A highly contagious Covid variant is on the rise in the UK, with official data suggesting infections have doubled in a month. 

The UK Health Security Agency (UKHSA) reported that eight per cent of Covid tests analysed at the start of June were positive for the new ‘Nimbus’ strain. This is up from just four per cent in mid-May.

Nimbus, known scientifically as N.B.1.8.1, is thought to be the most contagious variant of the virus yet with experts warning it could drive a wave of new cases this summer.

Other data collected by the agency shows the total number of tests coming back positive for any type of Covid has increased to 6.8 per cent as of June 15, the latest available data. 

This is up from 5.6 per cent last month and represents the highest figure recorded so far this year. 

Both figures are likely to be an underestimate of how far Nimbus and Covid in general is spreading given how testing has been massively reduced from the height of the pandemic. 

In its weekly report UKHSA also said there had also been a slight increase in hospital admissions for Covid to just over 1.5 admissions per 100,000 people. 

It follows warnings from British scientists earlier this month that Nimbus could lead to a surge in Covid cases.

They warned that many people’s immunity to the virus, built up from previous infections and older jabs, has likely faded meaning they could be at higher risk of falling ill. 

A highly contagious Covid variant is on the rise in the UK, with official data suggesting rates have doubled in a month

Lab studies suggest Nimbus can infect human cells more efficiently than previous strains, and that it may have increased ability to dodge the immune system, making it more likely to infect people.

However, there is currently no evidence that the strain, a descendant of the already super virulent Omicron, is any more likely to cause severe illness or death in those it infects, compared to previous strains.

But any Covid infection with the virus can still be deadly, especially for more vulnerable groups like the elderly or those with compromised immune systems.

Medics have warned that anyone with a ‘razor blade’ throat could have Nimbus.

Dr Michael Gregory, regional medical Director for NHS England in the North West recently said: ‘The variant looks to be spreading rapidly within communities, with top symptoms being a “razor blade” sore throat and swollen neck glands.’ 

Broad Nimbus symptoms are not thought to differ from other Covid variants and include fatigue, fever, muscle ache and a sore throat. 

Experts have also said that current Covid vaccines, which have been reformulated to combat Omicron descendants, are expected to remain effective against Nimbus. 

While data suggests Nimbus is on the rise in the UK it currently still accounts for a minority of total Covid cases. 

Symptoms of Nimbus do not appear to differ from other Covid variants and include fatigue, fever, muscle ache and a sore throat 

Instead, strains LP.8.1.1 and XFG—which, like Nimbus, are descended Omicron—were the most common Covid variants accounting for a fifth and a quarter of all tests analysed, respectively. 

Earlier this month the World Health Organisation said Nimbus now accounts for 10.7 per cent of Covid infections worldwide, compared to just 2.5 per cent in May.

Other UKHSA data, shows that only 59 per cent of Britons in England aged over 75 had taken up the offer of a Covid vaccine.

Uptake fell to just one in four among under 75s with compromised immune systems, who are also eligible for the jab on the NHS.

NHS England’s spring Covid vaccine drive is drawing to a close with the system closing for bookings earlier this week. 

Vaccine companies are reported to be in the midst of updating their shots to fit the ‘Nimbus’ strain. 

Moderna said late last month that its updated mNEXSPIKE shot will be available by the fall. 

Nimbus first originated from China, where it has been linked to a rise in cases and A&E visits. 

The variant has taken off in the US where data suggests it now makes up over a third of Covid cases, making it the second-most common variant. 

Nimbus’ as a name was coined by Canadian evolutionary biologist T Ryan Gregory, the mind behind many popular variant names.