Well-Being Medical Advances

California coronavirus variant is more contagious, new research shows

Story at a glance

  • A potentially homegrown mutation of the COVID-19 spike protein could be the reason behind high case numbers in California.
  • The strain, known as CAL.20C, contains changes in the spike protein’s binding receptors, making it potentially more transmissible.

Adding to the recently discovered, more transmissible strains of the coronavirus, a new California variant of the virus has been detected, and data suggests that it is more contagious than the original virus. 

The California variant is spreading throughout the state rapidly, and is likely to have emerged in Southern California, according to research published Feb. 11 in the JAMA medical journal. The strain, dubbed CAL.20C, was reportedly first observed by scientists back in July 2020 during the summer COVID-19 outbreak.

Since then, the prevalence of CAL.20C infections has increased in the state as a whole, accounting for approximately 35 percent of all California COVID-19 cases, and 44 percent of all samples sourced from Southern California counties as of January.

Data reported in the U.S. Centers for Disease Control and Prevention (CDC) website reveals CAL.20C’s frequency among California COVID-19 cases has risen steadily since September.

Similar to other new strains, there are three mutations in the CAL.20C spike protein, which alters the binding receptors, making them more resistant to antibodies produced to fight the virus.

This mutation prompts the question as to whether or not vaccines made to target the binding receptors seen in the original COVID-19 spike protein will be effective against newer forms of the virus.

Questions surrounding COVID-19 vaccines’ efficacy against new strains have yet to be decidedly answered, but CAL.20C appears to be more contagious. The Washington Post writes that as of Thursday, COVID-19 infections prompted by CAL.20C compose over half of infections across 44 California counties. 

Following record-high peaks of new cases, hospitalizations and deaths that occurred over the holiday season, new COVID-19 cases are finally trending downward, including in California.

With the circulation of multiple new strains of COVID-19 from all over the world occurring, scientists are working to see how these mutations will impact the future of the pandemic.

“Fundamentally, it doesn’t change the direction we are going, which is we want to hold cases down to where we can get the pandemic under control. Simply having a more infectious variant circulating is not going to be the end of the world,” Charles Chiu, a professor of laboratory medicine and infectious diseases at the University of California at San Francisco School of Medicine, told The Post. Chiu is one of the lead scientists behind the research into COVID-19 mutations. 

Public health officials in California continue to recommend familiar public health protocols, including wearing masks outside of the home, maintaining physical distances, washing hands and getting vaccinated when available.