More contagious UK variant of Covid spreading rapidly in US: Study

New York: The UK variant of coronavirus, named B.1.1.7, is rapidly spreading across the United States of America by becoming the dominant variant, say researchers.

'The journal Cell' in its findings suggest that future Covid-19 case numbers and mortality rates may be higher in the US than would have been otherwise.

Kristian Andersen, Professor in the Department of Immunology and Microbiology at Scripps Research in the US says "B.1.1.7 rapidly became the dominant SARS-CoV-2 variant in the UK and other countries after its emergence late last year, and the US is now on a similar trajectory."

Researchers have found that the B.1.1.7 variant accommodates several mutations, including the gene that encodes the viral spike protein. These mutations accelerate the spike's capacity to bind to the ACE2 receptor on human cells.

Although there is a lack of evidence to say that the B.1.1.7 variant can evade Covid-19 vaccines, public health officials oversee its high rate of spread and its consequences further.

Standard swab tests for the coronavirus check for distinguishing genetic sequences at three sites on the viral genome. Due to mutations, the B.1.1.7 variant shows up as positive for two of those sites and negative for the third site which is within the spike gene of the virus.

Since the mid-October of last year, S gene target failure became evident frequently at low frequency. SGTF is the result of the Helix test, an analysis that was done across the nation. Roughly 500,000 Helix test results since July 2020 revealed that this two-of-three pattern, known as S-gene target failure.

By the third week of February, it had an elevation in frequency from 0.2 to 10.6 per cent and was detected in patients across 25 different US states and territories.

SARS-CoV-2 variants that have spike gene mutations can also have SGTF pattern. According to the research team, 662 of the 986 samples (67 per cent) contained the B.1.1.7 variant.

B.1.1.7 prevalence could be tested from SGTF pattern on swab tests which can provide a quick and rough indication.