The new mutation of the SARS-CoV-2 virus has been called N501Y in the United Kingdom, after an increase in cases of both infections and deaths in the United Kingdom. According to the journal Science, on December 8, scientists and public health experts concluded that the cause of this spike in virus infections was a variant of Covid-19.
Two weeks later, the British Health Minister, Matt Hancock, stated that the new strain of coronavirus detected in England was “out of control” and that is why the Government had had to act “quickly and decisively”, referring to the confinement imposed in London and the southeast of the country.
The British government’s scientific advisor, Patrick Vallance, explained that this variant of SARS-CoV-2, in addition to spreading rapidly, is becoming the “dominant” form of Covid-19. The new strain would have appeared in mid-September in London or Kent, southeast England.
According to the preliminary study on this new virus strain, a distinct phylogenetic group (called the B.1.1.7 lineage) was detected within the COG-UK surveillance data set. This group has been growing rapidly for the past 4 weeks and has since been observed in other UK locations, indicating further and rapid spread.
Of that different group of viruses, a report explained that among the 17 mutations they found, there are eight in the gene that encodes the spike protein on the viral surface, two of which are particularly concerning: one, called N501Y, which increases the The strength with which the protein binds to the ACE2 receptor, its point of entry into human cells.
The other, called 69-70del, leads to the loss of two amino acids in the spike protein and has been found in viruses that elude the immune response in some immunosuppressed patients.
In addition to the United Kingdom, the new variant has also been identified in countries such as Italy, Denmark, the Netherlands and Australia, and given its great contagion capacity, it is likely to emerge in other countries.
Unlike its close relatives, SARS-CoV-2 can easily attack and penetrate human cells at multiple points, with the lungs and throat being the main targets. Once inside the body, the virus uses a diverse arsenal of dangerous molecules to duplicate itself and display its viral load.
Biologists note that among the viruses that attack humans, coronaviruses are among the largest. At 125 nanometers in diameter, they are also relatively large for viruses that use RNA to replicate.
But these explain that coronaviruses really do stand out for their genomes: At 30,000 genetic bases, they have the largest genomes of RNA viruses. They are three times larger than those for HIV and hepatitis C, and more than twice those for seasonal flu.
Coronaviruses are also one of the few RNA viruses with a genomic correction mechanism, preventing the accumulation of mutations that could weaken it. That ability could be why common antivirals like ribavirin, which can thwart viruses like hepatitis C, have failed to subdue SARS-CoV-2.
Drugs weaken viruses by inducing mutations. But in coronaviruses, the proofreader can eliminate those changes.
Being an RNA virus, SARS-Cov-2 enters host cells, replicates genomic RNA, and produces many smaller RNAs (called “subgenomic RNAs”). These subgenomic RNAs are used for the synthesis of various proteins (peaks, envelopes, etc.) that are required for the initiation of the SARS-Cov-2 “lineage” with human cells.
So far, Covid-19 has accumulated mutations at a rate of about one to two changes per month. That means that many of the genomes sequenced today do not match by around 20 points from the first genomes sequenced in China in January, but many variants with fewer changes are also circulating.
“Coronaviruses mutate all the time, so it is not surprising that new variants of SARS-CoV-2 emerge,” recalled Professor Julian Hiscox, from the University of Liverpool. “The most important thing is to try to know if this variant has properties that have an impact on human health, diagnostics and vaccines.”
The biggest unknown today revolves around the vaccines that were developed, says Ewan Birney, deputy director general of the European Molecular Biology Laboratory and co-director of its European Institute of Bioinformatics in Cambridge.
Birney assured The Guardian that vaccines have been tested with many variants of the virus in circulation, therefore there is reason to think that vaccines will still work against this new strain, although this has yet to be thoroughly tested.