The UK variant, termed B117 of Covid-19, is 45 per cent more contagious than the original virus, according to a new study that took data from about 300,000 PCR tests.
The study, led by researchers from the Tel Aviv University in Israel, used a kit that tests for three different viral genes. In the British variant, one of these genes — the S gene — was erased by the mutation.
“Consequently, we were able to track the spread of the variant even without genetic sequencing,” said Ariel Munitz from the varsity`s Department of Clinical Microbiology and Immunology.
Data from about 300,000 PCR tests showed that the spread of the UK variant was very rapid: On December 24, 2020 only 5 per cent of the positive results were attributed to the British variant. Just six weeks later, in January 2021, this variant was responsible for 90 per cent of Covid-19 cases in Israel. The current figure is about 99.5 per cent.
The findings were published in the scientific journal Cell Reports Medicine.
“To explain this dramatic increase, we compared the R number of the SARS-CoV-2 virus with the R of the British variant. In other words, we posed the question: How many people, on the average, contract the disease from every person who has either variant? We found that the British variant is 45 per cent — almost 1.5 times — more contagious,” Munitz said.
Moreover, the new study proves that active monitoring of at-risk populations works. “There is a threshold value for determining whether a specific test is positive or negative for the virus — with a lower value indicating a higher viral load,” Munitz added.
A recent study published in The Lancet Infectious Diseases, reported that although the UK variant remains more contagious than original strains of the virus, it did not increase the severity of illness and people were not more likely to die with it.