University Of California Scientists Warns That California’s B.1.427 And B.1.429 Variants Are More Infectious, Evades Immunity And More Lethal!
Scientists from the University of California-San Francisco are warning the local variants B.1.427/B.1.429 are not only infectious and more transmissible along with the fact that it is immune evasive but rather studies have showed that it causes more severe conditions in those infected with it and is also more deadly.
The B.1.427/B.1.429 variant
that emerged in late 2020 and surged to become the dominant strain in California not only spreads more readily than its predecessors, it also evades antibodies generated by COVID-19 vaccines or prior infection and it’s associated with severe illness and death, the scientists warned.
Following a new research that helps explain the state’s dramatic surge in COVID-19 cases and deaths, and also portends further trouble ahead, the study team said that the cluster of mutations that characterizes the homegrown strain should mark it as a “variant of concern” on par with those from the United Kingdom, South Africa and Brazil.
Dr Charles Chiu, who led the study team of geneticists, epidemiologists, statisticians and other scientists in a wide-ranging analysis of the new variant, which they call B.1.427/B.1.429 told Thailand Medical News, “The devil is already here. I wish it were different. But the science is the science.”
The state of California along with the rest of the country, have been bracing for the rise of a more transmissible coronavirus variant from the U.K. known as B.1.1.7.
However man are unaware that a rival strain that is probably just as worrisome has already settled in, and will probably account for 90% of the state’s infections by the end of next month, said Dr Chiu, an infectious diseases researcher and physician.
Worryingly the U.K. and California variants are each armed with enhanced capabilities, and the likelihood that they could circulate in the same population raises the specter of a return to spiking infections and deaths, Dr Chiu said.
The presence of these new variants also opens the door to a “nightmare scenario”: That the two viruses will meet in a single person, swap their mutations, and create an even more dangerous strain of the SARS-CoV-2 virus.
This alarming new evidence that the California variant could make individuals more sicker, and vaccines less effective, should spur more intensive efforts to drive down infections, Chiu said. Those should include both public health measures, such as masking and limits on public activities, and a campaign of rapid vaccinations, he added.
This new study is currently under review by the public health departments of San Francisco County and the state, which collaborated in the new research.
The study findings are expected to be published in the next few days late this week on the preprint server MedRxiv, a website that allows new research to be shared before it is peer reviewed and formally published in a related journal.
In the last five months starting on Sept. 1, the California strain, which is sometimes referred to as 20C/L452R, rose from complete obscurity to account for more than 50% of all coronavirus samples that were subjected to genetic analysis in
the state. Compared with strains that were most prominent here in early fall, the new strain seems to have an enhanced ability to spread, Dr Chiu said.
Precisely how much more transmissible the California strain is remains an open question, he added. But the evidence that it’s more contagious comes from several sources.
Specimens collected from a range of counties, and using a variety of collection methods, suggest the variant is 19% to 24% more transmissible. But in some circumstances, its advantage was much greater: In one nursing home outbreak, B.1.427/B.1.429 spread at a rate that was six times higher than its predecessors.
Scientists are also discerned uniform patterns of the variant’s expansion in counties across the state. When infection rates rose, they typically did so in tandem with growing evidence of the California strain’s presence.
The B.1.427/B.1.429 variant’s enhanced propensity for spread was also evident in laboratory results. An analysis of viral samples from around the state showed that compared with people infected with other strains of SARS-CoV-2, those who were infected with the California strain had viral loads in the nasopharynx that were twice as high.
Importantly that, in turn, made it highly likely that each person infected with the new strain would go on to infect more people.
The B.1.427/B.1.429’s genome includes three mutations that affect the crucial spike protein, which the virus uses to sneak into human cells and convert them into factories for its own production. One of those three mutations, dubbed L452R, affects to so-called receptor binding domain, helping the virus attach more firmly to target cells. https://pubmed.ncbi.nlm.nih.gov/32730807/
This mutation has not been seen in coronavirus variants that have caused worry elsewhere.
A University of Washington Study has shown that the L452R mutation potentially favors adaptive evolution of SARS-CoV-2. Furthermore that study suggested that the mutation had a much stronger binding to the ACE receptor and escape from neutralizing antibodies. If true, this in turn might lead to significantly increased infectivity of the L452R variants, warranting their close surveillance and in-depth functional studies. https://www.biorxiv.org/content/10.1101/2021.02.22.432189v1
The University of California-San Francisco scientists found that the L452R mutation alone made the California strain more damaging as well. A coronavirus engineered to have only that mutation was able to infect human lung tissue at least 40% more readily than were circulating variants that lacked the mutation. Compared with those so-called wild-type strains, the engineered virus was more than three times more infectious
Furthermore in the lab, the California strain also revealed itself to be more resistant to neutralizing antibodies generated in response to COVID-19 vaccines as well as by a previous coronavirus infection. When compared with existing variants, the reduction in protection was “moderate ... but significant,” the scientists said.
The VOC (variant of concern) B.1.351 or 501.V2 coronavirus strain that’s now dominant in South Africa and that has raised concerns about evading the immune system’s defenses has been shown to reduce the effect of neutralizing antibodies by a factor of 6.2. With the California strain, the effect of these antibodies was reduced by a factor of two.
Dr Chiu commented, “I do anticipate over time it is going to have an effect on vaccination. Though the magnitude of the effect varied from sample to sample and was less pronounced than with the South Africa strain, it still is concerning.”
Significantly, the new study also suggested the California variant could have greater virulence.
This observational conclusion was based on the medical charts of 324 patients hospitalized at University of California-San Francisco,
a relatively small sample.
Despite the small sample size, the researchers found that the 21% of these patients who were infected with B.1.427/B.1.429 were more likely than their counterparts to have been admitted to the ICU, and they were 11 times more likely to die. That finding held up even after researchers adjusted for differences in the patients’ age, gender and ethnicity.
The study team said that that this increased risk of death may be a sign that the variant is inherently more lethal. Also it may simply be a reflection that its greater transmissibility caused hospitals to become so overwhelmed and healthcare resources to be stretched so thin that more deaths were the result especially in Southern California.
An expert on infectious disease tracking at University Of California-Los Angeles (UCLA), Dr Marc Suchard who was not involved in the UCSF work said that some of the team’s findings will probably be refined as more virus samples are genetically sequenced and more data come to light.
Dr Suchard said, “It remains critically important that we actively sequence the virus as cases are diagnosed in our state. I am glad to see such collaboration between academics and public health departments in California to identify the emergence of a previously unidentified lineage.”
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