The so-called ‘UK variant’ of the coronavirus SARS-CoV-2, which was discovered in Kent and swept across the UK last year before spreading worldwide, is between 30% and 100% more deadly than previous strains, new analysis has shown.
Epidemiologists from the Universities of Exeter and Bristol compared death rates among people infected with the new variant and those infected with other strains. They found that the new variant, B.1.1.7, led to 227 deaths in a sample of 54,906 patients – compared to 141 among the same number of closely matched patients who had the previous strains.
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The University of Exeter quoted lead author Robert Challen as saying: “In the community, death from Covid-19 is still a rare event, but the B.1.1.7 variant raises the risk. Coupled with its ability to spread rapidly, this makes B.1.1.7 a threat that should be taken seriously.”
The Kent variant, first detected in the UK in September 2020, has been identified as being significantly quicker and easier to spread, and was behind the introduction of new lockdown rules across the UK from January. The variant carries a number of mutations in the spike protein of the coronavirus, including N501Y, D614G, A570D, P681H, H69/V70 deletion, and Y144 deletion. The new study shows that the higher transmissibility of this strain meant that more people who would have previously been considered low-risk were hospitalised with the newer variant.
Leon Danon, senior author of the study from the University of Bristol, was quoted as saying: “We focused our analysis on cases that occurred between November 2020 and January 2021, when both the old variants and the new variant were present in the UK. This meant we were able to maximise the number of ‘matches’ and reduce the impact of other biases. Subsequent analyses have confirmed our results.“
He added: “SARS-CoV-2 appears able to mutate quickly, and there is a real concern that other variants will arise with resistance to rapidly rolled out vaccines. Monitoring for new variants as they arise, measuring their characteristics and acting appropriately needs to be a key part of the public health response in the future.”
Ellen Brooks-Pollock from the University of Bristol was quoted as saying: “It was fortunate the mutation happened in a part of the genome covered by routine testing. Future mutations could arise and spread unchecked”.
According to the World Health Organization, the new variant has been already detected in over 100 countries. The University of Exeter said the new study provides crucial information to governments and health officials to help prevent its spread.
The study, which has been published in the British Medical Journal (March 10), is open access and online at http://www.bmj.com/content/372/bmj.n579.
—Source: University of Exeter