The subvariant XBB.1.5 has been identified by the World Health Organisation as being more infectious than previous strains.

The World Health Organisation (WHO) has issued a warning about a new Covid variant which is apparently the "most transmissible yet".

Subvariant XBB.1.5 is spreading rapidly through the United States. Cases have shot up from four percent to 40 percent in December and it's thought to be causing around 70 percent of new infections.

The surge has sparked concerns over how well the UK is prepared to handle a fresh Covid wave due to the ongoing pressure on the NHS and hospitals.

Although this new variant doesn't appear to be any more dangerous than the Omicron strain that swept the UK in 2021, health officials are worried about how easily it's contracted.

"Our concern is how transmissible it is," said Maria Van Kerkhove, the WHO's technical lead on Covid. "The more this virus circulates, the more chances it will have to change."

She said that the subvariant "is the most transmissible form of Omicron to date."

White House Covid-19 response coordinator Dr Ashish Jha also said that the virus was likely more infectious as he posted a couple of updates on Twitter.

He said: "Over the holidays, you may have heard about Omicron XBB.1.5. It went from 4% of sequences to 40% in just a few weeks. That's a stunning increase.

"1. More immune evasive? Probably yes. More than other Omicron variants. 2. More inherently contagious? May be. It binds more tightly to the human ACE receptor. Might affect contagiousness. 3. Is it more dangerous: We don't know."

It comes as health professionals have expressed fears about the UK's inability to deal with another surge in Covid cases if they start to spread rapidly.

University of Warwick virologist Prof Lawrence Young told the Independent: "We didn't have enough public health messaging around the flu jab. We've now got a perfect storm of different respiratory infections going around at the moment and that’s inevitably going to result in more pressure on the NHS.

He continued: "All the information so far shows that whilst this is a very infectious variant and while it can escape the protections from previous vaccination and past infection but there’s no evidence it’s causing more severe disease compared to other Omicron variants but the fact that it’s spreading more and more rapidly, particularly in the US, is very concerning.

At the moment in the UK, XBB.1.5 is thought to be responsible for around one in every 25 Covid infections.

According to the Sanger Institute, one of the UK's largest Covid surveillance centres, 4 percent of Coronavirus cases in the week to December 17 were caused by XBB.1.5.

The subvariant is a mutated version of Omicron XBB, which was detected in Singapore, India and 33 other countries in October.

READ ORIGINAL ARTICLE