New coronavirus strain in UK
Why in News?
- India suspended all flights from and to the UK until December 31, amid concerns about a new variant of SARS-CoV-2 that is “spreading & growing rapidly” there. Several other countries, too, have suspended UK flights and imposed travel restrictions.
What are these concerns leading to travel restrictions?
- Recently, the new SARS-CoV-2 variant was revealed to be the reason behind the rapid surge in Covid-19 cases in South and East England.
- It is being referred to as VUI (Variant Under Investigation) 202012/01, or the B.1.1.7 lineage.
- It is not the first new variant of the pandemic virus to emerge, but is said to be up to 70% more transmissible than the previously dominant strain in the United Kingdom.
What is the variant like?
- The variant is the result of multiple mutations in the spike protein of the novel coronavirus SARS-CoV-2, as well as mutations in other genomic regions of the RNA virus.
- Preliminary analysis suggests that it is more transmissible than previously circulating variants.
- The variant was identified in genomic surveillance by COVID-19 Genomics UK (COG-UK), a consortium that analyses genome sequencing data from the UK.
- COG-UK identified one of these mutations as “N501Y”, in an area of the spike protein that binds to a key protein in the human cell, the ACE2 receptor.
- This was an indication that the alterations may, theoretically, result in the virus becoming more infectious.
Are the concers justified?
- Most scientists say yes.
- The new variant has rapidly become the dominant strain in cases of COVID-19 in parts of southern England, and has been linked to an increase in hospitalisation rates, especially in London and in the adjacent county of Kent.
- While it was first seen in Britain in September, by the week of December 9 in London, 62% of COVID-19 cases were due to the new variant. That compared to 28% of cases three weeks earlier.
But why is it ‘extremely concerning’?
- The main worry is that the variant is significantly more transmissible than the original strain.
- It has 23 mutations in its genetic code — a relatively high number of changes — and some of these are affecting its ability to spread.
- Scientists say it is about 40%-70% more transmissible.
- As per U.K. government, it could increase the reproduction “R” rate by 0.4.
Will COVID-19 vaccines protect against this variant?
- There’s no evidence that vaccines currently being deployed in the U.K. — made by Pfizer and BioNtech — or other COVID-19 shots in development will not protect against this variant.
- COVID-19 vaccines appeared to be adequate in generating an immune response to the variant of the coronavirus.
Does the new variant affect testing?
- To some extent, yes.
- One of the mutations in the new variant affects one of three genomic targets used by some PCR tests.
- This means that in those tests, that target area, or “channel”, would come up negative.
- Since PCR tests generally detect more than one gene target, however, a mutation in the spike protein only partly affects the test, reducing that risk of false negative results.
Are there other significant SARS-CoV-2 variants?
- Strains of the COVID-19-causing virus have emerged in recent months in South Africa, Spain, Denmark and other countries that have also raised concern.
- However none, so far, has been found to contain mutations that make it more deadly, or more likely to be able to evade vaccines or treatments.
THE HINDU, IE
