson recommended that everyone ages 2 and older in West Sacramento “wear a mask when around other people in indoor public spaces” because coronavirus levels in wastewater there are high.
As for other areas of Yolo County, including UC Davis and Woodland, where virus levels in wastewater are considered “moderate,” Sisson said she recommends people wear masks around other people indoors “if they are over 65, have a weakened immune system, have an underlying medical condition that puts them at greater risk of severe illness COVID-19, or spending time among people who fall into these categories.”
“Wearing a high-quality mask, such as an N95, KN95 or KF94, that fits well will still provide good protection,” Sisson said.
Coronavirus cases are rising in Sacramento County and coronavirus wastewater levels are considered high, according to Casey Camacho, a spokesperson for the Sacramento County Department of Health.
The San Francisco Department of Public Health is also urging people to “consider wearing a well-fitting mask in crowded indoor spaces, including when traveling, and staying home if they feel sick.” Coronavirus levels in San Francisco's wastewater and COVID hospitalizations have risen this summer “but remain below last summer's peaks.”
In Santa Clara County, Northern California's most populous county, COVID-related hospitalizations have increased and coronavirus levels are “high” in San Jose and Palo Alto sewer sheds. Current levels of the virus in wastewater are now similar to levels seen in the summer of 2023, but have not reached the peak of last summer. Hospitalization rates due to COVID also remain lower than in recent summers, public health officials said.
An updated version of the 2025-2026 COVID-19 vaccine is expected. will be available for a few days at select pharmacies nationwide, such as Walgreens and CVS. But some people are expressing frustration with new rules issued by the Trump administration that effectively require young, healthy people under age 65 who do not claim to have an underlying medical condition to consult with a health care provider to get a COVID vaccine in the fall.
“Vaccination remains one of the most effective ways to prevent severe illness and death from COVID-19,” Sisson said.
That requirement was criticized by Dr. Jerome Adams, a former surgeon general who served during the first Trump administration. IN posts On social media, Adams said requiring people to consult with a health care provider before getting a COVID vaccine creates “real barriers to access.”
“Even if you have insurance and can go to see a doctor (which is important in the US), many doctors will be reticent to prescribe drugs 'off-label' given the (in many cases unfounded) recent rhetoric from HHS leaders,” Adams wrote, referring to the US Department of Health and Human Services, which is run by vaccine skeptic Robert F. Kennedy Jr.
Kennedy, who has previously been dismissive of vaccines, said he wants more research into COVID-19 shots. Other health experts said more testing of COVID vaccines is not necessary given the extensive testing conducted before they were first distributed and their track record since then.
“The point? That “100% of those who choose the Covid vaccine can get it” is both statistically (according to HHS’s own data) and pragmatically untrue. The continued repetition of this reflects a lack of knowledge, empathy or integrity,” Adams wrote.
