Jan. 20, 2021 -- After 2 months of record-breaking numbers, COVID-19 cases appear to be flattening across California. But now, a new worry has emerged: A California-specific variant of the coronavirus.

Three previously identified variants have been termed "variants of concern" because each contains clusters of mutations that appear to make the virus more contagious and may help it evade the body's immune defenses. These were first identified in the U.K. and South Africa, with the third showing up in Brazil and Japan.

The California variant, and some others that have recently been identified circulating in Ohio and near Houston, are still under study. Viruses mutate all the time. During the pandemic, the coronavirus has changed itself many times. These variants can become a problem if they’re better at infecting humans and if they create defenses against vaccines.

Studies show the new variant became more common in California as cases there surged. The coincidence has researchers wondering whether it might be responsible for the recent rise in cases, though more study is needed.

Cedars-Sinai hospital in California says its researchers have identified five coronavirus mutations as part of what’s called the CAL.20C strain of the virus.

Eric Vail, MD, director of molecular pathology in the Department of Pathology and Laboratory Medicine at Cedars-Sinai, along with colleagues, found that the CAL.20C strain was identified in 36.4% of cases in Los Angeles.

"The recent surge in COVID-19 positive cases in Southern California coincides with the emergence of CAL.20C," Vail said in a statement.

He and colleagues have written a study of their findings that has yet to be analyzed or published by other researchers. It has been submitted to a preprint server, and it was also submitted for peer review on Jan. 14, the hospital said.

According to the Los Angeles Times, one of the CAL.20C variants, which was first noticed in Denmark in March, has been in California as early as May.

The Times reports that cases of this variant confirmed by genetic analysis have increased from 4% of samples studied in November to 25% between mid-December and early January.

Still, while the number of appearances of the variant have increased, it’s still unclear whether this mutation will amount to much.

“This is why it’s concerning,” Charles Chiu, MD, a virologist and professor of laboratory medicine at the University of California, San Francisco, told reporters. “It is concerning that it may potentially be more infectious.”

The researchers at Cedars-Sinai found the umbrella strain, CAL.20C, in multiple samples from California, New York, Washington, D.C., and overseas.

What the prevalence of CAL.20C means for the future of the pandemic is yet to be understood, said Wenjuan Zhang, PhD, an assistant professor in the Department of Pathology and Laboratory Medicine at Cedars-Sinai.

The hospital’s research team is "not sure what the new findings mean in terms of the infectivity and antibody resistance of the CAL.20C strain, which is important for follow-up studies that will need to be completed," she said.

WebMD Health News Brief

Sources

Cedars-Sinai: “Local COVID-19 Strain Found in Over One-Third of Los Angeles Patients.”

Los Angeles Times: “More contagious COVID-19 variants bring new uncertainties to California.”

© 2021 WebMD, LLC. All rights reserved.