Video report by ITV News Health Editor Emily Morgan
A coronavirus "mutation of concern" has been identified in England, prompting the government to work with vaccine firms to assess the effectiveness of Covid-19 vaccines on new strains of the virus.
Scientists have described the discovery of the mutation, which has been shown to reduce the effectiveness of vaccines in preventing people contracting Covid-19, as a "worrying development”.
The mutation - known as E484K, which is found on the South African and Brazilian variants - has now been identified on some samples of the UK variant of Covid-19 which was first found in Kent.
A door-to-door testing blitz is underway in eight postcode areas in England, after 105 cases of the South African variant were found, to contain the strain and ensure it does not interfere with the vaccine rollout.
Public health experts still believe current vaccines will still be effective against these strains and are good at preventing severe disease.
But laboratory studies have shown that antibodies – which are produced by the body to counteract infection – 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 UK variant, also known as B.1.1.7.
But a recent report published by Public Health England said gene sequencing has shown that the E484K mutation has occurred spontaneously in a handful of cases of the UK variant.
The report shows that sequencing has uncovered 11 Kent cases with the spontaneous E484K mutation from 214,159 samples tested.
Speaking in the Commons, Health Secretary Matt Hancock said the government is working closely with pharmaceutical firms in case vaccines need to be tweaked to accommodate new variants.
He said: “We’re working with pharmaceutical companies and with the scientists to understand both whether the such modifications are needed, where they are needed, and how they can be brought to use on the frontline as quickly and safely as possible.
Here's everything we know so far about the South African variant in the UK:
“This is obviously a very important consideration given the new variants that we’ve seen.
“And we have confidence that modifications to vaccines, should they be necessary in large scale, will be available more quickly than the original vaccines.
“And just as we did first time round, when we got in there early and we bought at risk, so we are having exactly the same conversations right now with the pharmaceutical companies to make sure that we are right at the front of this one.”
Mr Hancock told MPs that the aim of community testing for the South African variant – currently targeting around 80,000 people in eight postcode areas – is to “stop its spread altogether”.
He said: “As with the variant first identified here in the UK, there is currently no evidence to suggest it is any more severe but we have to come down on it hard.
“Our mission must be to stop its spread altogether and break those chains of transmission.”
The Cabinet minister also suggested more areas – Bristol and Liverpool – have been added to the list for community testing since the eight postcodes were announced on Monday.
“In those areas where this variant has been found – parts of Broxbourne, London, Maidstone and Southport, Walsall and Woking – we’re putting in extra testing and sequencing every positive test,” he said.
“We have also seen 11 cases of mutations of concern in Bristol and 32 in Liverpool, and are taking the same approach. In all these areas it is imperative that people must stay at home and only leave home where it is absolutely essential.”
The government has imposed travel bans on foreign nationals arriving to the UK from South American and southern African countries over the variants, and will soon force UK residents returning from there to quarantine in hotels for up to 10 days before being allowed into the community.
Former chief scientific reporter to the government, Sir Mark Walport, has told ITV News that "in a perfect world" the government would "do everything we possibly can" to stop viral variants coming into the country.
But he suggested a complete border closure would be tough for the UK.
"The reality of course is that the UK depends on international trade, it depends for our resilience on imports of all sorts of things and so closing borders completely is a very, very difficult thing to do."
He added: "It's important that while we do the best we possibly can, inevitably there will be some permeability at the border, and we know also that these mutations will arise independently anyway."
Dr Julian Tang, honorary associate professor at the University of Leicester, described the finding as “a worrying development, though not entirely unexpected”.
In full: Health Secretary Matt Hancock delivers a Covid update to MPs
He said it is important that people follow lockdown rules to prevent opportunities for the virus to mutate further, suggesting that allowing spread could provide a “melting pot” for different emerging variants.
“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,” he added.
Clinical trials for two coronavirus vaccines – Novavax and Johnson & Johnson – have shown the jabs offer some protection against variants with the E484K mutation.
However, they are less effective than against the variant that has been around since the start of the pandemic.
Laboratory studies also suggest vaccines developed by Moderna and Pfizer/BioNtech could work against variants, while variant checks against the Oxford University/AstraZeneca vaccine are ongoing.