London: The highly infectious variant of the novel coronavirus which swept across the UK last year before spreading worldwide, could be 30 to 100 per cent deadlier than previous versions of the virus, according to a new study.
The research, published in the British Medical Journal on Wednesday, noted that this variant, B.1.1.7, is linked to a significantly higher mortality rate amongst adults diagnosed in the community compared to previously circulating strains.
In the study, epidemiologists from the Universities of Exeter and Bristol in the UK, compared death rates among people infected with the new variant and those infected with other strains.
They found that the new variant led to 227 deaths in a sample of 54,906 patients compared to 141 amongst the same number of closely matched patients who had the previous strains.
"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," said Robert Challen, lead author of the study from the University of Exeter.
Since this variant was first detected in the UK in September 2020, it has been proven to be significantly quicker and easier to spread, with more people, who would have previously been considered low risk, hospitalised because of it.
Assessing data from over 54,609 matched pairs of patients of all age-groups and demographics, and differing only in strain detected, the researchers found that there were 227 deaths attributed to the new strain, compared to 141 attributable to earlier strains.
"We focussed 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," said Leon Danon, senior author of the study from the University of Bristol.
"This meant we were able to maximise the number of "matches" and reduce the impact of other biases. Subsequent analyses have confirmed our results," Danon explained.
Due to the ability of the coronavirus to mutate, he believes there is a real concern that new variants may 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," Danon added.