Health

New Covid Variant Nimbus Spreading Fast in the UK and These Symptoms Might Catch You Off Guard

Published on June 12, 2025

A new strain of Covid is making its way across the UK, and it’s not quite behaving like the ones we’ve seen before. The variant, now officially named NB.1.8.1 but commonly referred to as ‘Nimbus’, has health experts on alert due to its unusual symptoms and increasing spread.

So far, 13 cases have been confirmed in the UK, but experts warn that number could rise quickly. The UK Health Security Agency (UKHSA) has flagged that Nimbus is already making up a growing chunk of Covid cases worldwide, with big spikes reported in China, Hong Kong, and another 21 countries.

While symptoms largely mirror earlier versions of the virus, some are catching people off guard. Mohamed Imran Lakhi, Director and Superintendent Pharmacist at Prescription Doctor, told The Mirror that there are six key signs people need to be aware of.

These include a severe sore throat, persistent fatigue, mild cough, fever, muscle aches, and nasal congestion. But some cases are also showing digestive issues like nausea or diarrhoea, which haven’t always been common with previous Covid strains.

“People commonly report a severe sore throat, persistent fatigue, mild cough, fever, muscle aches, and nasal congestion,” Dr Lakhi explained. “Some also experience digestive issues like nausea or diarrhoea, which isn’t always typical with Covid variants.”

Although Nimbus appears to spread more easily, there’s no strong evidence yet that it causes more serious illness than earlier strains. Dr Lakhi says the vaccines, particularly those updated to tackle Omicron, are still holding up well when it comes to preventing serious complications.

“While it seems to spread more easily, there’s no strong evidence so far that it causes more severe illness than previous versions,” he said. “Vaccines, especially those updated for Omicron strains, still offer good protection against serious disease.”

His advice? Stick to the basics. Keep your vaccinations up to date, wash your hands regularly, and consider wearing a mask if you’re in a crowded or enclosed space. And if you start to feel off, especially with a sore throat or extreme tiredness, get tested and try to avoid passing anything on until you know for sure.

“It’s important to stay up to date with your vaccinations and follow basic precautions like hand hygiene and wearing masks in crowded spaces,” Dr Lakhi added. “If you or someone you know develops these symptoms, especially the sore throat and fatigue, it’s wise to get tested and isolate until you know more.”

The World Health Organisation (WHO) has now added Nimbus to its official watch list, although there’s currently no indication it’s more dangerous than previous variants. Still, its rapid spread is being closely monitored.

WHO says the strain first popped up in January and by the end of April, it had already jumped from 2.5% to 10.7% of global cases.

Ireland is also seeing a sharp rise in infections linked to the variant. Figures from the Health Protection Surveillance Centre (HPSC) show the proportion of sequenced Covid samples linked to Nimbus rocketing from 3.7% to 27.3% over the past five weeks.

For now, experts are urging people not to panic but to stay alert and take sensible precautions as this new version of the virus continues to make its way around.

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