The World Health Organisation (WHO) has confirmed a new strain of Covid-19 that has spread across the US and cases have now been found in the UK.

Covid-19 infections in the UK have jumped to their highest level since the summer, with nearly three million people likely to have had the virus at Christmas.

The figures come as the country is experiencing its worst flu season for a decade and ambulance handover delays at hospitals are at a record high.

A total of 2.97 million people in private households in the UK were likely to test positive for coronavirus in the week to December 28, according to the Office for National Statistics (ONS).

Around one in 20 people in England are likely to have had Covid-19 over the festive period, along with one in 18 in Wales and one in 16 in Northern Ireland.

The current wave of coronavirus could prove to be one of the biggest the UK has seen.

Infections peaked at 4.3 million last winter during the spread of the Omicron variant of Covid-19, but this was topped a few months later during the wave caused by the Omicron BA.2/3 subvariants, when infections reached a record 4.9 million.

Here is what we know so far about the 'Kraken' variant:

What's the difference between this variant and other variants?

According to the COVID technical lead for the WHO, Maria Van Kerkhove, officials are worried about how quickly XBB.1.5 is spreading, "It is the most transmissible subvariant that has been detected yet," she said in a press conference.

What are cases looking like in the UK?

The latest wave has not been linked with a specific new variant, but is instead likely to reflect an increased amount of social mixing and airborne transmission, particularly during the cold weather when more people are likely to be indoors.

A new subvariant of Omicron, named XBB.1.5, has become dominant in parts of the US but is responsible for fewer than 5% of infections in the UK, experts said.

What have health bosses said in the UK?

Jonathan Ball, professor of molecular virology at Nottingham University, said there is “no evidence” that XBB.1.5 is more dangerous than other variants, adding: “It might be able to escape antibodies, but that’s not the only immunity we have. Our immune system is used to adapting to viruses.

“We’d better get used to the emergence of new variants, at least for the foreseeable future.

“Yes, they will lead to new waves of infection, but vaccination is still proving to be a very effective weapon to protect the most vulnerable from serious disease.”

What are hospitals looking like at the minute when it comes to Covid-19?

The number of people in hospital who have tested positive for Covid-19 has been on an upward trend since the start of December, though there are signs the figures may have levelled off in recent days.

Some 9,332 patients in England were recorded as having Covid-19 on January 4, down 1% on the previous week.

Hospital numbers in England reached 17,000 during the wave of infections last winter.

The rise in Covid-19 patients is one of a number of challenges facing the NHS.

An average of 5,105 flu patients were in general hospital beds in England last week, up 47% on the previous week and nearly seven times the number at the start of December, NHS data shows.

Hospital admissions for flu were running at their highest level in at least a decade just before Christmas, though the rate fell in the run-up to New Year.

What are the symptoms of the variant?

  • Sore throat
  • Blocked nose
  • Runny nose
  • Sneezing
  • Cough no phlegm
  • Headache
  • Cough with phlegm
  • Hoarse voice
  • Muscle pains aches
  • Altered smell

Why is is called the Kraken variant?

Some, especially in the Twitterverse, have taken to calling XBB.1.5 the "Kraken" subvariant. The name comes from biology professor T. Ryan Gregory of the University of Guelph in Canada.

Gregory wanted to give this subvariant a name with more oomph than XBB.1.5 or even Omicron to better communicate info to the public and chose the name of a sea monster from Norse mythology.

Can I catch COVID again after having it once?

In short form, yes. While antibodies will have built up, people can get Covid-19 multiple times.