21-12-2020 by Mirai
The SARS-CoV-2 coronavirus N501Y mutation was identified in mid-December in the UK. According to the British Prime Minister, it could be "up to 70% more contagious than the previous strain." Scientists ask for caution.
London and the southeast of England will spend the end of the year celebrations in lockdown. On Saturday, December 19, British Prime Minister Boris Johnson decided to reconfigure part of the country, less than two weeks after the partial deconfinition of December 3. The UK is facing an increase in the number of new Covid-19 cases.
The resumption of the epidemic would be driven by "a new variant of the coronavirus" that "seems to spread more easily and could be up to 70% more contagious than the previous strain," said the head of the British government during a press conference.
Residents are told to stay home, non-essential businesses are closed and travel (to travel abroad or within the UK) is banned from December 20.
The circulation of the SARS-CoV-2 strain N501Y in the UK was revealed on Monday, December 14, by British Health Minister Matt Hancock. This mutation, which appeared in mid-September, in London or Kent, is on its way to becoming the "dominant" strain in the south of England. According to Patrick Vallance, scientific advisor to the British government, it is the cause of 62% of the contaminations recorded in December in London and 43% of the contaminations recorded in the South East (compared to 28% in mid-November).
"N501Y was already circulating sporadically earlier this year outside the UK, in Australia in June-July, in the US in July and in Brazil in April," noted Dr Julian Tang (University of Leicester). It has been detected by the British COG-UK consortium that is studying the coronavirus genome among positive test samples to identify its variants and their geographical distribution.
Outside of British territory, the World Health Organization lists nine cases in Denmark, one case in the Netherlands and one in Australia. Italy also announced a first case detected on Sunday. "Throughout Europe, where transmission is high and widespread, countries must strengthen their control and prevention procedures," the UN organization said in a statement.
Why and how has the SARS-CoV-2 coronavirus mutated?
Coronaviruses mutate regularly: "After infecting our cells, they multiply by making copies of themselves. This process is not perfect and the copies may contain errors: the famous mutations. However, like other coronaviruses, SARS-CoV-2 is quite stable because it has an enzyme that corrects these errors (an exoribonuclease), "says Inserm on its website.
According to Patrick Vallance, the new SARS-CoV-2 variant differs from the "model" virus by 17 points, an "unusually high" number. Most are said to be "associated with changes in the protein that the virus makes" and "the way the virus binds to or enters cells," he said. The main fear to date is that the disease will spread more quickly.
Is the newest variant of SARS-CoV-2 more dangerous?
Scientists do not yet have enough data to know if the N501Y mutation induces more severe or more contagious forms of Covid-19. On Saturday, December 19, the British Prime Minister also indicated that it was too early to measure the impact of this discovery on the effectiveness of vaccines.
An article published in the British Medical Journal on Wednesday indicates that there is currently no way to establish a causal link between the increase in Covid-19 cases and the circulation of the N501Y strain. Containment is necessary as a precautionary measure, but we cannot know if the number of new contagions has started to increase again due to the release of the population or due to a potentially more contagious strain.
For its part, the World Health Organization (WHO) does not recognize "any evidence of a change in the severity of the disease" at this stage. However, in view of the "preliminary" information, it is concerned that the UK variant may "affect the effectiveness of certain diagnostic methods". Asked by CNN, Englands chief medical officer Chris Witty says that work has begun "urgently" to determine whether or not the mutation of the virus can lead to a higher death rate or whether it affects the effectiveness of treatments. and vaccines.
"There is currently no evidence that this variant (or any other variant studied to date) has an impact on the severity of the disease, or that it makes vaccines less effective, although these two issues require further study.", Says the COG-UK consortium.
Same observation by the European Medicines Agency (EMA) that authorized, on Monday, December 21, the marketing of the Pfizer-BioNTech vaccine. According to the European regulator, "there is no evidence" to suggest that the Pfizer-BioNTech vaccine does not protect against this new strain of coronavirus.
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