Researchers to follow Coronavirus mutation I spent a week scrutinizing the details of the new variants found in Botswana this month.
This is the latest in an ever-growing number of over 1,500 recognized strains of the Sars-Cov-2 virus that have emerged since the beginning of the pandemic. As a sign of anxiety about threats from new variants, on Thursday night the UK and Israel issued a travel ban to groups of countries in southern Africa in response to the unusually high spike mutations in the new B.1.1.529 strain. I imposed.
Even more contagious, more deadly, or even vaccine-resistant strains Dominant delta variant, What emerged in India at the end of last year is vigilant to scientists and health authorities.
“Did Sars-Cov-2 try all the tricks? Gavin Screaton, an immunologist and director of medicine at Oxford University, said:
The virus is constantly changing. Each replication causes a new error in the 30,000 nucleotide string that makes up the genome.
Normally, these mutations disappear, but each one is unlikely to be more suitable for the virus, increasing viral load, facilitating binding to cells in the respiratory tract, and bypassing the body’s immune defenses. There is likely to be.
Before Delta, the biggest threat was An Alpha variant that is rapidly gaining popularity in the United Kingdom. A dozen strains are classified by the World Health Organization as a variant of “concern” or “interest” and have the official Greek alphabetic name. The latest is the Mu variant that emerged in Colombia in January.
Last month, UK authorities began monitoring Delta subvariants, which could increase infection rates by about 10%. Two more Delta descendants recently discovered in Canada and Indonesia share similarities with this strain.
Emma Hodcroft, an evolutionary geneticist at the University of Basel and one of the first to track mutations, said: “But the virus is always looking for the next move.”
There is more than one reason why more dangerous mutants did not emerge, but experts agree that global vaccination campaigns have helped delay mutations.
Prior to the deployment of the vaccine, the virus faced a “simpler immune environment,” susceptibility to almost everyone, and “contagious was the easiest victory,” Hodcroft explained.
With a global initial dose of over 53% and about 30 million jabs administered daily worldwide, the next move for the virus was “less cut and dry.” “It could be more contagious and find a way to avoid the immune response-or both,” she said.
Some say that the transmission rate has already peaked. François Barrow, director of the University College London Genetics Institute, said R0 (a fully exposed population) of the prevalent coronavirus before Sars-Cov-2 peaked at 7 after decades of natural choice. The number of reproductions in London) was stated.
Delta’s R0 is between 6 and 7, which is more than double that of the original Wuhan strain, so the predominant mutant “has little room for increased infectivity in the short term,” he said. ..
Balloux predicted that Sars-Cov-2 would fall into a pattern of “slow evolution around the immune system” over a decade, rather than a “continuous surge in infectivity.” The same, elicited evolution can be observed with influenza and seasonal coronavirus.
However, scientists continue to be concerned about sudden viral mutations, causing a global pandemic reaction and vaccination off course.
The B.1.1.529 strain, which is widespread in South Africa and Botswana, raises concerns for this reason, as many of its 32 mutations are associated with the ability to evade the immune system and spread faster.
WHO convened an emergency meeting on Friday and is expected to classify this strain as a mutant strain of interest, according to one person with knowledge of the issue.
Triode Oliveira, director of the South African Epidemic Response and Innovation Center, is “worried” about this variant, due to about 90% of the approximately 1,100 virus cases registered in Gauteng on Wednesday. Said. Abnormally, he said, strains can be detected by analyzing the results of routine PCR tests without using genomic sequencing.
“The important question to be answered is exactly what. [variant’s] Impact on vaccines, “he added.
Slawomir Kubik, a Genomics research expert at Sophia Genetics, a biotechnology based in Geneva, emphasized that the “fitness” of a mutant can only be determined by the way it “spreads in the real world.”
“It’s about genes, the environment, and the degree of luck … If you have a” favorable “mutation, but never inherit it, it will never spread,” he said. ..
Even if the Botswana strain declines, other strains will emerge. Venky Soundararajan, chief scientist at data analysis firm Nference, was concerned that the effects of the inoculation drive could push the virus into a “genetic dead end” and create an “escape variant” that could evade the immune system.
“Vaccines are a gift from God in their ability to stop infections and severe illnesses, but paradoxically, they also increase the need to monitor these highly specific targeted mutations,” he said. ..
Soundararajan warned that the unequal distribution of sequencing technology created a “gap hole” in genome surveillance. Over 80% of the 5.4 million Sars-Cov-2 genomes uploaded to the Gisaid Global Repository are from two continents, North America and Europe.
No one knows when and where the dominant mutant will appear, but there is a scientific consensus that Delta will not remain dominant forever.
Kevin McCarthy, a professor of microbiology and microbiology at the University of Pittsburgh, said the evolution of the virus was “approaching a turning point,” after which the odds would favor the escape variant.
“Does the virus move to something that alters its antigenicity and compromises the effectiveness of the vaccine? I think it’s likely to happen,” he said. “When faced with the dual choice of evolving or extinct a virus, it evolves.”
“Viruses are always looking for the next move”: why science is wary of new variants
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