A decoration in California that has spread widely across much of the state since the beginning of the year appears to be more contagious than other versions of the coronavirus, and can also cause serious illness and, according to the body’s immune response, some resistance. offer. to two studies released Monday.
The studies from UCSF and the Chan Zuckerberg Biohub are the first to show that the so-called California variant spreads more easily than other and other worrying traits. Scientists suspected that the variant was more contagious based on how fast it exploded in parts of the state, and because it was linked to several major outbreaks, but so far they have had no evidence.
Scientists from the Chan Zuckerberg Biohub and UCSF looked at positive test results in the Mission District and found that about 35% of household members became infected when one case of the California variant was brought into the home; the attack rate for other variants was about 26%. The variant also quickly became more common in the Mission. Genomic sequencing found the variant in more than half of all samples in January, compared to 16% in November.
Separately, a study by dr. Charles Chiu at UCSF also found evidence that the variant is more contagious. In addition, his team found that people infected with the variant were more likely to end up in intensive care or die. And laboratory tests have shown that the variant responds less to antibodies produced by previously infected people. From the results, it is not clear whether the variant responds less to vaccines.
This ‘should probably be a variant of concern that justifies urgent follow-up investigation,’ Chiu and a team of authors wrote in a paper on the study. Both studies have not yet been published.
“We do not want to sound the alarm. It is not as aggressive as the British variant, ”said Joe DeRisi, co-president of Biohub, about the results of the Mission District study. The variant of the United Kingdom, known as B.1.117, is thought to be about 50% more contagious than the original virus from China. ‘But it emphasizes the need to examine this tribe more closely and do more studies on it. We need to be aware that it is in the community and is spreading fast. ”
Coronavirus variants have become a growing source of concern in the pandemic as mutated versions of the virus emerge around the world that are more contagious, cause serious diseases, or are partially resistant to vaccines. Public health officials are rushing to vaccinate large parts of the country, in part to dispel cases and prevent the virus from further mutating.
Infectious diseases first became concerned about the California variant in January, when two teams of scientists – one at UCSF and one in Los Angeles – independently identified it spreading rapidly in a few communities, including some in the Bay Area. The variant was found to be the source of a major outbreak in Kaiser Permanente in San Jose in which more than 90 people were infected.
There was confusion about what might be called the California variant, which could be two separate but very similar variants that have the same key mutations. The California Department of Public Health refers to them as B.1.429 and B.1.427, but both variants are also called CAL.20C or sometimes with a single mutation, L452R.
This mutation is the key to the California variant. It is located on the vein protein – a place on the virus where it attaches to human cells. Due to its location, it is thought that the L452R mutation could better bind the virus to human cells, making the variant more contagious.
The Mission District research was coordinated by Unidos and Salud, a collaboration between Chan Zuckerberg Biohub, UCSF and the Latino Task Force for COVID-19. The group has been operating a rapid coronavirus test site in the Mission District since August, and scientists have worked with the community to report on how the virus spreads there.
Erin Allday is a staff writer for the San Francisco Chronicle. Email: [email protected] Twitter: @erinallday