COVID Updates: Omicron variant takes hold in California. Where cases are surging
California has become engulfed in another winter surge of COVID-19, with the state health department’s first post-Christmas update showing test positivity quadrupling in the past two weeks as the highly contagious omicron variant grows dominant.
California Department of Public Health officials reported nearly 87,000 new cases in a Tuesday update that covered the four-day stretch from Christmas Eve through this Monday.
The addition propelled the state past the milestone of 5 million total lab-confirmed coronavirus infections. More than 75,000 Californians have died of the virus during the nearly two-year pandemic.
The statewide daily case rate for COVID-19 has climbed from 14.7 to 25.3 per 100,000 residents since Dec. 13, according to CDPH. The latest rate is likely an underestimate, potentially a severe one, due to testing limitations and data reporting delays related to the recent holiday.
After plateauing between about 2% and 2.5% for most of October and November, California’s test positivity rate is climbing more steeply than in any previous surge: from 2.4% on Dec. 14 to 9.7% by Monday, with the latter marking the state’s highest percentage since January. CDPH had reported positivity at 5.4% last Thursday.
The swift increase is consistent with the exponential growth observed in recent days and weeks across other parts of the U.S. where omicron has taken hold, particularly Northeastern states including New York. The U.S. as a whole is on the brink of reaching its highest seven-day case rate of the entire pandemic, according to Johns Hopkins University.
Health officials have expressed concern for weeks — even before the latest variant of concern was discovered in late November by scientists in South Africa — that travel and indoor gatherings around the winter holidays could spur another sharp surge in virus transmission, and omicron has only heightened that concern.
California’s latest positivity rate already well exceeds the peak from this summer’s delta variant surge, which maxed out around 7.2% in early August. The metric hit 17% last winter.
Where is the surge hitting hardest?
More than a dozen of the state’s 58 counties now have positivity above 10%, including the Southern California counties of Riverside (13.1%), Orange (11.9%), San Bernardino (11.8%), San Diego (11.5%), Ventura (11%), Los Angeles (10.8%) and Santa Barbara (10.2%) along with several rural counties, according to Tuesday’s update from state health officials.
San Francisco is near the ballooning statewide average at 9.5%.
Test positivity across most Sacramento-area counties ranges from 7% to 9%, except Yolo County (2.3%), which has among the state’s most aggressive testing regimens.
San Francisco, which also has rigorous testing relative to other counties, now has the state’s highest per-capita case rate at 39 per 100,000, according to Tuesday’s update from CDPH, which is its highest rate of the entire pandemic.
The city has one of the highest vaccination rates in the nation, with its local health office reporting that 84% of residents ages 5 and older are fully vaccinated. It also was the nation’s first health jurisdiction to detect the omicron variant, announcing that discovery Dec. 1.
Experts say full vaccination appears significantly less effective in preventing COVID-19 infection with omicron than with the previously dominant delta variant, though a booster dose appears to restore some efficacy.
Pfizer and Moderna’s vaccines are also believed to remain effective against omicron in preventing severe illness and death, which is why officials at the state and local level continue to urge fully vaccinated residents to get boosted as soon as they are eligible.
Statewide, about 71% of eligible Californians 5 and older are fully vaccinated with two doses of Pfizer or Moderna or one dose of Johnson & Johnson, according to CDPH data updated Tuesday. About 9.4 million have received a booster dose. That’s about 45% of fully vaccinated residents who are due for a booster and just under one-quarter of California’s overall population.
Emerging studies appear to show that omicron might be less severe than delta, with recent data from the United Kingdom suggesting roughly 50% fewer confirmed cases may end up hospitalized. It will become clearer within the next few weeks whether a similar decline in hospitalization proportion is observed in California.
However, health experts continue to sound the alarm because omicron can still overwhelm health systems if the sheer volume of infections grows so high that it outweighs a drop in severity.
Hospital patient totals growing across California
Hospitalizations with COVID-19 are beginning to climb quickly in California. CDPH on Tuesday reported 4,378 patients with confirmed COVID-19 in hospitals statewide, up 9% in a single day and about 40% higher than in late November.
The latest patient total is roughly half the peak of the delta surge and about one-fifth the high point from last winter’s surge, which saw close to 22,000 hospitalized in early January and nearly 5,000 in intensive care units.
The steepest recent hospitalization increases have come in Southern California and in parts of the Bay Area.
Los Angeles County’s patient total has nearly doubled, from 569 to 1,069, since the start of December, with most of that increase coming in just the past week.
In the Bay Area, Alameda County has risen from 61 to 108 and Contra Costa from 34 to 60 over the past seven days.
San Bernardino, San Diego, Riverside and Orange are also seeing steep inclines.
Patient totals are starting to accelerate in the Sacramento area as well, though those spikes appear to have started later than in the Bay Area or Southern California.
In the past week, the number of COVID-positive patients in hospitals has grown from 142 to 179 in Sacramento County, 77 to 90 in Placer County and from 7 to 11 in El Dorado County.
Yolo County, the first in the region to confirm omicron cases as well as two outbreaks – one linked to a West Sacramento high school classroom and another to a workplace holiday party in Davis – had just two patients with the virus, neither in intensive care, as recently as Dec. 16. Yolo hospitals as of Monday were treating 11 COVID-positive patients, including four in ICUs.
Hospitals are not at this time reporting whether hospitalized patients have the omicron variant or delta variant.
Surge disrupts winter travel, holidays, university schedules
The surge has already upended winter plans for many.
Hundreds of flights were canceled nationwide over Christmas weekend, some due to weather but many because COVID-19 infections had left airlines short-staffed.
Most University of California campuses on the quarter system announced last week they would open the winter quarter on a remote-learning basis for the first two weeks of January (UC Davis will transition for one week).
The UC and California State University systems also will require students, faculty and staff members to receive a booster dose when eligible to remain on campus.
And Sacramento city officials this week canceled Friday’s planned New Year’s Eve fireworks show, doing so at public health officials’ recommendations due to omicron.
This story was originally published December 28, 2021 at 12:26 PM.
