A coronavirus variant with a “double mutation” first identified in India was found in the UK.
Public Health England figures showed 77 cases of the variant were recorded up to April 14. Seventy-three cases were recorded in England and four in Scotland.
It is the first time officials have acknowledged the presence of the strain, known as B.1.167, in Britain.
The strain was classed as a “variant under investigation” but this could progress to “variant of concern” if evidence shows it is more infectious, more deadly or more resistant to vaccines than previous mutations.
The variant was first detected in India, which is battling a huge surge in case numbers.
India reported 217,353 positive test results on Friday – the eighth daily record in a row.
Some experts are concerned that the new strain could be effective at evading human immune response. The variant contains two mutations to its spike protein that could also make it easier to spread.
There are three variants of concern in the UK – those first detected in south-east England, South Africa and Brazil.
Prof Paul Hunter from the University of East Anglia said the arrival of the Indian variant was worrying.
"These two escape mutations working together could be a lot more problematic than the South African and Brazilian variants, which have only one escape mutation," he told The Guardian.
“It might be even less controlled by vaccines than the Brazilian and South African variants.”
Prime Minister Boris Johnson on Thursday announced his upcoming trip to India would be scaled down because of the worsening pandemic situation in the country.
He was expected to spend four days in the country but Downing Street said the bulk of the work could be done in one day.
Britain has not classed India as a red-list destination, which requires travellers arriving from that country to enter hotel quarantine.
Authorities this week ramped up efforts to stop the spread of a cluster of the South African variant across London.
The largest surge-testing operation in the UK to date is in place to test more than one million residents for Covid-19.
Six hundred cases – rising by 56 in a week – of the South African strain were identified in the UK.
