A "mutation of concern" has been detected in the variant of coronavirus first identified in the UK, which scientists have described as "a worrying development".
Britain has detected 43 cases of the coronavirus featuring these mutations in Bristol and Liverpool, British health minister Matt Hancock said today, adding that new variants meant the government had to act with caution.
"We've also seen 11 cases of mutations of concern in Bristol, and 32 in Liverpool," Mr Hancock told MPs, saying they were additional to the 11 cases of the variant first identified in South Africa that were not linked to international travel.
"We must continue to act with caution, not least because of the renewed challenges posed by new variants of the coronavirus," he said.
The mutation linked to the variant identified in the UK, known as E484K, is already present in both the variants that originated in South Africa and Brazil, and experts believe it could have an impact on the effectiveness of some Covid-19 vaccines.
Laboratory studies have shown that antibodies are less able to bind to a part of the virus known as the spike protein, in order to stop it from unlocking human cells to gain entry.
It was previously thought this mutation was not present in the variant from the UK.
But a recent report published by Public Health England said gene sequencing has shown that the E484K mutation has occurred spontaneously in only a handful of cases of the UK variant.
Dr Jonathan Stoye, group leader, Retrovirus-Host Interactions Laboratory at The Francis Crick Institute, said: "This suggests that the UK variant is now independently acquiring the E484K change.
"From a virological standpoint, appearance of new variants by mutation during replication cannot be considered surprising.
"Whether this change will provide significant growth advantages for the novel virus causing it to predominate remains to be seen."
Dr Julian Tang, honorary associate professor at the University of Leicester, described the finding as "a worrying development, though not entirely unexpected".
He said it is important that people follow lockdown rules and get new cases of coronavirus down to prevent opportunities for the virus to mutate further.
Prof Tang said that allowing spread could provide a "melting pot" for different emerging variants.
He said: "We really need to reduce our contact rates to reduce the opportunities for viral spread (and) replication to reduce the speed with which these different virus variants can evolve."
