Los Angeles County is experiencing a rise in new coronavirus infections, a concerning trend given the continued circulation of the highly transmissible Delta variant, officials say.
As of Thursday, 245 Delta cases had been confirmed countywide — double the number last week.
Officials say the variant, which may be twice as transmissible as the conventional coronavirus strain, has the potential to spread rapidly among unvaccinated segments of the population.
And though L.A. County’s overall coronavirus metrics remain relatively low, any increases in transmission have the potential to spur more infections, illness and death in a region already familiar with the suffering COVID-19 can cause.
“The rising proportion of Delta among sequenced variants of concern is consistent with what other parts of the U.S. are seeing, and for certain represents increased circulation of the variant,” Public Health Director Barbara Ferrer said. “Given that 4 million residents in L.A. County are not yet vaccinated, the risk of increased spread is very real.”
Dr. Rochelle Walensky, director of the U.S. Centers for Disease Control and Prevention, said an estimated 25% of new coronavirus cases sequenced nationwide are now of the Delta variant, and she expects it eventually will become the dominant strain in the nation.
“As the Delta variant continues to spread across the country, we expect to see increased transmission in these communities unless we can vaccinate more people now,” she said.
California officials repeated that view.
“The risk for COVID-19 exposure and infection will remain in California until we reach community immunity with vaccinations,” said Dr. Tomás Aragón, director of the California Department of Public Health and the state’s public health officer. “COVID-19 vaccines provide excellent protection from serious disease, even for the Delta variant.”
Circulation of the variant has increased rapidly since it appeared in California.
Delta made up just 1.8% of coronavirus cases analyzed in April, state public health data show.
That proportion jumped to 4.7% in May. As of last week, the variant made up 14.5% of specimens sequenced during June.
On Tuesday, Aragón said the variant accounted for about 23% of sampled cases, “and we anticipate this percentage will increase.”
“We have enough risk and enough unvaccinated people for Delta to pose a threat to our recovery,” Ferrer told reporters Thursday. “And masking up now could help prevent a resurgence in transmission.”