UK variant of COVID-19 has significantly higher death rate, study finds

A highly infectious variant of COVID-19 that has spread around the world since its discovery in Britain late last year is between 30% and 100% more deadly than previous dominant variants, said Wednesday researchers.

In a study comparing death rates among people infected with the new variant of SARS-CoV-2 known as B.1.1.7 to those infected with other variants of the COVID-19 virus, scientists said the mortality rate of the new variant was “significantly higher”.

The B.1.1.7 variant was first detected in Britain in September 2020 and has since been found in over 100 other countries as well.

It has 23 mutations in its genetic code – a relatively large number – and some of them have made it much easier to propagate. Scientists say it’s about 40 to 70 percent more transmissible than previous dominant variants that were circulating.

In the British study, published Wednesday in The BMJ, infection with the new variant resulted in 227 deaths in a sample of 54,906 COVID-19 patients, up from 141 among the same number of patients who were matched for age, the gender, socio-demographic context. , date of infection and other factors, but infected with other variants.

The risk ratio for mortality with the B.1.1.7 variant was 1.64, compared to previously circulating versions of the virus.

“Coupled with its ability to spread rapidly, this makes B.1.1.7 a threat that must be taken seriously,” said Robert Challen, a researcher at the University of Exeter who co-led the research.

Independent experts said the results of this study add to previous preliminary evidence linking infection to the B.1.1.7 virus variant with an increased risk of dying from COVID-19.

The first results of the study were presented to the UK government earlier this year, along with other research, by experts on its Advisory Group on New and Emerging Respiratory Virus Threats, or NERVTAG.

Lawrence Young, virologist and professor of molecular oncology at the University of Warwick, said the precise mechanisms behind the higher fatality rate from variant B.1.1.7 were still unclear, but “could be related at higher levels of virus replication as well as increased transmissibility ”.

He warned that the UK variant was likely fueling a recent outbreak of infections across Europe.

SOURCE: The BMJ, online March 10, 2021.

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