How a new COVID strain emerged in California, and what it means for getting out of the pandemic

COVID-19 mutations have emerged in the UK, South Africa, Brazil and California. Researchers at Cedars-Sinai Medical Center say a variant that originated in this state accounted for half of all virus samples collected in LA labs last week.

Jasmine Plummer is one of the researchers at Cedars-Sinai  who discovered the CAL.20C variant. She says, "We were looking, actually, for the UK variant, knowing the UK variant was likely in California. We saw that it emerged — there was only one out of 1,230 [samples that looked like CAL.20C] in July."

The presence of the variant increased starting in October and continued through the holidays, and by January 13 CAL.20C accounted for half of all virus samples collected in LA labs, according to the study.

"We allowed it to emerge over the holidays, and that really is not separable from our behavior," Plummer says. "And so the same thing applies that applied in March. ... If it is more infectious, and it can be easily transmitted, it's really simple: We can wear a mask, wash our hands, and socially distance."



  • Jasmine Plummer - research scientist and molecular geneticist at Cedars-Sinai Medical Center