Coronavirus US: what is the Californian strain; is it more dangerous and contagious?

While the variants of covid-19 coming from the UK, Brazil and South Africa have been getting all the attention, there has been a concerning strain quietly developing and spreading in California.

The new variant, which scientists refer to as B.1.427/B.1.429, which came on the radar in September 2020 is thought to spread more quickly than others. According to a limited but worrying new study there are now concerns that it could be better at dodging antibodies created by previous infection or a vaccine, and may cause more serious illness.

But is it really a cause for concern?

What’s causing the alarm over the California variant?

“This variant is concerning because our data shows that it is more contagious, more likely to be associated with severe illness, and at least partially resistant to neutralizing antibodies,” says Charles Chiu, an infectious diseases physician and sequencing expert at University of California, San Francisco (UCSF) who is the senior author of a preprint reporting lab studies and epidemiological data.

The data suggest the new strain “should likely be designated a variant of concern warranting urgent follow-up investigation,” the authors write in their preprint, which has not been peer reviewed and which they say is expected to be posted online soon. "The devil is already here" Chiu told the LA Times.

In other words, there is limited proof that the new strain found in California is more resistant to antibodies and more likely to cause serious illness or fatalities.

On the subject of vaccine efficacy, Chiu went on to tell the Times that "if we can get enough people vaccinated, we will be able to deal with these variants simply because we won't have ongoing transmission."

The same mitigation measures apply to new variants as the original coronavirus strain: wear a mask, socially distance and do not spend time indoors with people outside of your household.

Other scientists more cautious on California strain

However, Science Mag this week reported that other coronavirus experts say more data is needed before real conclusions are drawn, noting that among patients with the variant, the study included fewer than 10 who were admitted to the ICU and fewer than 10 who died.

“If I were a reviewer, I would want to see more data from more infected people to substantiate this very provocative claim,” says David O’Connor, a viral sequencing expert at the University of Wisconsin, Madison, who was not part of the research.

"I'm increasingly convinced that this one is transmitting more than others locally," William Hanage, an epidemiologist at the Harvard T.H. Chan School of Public Health who was not involved in the research, told The New York Times, with reference to the highly contagious variant found in the UK Hanage added "But there's not evidence to suggest that it's in the same ballpark as B.1.1.7."

For their study, the authors sequenced 2172 genomes from virus samples captured from 300 patients in 44 California counties between 1 September 2020 and 29 January 2021.