The Omicron variant of the coronavirus has expanded its reach in California, with more cases reported in recent days in Los Angeles, San Bernardino and Ventura counties.
Omicron’s spread is one of the factors that led California officials to order a statewide mandate for people to wear masks in indoor public settings that took effect Wednesday.
Los Angeles County has confirmed 15 Omicron cases, including eight new cases on Tuesday. Of the new cases, officials said none of the patients required hospitalization, and seven showed symptoms; it was not known whether the eighth new patient had symptoms. Five of the eight were fully vaccinated, and none had received a booster shot.
Two of the newest Omicron patients survived a previous coronavirus infection. Only one of them traveled internationally; two reported recent out-of-state travel.
“Preliminary data indicates that the Omicron variant is highly infectious and that being fully vaccinated might not provide adequate protection against infection,” the L.A. County Department of Public Health said in a statement. The department “encourages everyone who is eligible for a booster to get one as soon as possible and to continue wearing a mask when in crowded public spaces.”
California’s new mask order affects about half the state’s residents, those who live in counties that do not already have an indoor mask mandate, such as San Diego, Orange, Riverside and San Bernardino counties, as well as wide swaths of the Central Valley and rural Northern California.
The order will last one month and expires on Jan. 15. There will be no changes in Los Angeles or Ventura counties, which already have an indoor mask order.
The disclosure comes as the head of the World Health Organization warned the public against complacency to Omicron.
“Omicron is spreading at a rate we have not seen with any previous variant,” WHO director-general Tedros Adhanom Ghebreyesus said.
“We’re concerned that people are dismissing Omicron as mild. Surely, we have learned by now that we underestimate this virus at our peril,” he said. “Even if Omicron does cause less severe disease, the sheer number of cases could once again overwhelm unprepared health systems.”
San Bernardino County confirmed its first Omicron case on Tuesday. The case involved a man who lives in Redlands who was fully vaccinated and had received a booster shot.
“He had traveled to a conference out of state and returned with COVID-19 symptoms,” the county said in a statement. He is recovering at home.
Pasadena, which runs its own health department separate from L.A. County, confirmed its first Omicron case Monday, in a person believed to have acquired the infection locally earlier this month. “The person was fully vaccinated and had a booster dose, has recovered from a mild illness that did not require hospitalization, and had close contacts who are self-isolating,” the city said in a statement.
Ventura County reported its first Omicron case on Friday, in a fully vaccinated adult who did not need medical care. “A small number of close contacts have been identified and, to date, all have tested negative and have no symptoms,” the Ventura County Public Health Department said in a statement.
Officials in Ventura County warned that its effective transmission number is 1.3 — meaning that every infected person is giving the virus on average to 1.3 other people, resulting in a spread of the virus, rather than a contraction.
“We are experiencing a rapid increase in the spread of the virus that causes COVID-19,” said Ventura County Public Health Director Rigoberto Vargas in a statement. “Given this high and increasing level of community transmission and the possibility of a highly infectious new variant in our county, I urge all Ventura County residents to continue adhering to the measures we know help control the virus: vaccinate, get a booster, wear a mask when indoors in public places or at large outdoor mega events.”
In San Francisco, state officials allowed a slight easing of the statewide mask order. The San Francisco Department of Public Health said that people in certain indoor public settings, like gyms, where everyone is vaccinated will still be able to have the option to not wear masks, and the statewide order will not override San Francisco’s local order allowing for optional mask wearing in this setting.
“This refinement acknowledges the hard work of the people of San Francisco throughout the pandemic, including the ways in which we have maintained reasonable protections heading into the holiday season. This means that stable cohorts of 100% fully vaccinated people in select settings like workspaces and gyms will continue to be allowed to remove masks when the necessary safety measures have been met,” the San Francisco Department of Public Health said in a statement.