South Africa is being placed on a new travel red list from noon on Friday amid widespread concern over a new Covid-19 variant that has been detected in the country.
Neighbouring Botswana, Namibia, Zimbabwe, Eswatini (formerly Swaziland) and Lesotho will also be red-listed with flights temporarily banned.
The move marks a return to travel restrictions with anyone returning from the newly red-listed nations forced to spend 10 days in hotel quarantine on their return to the UK, with a £10,000 penalty for those flouting the rules.
The red list was scrapped earlier this month when all countries were taken off the list.
People who have recently arrived from South Africa will shortly be offered a free test in an attempt to detect any imported cases.
There are currently between 500 and 700 people a day coming into the UK from South Africa.
Variant 'may be more transmissible than delta strain'
Sajid Javid, the Health Secretary, said the new variant "may be more transmissible" than the delta strain and added "the vaccines that we currently have may be less effective".
Asked what the new variant meant for Britain in the run up to Christmas, Mr Javid said: "We've got plans in place, as people know, for the spread of this infection here in the UK and we have contingency plans – the so-called Plan B.”
No cases of the variant have been detected so far in the UK. Officials believe there is a low likelihood of the new strain entering Britain as the prevalence of infection — less than one per cent a week ago — in South Africa is relatively low.
Health officials believe the new variant, called B.1.1.529, is the worst yet to emerge. Its catalogue of 32 mutations have made the virus “dramatically different” to anything seen before, according to experts.
The mutations occur throughout the virus, including on the spike protein which allows the coronavirus to enter human cells, leaving leading molecular biologists and virologists in the UK concerned.
Experts fear the variant has the potential to be more infectious than delta, the current dominant strain, and better at dodging antibodies than the beta variant. Beta first emerged in late 2020 in South Africa and is the strain most capable of evading the vaccine.
The World Health Organisation is meeting with South African officials on Friday to discuss the rapidly evolving situation in the country.
Health officials will decide whether to declare the new strain a “variant under investigation” or a “variant of concern”. The UK currently has no plans to make this distinction itself due to a lack of data.
The strain, once officially recognised by the WHO, is likely to receive the moniker Nu, the 13th letter of the Greek alphabet.
B.1.1.529 has been found in 77 cases in South Africa, four in Botswana, and one in Hong Kong, in a patient who had recently visited South Africa.
The new variant can be picked up by standard PCR tests as it avoids one of the three markers used to identify the virus, called an S gene drop-out. Therefore, a person infected with the new variant has just two of these three markers, and this would make it easy for Britain’s world-leading surveillance system to identify any imported cases.
All the molecular indicators point to the new variant being more transmissible and able to evade vaccines.
It will take at least a week before British experts at the UK Health Security Agency will be able to get hold of samples of the new variant in order to run their own experiments at Porton Down.
Dr Emma Hodcroft, a molecular epidemiologist at the University of Bern, said: "We cannot perfectly predict virus behaviour from mutations.
"Even lab work doesn't perfectly mirror what happens in complex, whole-body real-life. Other, alarming variants have failed to spread very far in the past. We need more data."
Professor Danny Altmann, an immunologist at Imperial College, London, told The Telegraph: “We have all become pandemic fatigued, yet if this was a report of a terrorist threat, we would now be raising the threat level from amber to red.”