COVID-19: New variant officially named Omicron and Health Secretary Sajid Javid warns of 'huge international concern' as first case found in Europe

A worrying new COVID strain has been classified by the World Health Organisation as a "variant of concern" - its most serious level - and officially given the Greek name Omicron.

The WHO said the variant, first detected in South Africa and previously known as B.1.1.529, "has a large number of mutations, some of which are concerning" and early evidence suggested an increased risk of reinfection compared to other strains.

"This variant has been detected at faster rates than previous surges in infection, suggesting that this variant may have a growth advantage," the organisation added.

It comes as Europe has detected its first case of Omicron - in Belgium - and the UK's health secretary warned there was "huge international concern" over the strain.

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No cases have yet been found in the UK but Sajid Javid said it could be more transmissible than the Delta variant and there is a "possibility it might have a different impact on individuals" who get coronavirus.

Mr Javid said there were worries the variant may make vaccines less effective and could affect one of the UK's COVID treatments, Ronapreve.

He said the UK remained in a "strong position" due to the high vaccination take-up but cautioned the new variant had an "unusually large number of mutations".

The case in Belgium involved an unvaccinated person who had travelled from abroad. They developed symptoms and tested positive on 22 November.

B.1.1.529 has been found in relatively low numbers mainly in South Africa, and has also been detected in Botswana, Hong Kong and Israel.

UK scientists first became aware of the new strain on 23 November after samples were uploaded on to a COVID variant tracking website from South Africa, Hong Kong and then Botswana. A total of 59 samples have been uploaded so far.

Amid the concerns, flights to the UK from South Africa and five other southern African countries - Namibia, Lesotho, Botswana, Eswatini and Zimbabwe - have been suspended until 4am on Sunday.

From Sunday onwards, new arrivals of UK and Irish residents into the UK from those nations will be required to quarantine in government-approved hotels for 10 days after they were placed on the red list on Thursday night.

Non-UK and Ireland residents will not be allowed in from those countries.

And European Union states have agreed to temporarily suspend travel to southern Africa after the detection of the new variant.

European Commission spokesperson Eric Mamer said the restrictions would apply to the same six nations already affected by the UK's move, and also Mozambique.

Later, Washington announced it would restrict travel to the US from the seven countries along with Malawi. The policy does not ban flights or apply to American citizens and lawful permanent residents, an official said.

And Canada is banning the entry of foreign nationals who have travelled through southern Africa.

However, South African health minister Joe Phaahla warned the decision of other countries to impose travel restrictions was "unjustified", but he did admit preliminary studies suggested the variant may be more transmissible.

Mr Phaahla said the "knee-jerk" reaction of many nations "really doesn't make sense", adding that many countries which have taken action are themselves battling new waves.

And he claimed the UK imposed restrictions without consulting South Africa, saying: "It was a unilateral action."

David Nabarro, the WHO's special envoy on COVID-19, suggested that South Africa was being "punished" for detecting the variant and informing the world, and it was "unfortunate" that flights from the country were being stopped.

He told Sky News: "Yes it's good that the world knows about the new variant...but it is totally wrong that there is vilification of the South African scientists who have done the work and it's really unfortunate that the immediate reaction has been to cancel flights and to stop people from South Africa being able to travel."

He added: "Most of the evidence that we have had over the years tells us it is really difficult to keep viruses out of countries through border restrictions. It just does not work."

No cases of the variant have been found in the UK but Salim Abdool Karim, one of South Africa's top epidemiologists, told Sky News he "would expect it to be in the UK".

The new variant was detected in Hong Kong in a passenger from South Africa who was fully vaccinated and officials there notified the South African authorities.

They had come from Gauteng province, home to Johannesburg and Pretoria, where Mr Javid said about 80% of cases checked with a PCR test "have shown something that is known as the S-gene drop out which we associate with this variant".

Mr Javid said South Africa has experienced "exponential growth", with cases increasing fourfold over the past two weeks.

He said it is not yet definitive but does indicate "there could be many more cases of this new variant than just those that have been sequenced".

South Africa saw just over 200 new confirmed cases per day in recent weeks, rising to 2,465 on Thursday. Scientists say the new variant could explain the rise, but that is not certain.

Mr Javid told the Commons the variant has many features of Alpha, Beta and Delta strains but it is not yet known if it causes more severe illness.

Getting a booster jab, when eligible, is even more important now, he added.

Mr Javid confirmed the government is still following Plan A for managing COVID-19 this autumn and winter but warned "if we need to go further, we will".

Meanwhile, England's chief medical officer Professor Chris Whitty has expressed concern about further UK lockdowns if a new variant takes hold.

He said: "My greatest worry at the moment is that people...if we need to do something more muscular at some point, whether it's for the current new variant or at some later stage, can we still take people with us?

"I think my overall view is I think we will. Provided you are clear with people what the logic is, provided they feel that we're being entirely straight with them as to all the data...but I think that's always a worry."