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A terrifying new strain of coronavirus, innocuously named B.1.1.7, has recently erupted in south-east England, prompting the government to tighten blockades in the region. Although we do not know all the details, experts are increasingly confident that it is transmitted more easily than other strains. Here is everything we know so far about this new strain.
What is it?
The SARS-CoV-2 strain B.1.1.7 is a version of the virus with 23 mutations, eight of which are in the spike protein that the virus uses to bind to and enter human cells. Science Magazine reported.
Where he came from?
It was first detected on September 21 in the county of Kent in England, then took off and spread in November. according to the World Health Organization.
Since then, it has become the most common variant in England, accounting for more than 50% of new cases diagnosed between October and December 13 in the UK, according to the WHO.
However, some scientists now believe that the virus may have mutated in an immunosuppressed person, according to Science magazine. This is because, unlike the flu, the new coronavirus can correct errors when it replicates and thus tends to have a fairly stable genome, Live Science previously reported. However, studies have shown that people who have weakened immune systems, because they are taking immunosuppressive drugs or being treated with chemotherapy, for example, can harbor infectious viruses for months. That, in turn, would give the virus many opportunities to acquire mutations that help it replicate or evade the virus. immune system.
What do these mutations do?
We do not know for sure. Viruses mutate all the time and most of these changes do not affect the mortality or infectivity of the virus. In this case, some of these mutations may have arisen by pure chance and may not affect the function of the virus.
But three mutations in particular have worried experts.
One, a two amino acid deletion known as 69-70Delta, was first detected separately in a patient on immunosuppressants who developed COVID-19. The patient received remdesevir, convalescent plasma, and neutralizing antibodies, but died months later. Although the virus did not initially have this deletion, it acquired it for months, the researchers reported in a pre-printed article published Dec. 19. withRiv database. (It has not been peer reviewed). The authors suspect that it evolved to evade the immune system. Another wrinkle associated with this removal is that it can cause one of the targets of SARS-CoV-2 PCR tests, known as the S gene, to give a false negative. Some tests only look for positives in this S gene and therefore would lose the new variant. Most PCR assays, however, look for three separate regions of the spike protein, so those assays will not be affected, the WHO said.
Another mutation, known as N501Y, alters the key amino acids that make up the so-called receptor-binding domain of SARS-CoV-2, where the amino acid asparagine (N) has been replaced by tyrosine (Y) in the part of the virus that attaches itself. to the ACE2 receptor of human cells, according to the Centers for Disease Control and Prevention. A September study in the journal Cell found that this variant binds more closely to the ACE2 receptor than other versions of the coronavirus, at least on a lab plate.
Dozens of SARS-CoV-2 samples from South Africa and Australia tested positive for this mutation, but laboratory tests suggest that the South African and UK variants separately developed the same mutation. That suggests it may provide an evolutionary advantage to the virus.
The third suspicious mutation is P681H, which is also in the receptor-binding domain of the virus. According to preliminary information published by the COVID-19 Genomics Consortium UK, this mutation is found next to the “furin cleavage site”, which is where the spike protein must be cleaved for the virus to enter cells, according to Science magazine.
Does it spread more easily?
Yes. Experts now believe that the new variant is between 50% and 74% more transmissible than other dominant strains, according to a study by the Center for Mathematical Modeling and Infectious Diseases (CMMID) which has not yet been peer reviewed. The WHO estimates that this would add 0.4 to the basic reproductive number R, which dictates how many people each infected person would transmit the virus to.
Based on models of that growth, the new variant could be responsible for 90% of all new COVID-19 cases in London and the east and south of England by mid-January, according to the study.
Is it more deadly?
We don’t know, but experts suspect not. However, if it spreads much more easily, that means more people will be hospitalized. Once hospitals are overwhelmed, the quality of care for the sickest patients declines, which can lead to higher death rates than would otherwise be expected.
The CMMID study found that the new variant could explain an increase in hospitalizations in south-east England, largely due to further spread, not necessarily because the virus is more dangerous.
Another study, also not peer-reviewed, conducted by CMMID, used a mathematical model to see whether the rapid growth of the virus in London was due to increased infectivity or was more severe. The latter did not fit well with the data, while the former did not fit well.
Has the variant been extended to the US?
So far, scientists have not detected this strain anywhere in the US, although the US has not done as much genetic sequencing on viral samples as the UK. For example, as of December, the US had sequenced 51,000 viral samples from 17 million identified cases of SARS-CoV-2, According to the Centers for Disease Control and Prevention. The UK has sequenced more than twice as many viral samples as the US, despite having just over a tenth of diagnosed cases.
Dr. Stanley Perlman, Immunologist and Pediatric Infectious Disease Specialist at the University of Iowa told the Center for Infectious Diseases Research and Policy (CIDRAP) that suspects the variant is already in the United States “I’d be surprised if it wasn’t,” he said.
Can children get it more easily?
Several lines of evidence in the past have suggested that children may be less susceptible to the new coronavirus. If this new variant sticks more easily to cells, there is a chance that it will spread more easily among children than before. However, more studies will be needed to see if that is the case.
There has been a uptick in cases in children in England at the same time that this virus has increased its prevalence. That spike was not seen when children returned to schools in the early fall. But schools were open while a lot of other things were closed right now, so it’s possible that schools represented one of the relatively few chances that the virus would spread. We still cannot say that children grasp and propagate this variant more easily.
Will vaccines against the new virus work?
Most experts believe that newly developed vaccines will continue to work against the new UK variant. When vaccines stimulate the immune system, the body builds an arsenal of cells to bind to many different parts of the virus. Mutations in a handful of points are likely not enough to make the vaccine less effective, according to the CDC.
Since 99% of the proteins in the new variant are identical to the strain targeted by the Pfizer-BioNtech mRNA vaccine (the Moderna vaccine is very similar), the vaccine is very likely to work, said the CEO. from BioNTech, Uğur Şahin, in a news story. instructions.
It is possible that, over time, a variant will emerge that bypasses some of our vaccines, similar to the way the flu vaccine must be updated each year. However, new mRNA vaccines could be updated to reflect new mutations in about six weeks, Şahin told the Financial Times.
What can we do to stop this?
The new variant is still spreading in the same way as the ordinary form of the coronavirus. That means the same things everyone has been doing to prevent the spread of the virus since March will also work for the new UK variant: hand washing, physical distancing, masks and good ventilation. Strictly adhering to those rules and avoiding unnecessary exits will help prevent their spread.
Originally posted on Live Science.
