Concerns around growing around a new variant of Covid emerging in southern Africa, which has seen six new countries added to the red travel list.

Currently identified as B.1.1.529, the variant has seen flights between England and South Africa, Namibia, Lesotho, Botswana, Eswatini and Zimbabwe suspended and all six added to the red list of travel.

Heath secretary Sajid Javid, who addressed Commons about the matter on Friday, has said the new variant "may be more transmissible" than the Delta strain of the virus. He added that more nations may be added to the red list if necessary.

He said: "We are keeping this under review and there are very live discussions going on about whether we should and when we might add further countries, and we won't hesitate to act if we need to do so."

Mr Javid said experience has shown "we must move quickly and at the earliest possible moment", adding there were concerns the variant may be more transmissible, make vaccines less effective and may affect one of the UK's Covid treatments, Ronapreve.

Paul Hunter, a viral expert at the University of East Anglia, said it has the potential to become a "big problem".

He said: "We do not know a lot about it at this stage and will have to be watching very closely what happens in southern Africa.

"We will not know more until we have more data about the spread in South Africa. If by the end of the week there are around 200 or so cases in Africa [currently there are 59] we could have a big problem on our hands."

The new variant is causing global concern, but speaking to the BBC Prof James Naismith, director of the Rosalind Franklin Institute at Oxford University, said: "It's bad news, but it's not doomsday."

The variant would "almost certainly" make vaccines less effective, but they would still work to some extent. New drugs to treat Covid-19 would not be affected by the variant, he suggested.

Prof Hunter added the situation was "worrying" because the variant has more mutations of spike proteins, which viruses use to get into human cells. This could mean vaccines are less effective against it.

But he added: "This does not necessarily mean it is going to be a problem, but it does raise concern.

"At the moment it is not obvious if it is more infectious than any other variant, or if it is more resistant to immunity, whether that is from vaccines or natural immunity from having caught it."

Prof Hunter added that he was unsure whether travel restrictions would prevent the variant spreading or simply delay the spread - but added if it does spiral the way vaccines have been rolled out would be partly to blame.

He said: "I believe the world would have been far better working through the most vulnerable people globally, rather than wealthier countries working through their populations.

"If vaccines had been rolled out in order of vulnerability on a global basis then this may not have happened."

Scientists say variants are more likely to arise in unvaccinated populations.

Norfolk’s director of public health, Dr Louise Smith, said: "We have reviewed the data from Norfolk in detail and at present have no direct or indirect evidence of any B.1.1.529 variant being in the county.

"We will continue to monitor the data on a daily basis, and to work closely with our colleagues in the UKHSA to identify and respond to cases of novel Covid-19 variants of concern in line with national and international guidance."

“Vaccination remains the best line of defence against Covid-19, including for new variants.

"We encourage anybody who hasn't yet had their first or second dose to do so, and for those eligible for their booster dose to take this up as soon as possible.

"We also encourage everybody to test regularly, and to isolate if they have a positive test or symptoms of Covid-19.

"For the B.1.1.529 variant and in general, we will continue to update and develop our local response according to the latest national guidance and best available scientific evidence.”