Omicron cases jump in L.A. County as experts warn of rapid spread

The number of Omicron cases in Los Angeles County rose to at least 30, officials said Thursday has they continued to urge vaccinations and booster shots to slow the spread.

Officials confirmed 12 new cases Thursday, saying the spread will likely intensify in the coming weeks.

Of the 30 total Omicron cases in L.A. County, 24 people were fully vaccinated and four had also received booster doses. None have been known to be hospitalized, and none have died.

Nationally, more than 300 Omicron cases have been confirmed, and at least 49 in California.

Health officials have begun to warn that Omicron may pose a threat to hospitals in the coming weeks, due to its explosive spread. Even if it does pose a risk for less severe disease in general, the sheer increase in its transmissibility could still result in hospitals being overwhelmed.

"Given what we know, Omicron does pose a significant threat to our community in L.A.," county Public Health Director Barbara Ferrer said Thursday. "Unvaccinated individuals appear to remain at the highest risk. But all the evidence to date indicates that those fully vaccinated are also at increased risk, particularly for getting infected and infecting others."

That's why it's so important that fully vaccinated people get booster shots, and why it's important to get tested before attending holiday gatherings, as vaccinated asymptomatic people can potentially be infected and spread the virus to others.

Early data suggest that effectiveness against symptomatic illness from Omicron for the two-shot Pfizer-BioNTech vaccine falls to 35% but rises to 75% following a booster shot. Still, this is not as good as the vaccine effectiveness against Delta, which was 95% following the booster, according to Dr. Eric Topol, director of the Scripps Research Translational Institute in La Jolla.

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.

Dr. Rochelle Walensky, the director of the U.S. Centers for Disease Control and Prevention, said Omicron nationally is now accounting for 3% of analyzed coronavirus cases but is substantially higher in some locations. In the New York and New Jersey areas, Omicron is estimated to comprise 13% of new cases.

Dr. Anthony Fauci, President Biden's chief medical advisor for the pandemic, said Thursday that he anticipates Omicron will become the dominant variant soon.

"It has an extraordinary ability to transmit efficiently and spread. It has what we call a doubling time of about three days," Fauci said on ABC's "Good Morning America." "And if you do the math on that, if you have just a couple of percentage of the isolates being Omicron, very soon it's going to be the dominant variant. We've seen that in South Africa. We're seeing it in the U.K., and I'm absolutely certain that's what we're going to be seeing here relatively soon."

Globally, health officials and experts are warning against being complacent about Omicron, based on early reports suggesting it may cause milder illness. Even if the strain really is less likely to cause severe illness for a particular person, because the variant is far more contagious, many more people could end up getting infected and hospitals could be overwhelmed anyway.

Topol suggested that those who suspect Omicron won’t be a big deal are in denial.

“For the pandemic, the U.S. has invented the 5 denials of warnings (it won’t happen here),” Topol wrote in a tweet. He said there is ample “alarming Omicron signals” coming from several countries, including South Africa, Denmark and Norway.

The state is already dealing with a post-Thanksgiving surge of COVID-19 cases from the Delta variant.

California’s COVID-19 hospitalizations have hit their highest number in more than a month. Over the last three weeks, COVID-19 hospitalizations statewide have risen by 16%, from 3,109 patients in hospitals on Nov. 23 to 3,613 as of Tuesday.

The increase has been dramatic across Southern California. Since Nov. 23, COVID-19 hospitalizations have risen by 49% in Ventura County, 47% in San Diego County, 39% in Los Angeles County, 36% in Riverside County, 26% in San Bernardino County and 15% in Orange County.

This story originally appeared in Los Angeles Times.