The new variant, called NB.1.8.1, or “Nimbus” has reached UK shores and the strain is making up a “growing proportion” of Covid cases worldwide
Doctors have issued a warning over the new highly contagious “Nimubs” strain of Covid, which has seen cases soar in the UK.
The new variant, called NB.1.8.1, or “Nimbus” has reached UK shores and the strain is making up a “growing proportion” of Covid cases worldwide, according to the UK Health Security Agency (UKHSA). China and Hong Kong have seen a surge in cases as well as 21 other countries and 13 cases have already been found in the UK, doctors warn. Symptoms are reported to be broadly the same as earlier versions of the virus with a painful sore throat a possible key sign of the new variant.
According to Dr Naveed Asif, GP at The London General Practice, the NB.1.8.1 variant has a distinctive symptom, a severe sore throat known as a “razor blade sensation”. Other signs of the new strain include common Covid symptoms like fever, muscle aches and congestion as well as redness in the back of the mouth and swollen neck glands.
“However, symptoms can vary widely so vigilance is key,” Dr Asif told the Manchester Evening News. According to the NHS, Covid symptoms include a high temperature, a new continuous cough, a loss or change to sense of smell or taste, shortness of breath and feeling sick.
While early signs of Covid once included symptoms like a severe cough, sore throat and high fever, NB.1.8.1 is felt most acutely in the gastrointestinal tract.
Symptoms of the variant include:
- Nausea
- Vomiting
- Diarrhoea
- Heartburn
- Bloating
- Constipation
- Abdominal pain
The World Health Organization (WHO) added the variant to its official watch list and suggested that it is more transmissible than other strains. However, there isn’t any evidence to indicate that it causes more acute illnesses.
According to WHO, the strain first appeared in January and by late April it was responsible for around 10.7% of global infections, up from just 2.5% a month earlier. The strain has seen a rapid rise in Ireland in recent weeks. According to data from the Health Protection Surveillance Centre (HPSC), the proportion of sequenced Covid samples linked to NB.1.8.1 jumped from 3.7% to 27.3% in the last five weeks, reports Dublin Live.
People in Ireland have been urged to stay home for two days if they display any signs of Covid, with the new variant also causing gastrointestinal problems. The variant, labelled NB.1.8.1, has been flagged in the UK, US and Australia. It has also been linked to spikes in Covid cases in India, Hong Kong, Singapore, and Thailand.
Dr Gayatri Amirthalingam, UKHSA Deputy Director, said: “NB.1.8.1 has been detected in small numbers in the UK to date, but international data suggests that it is growing as a proportion of all COVID-19 cases.
“Based on the available information so far however, there is no evidence to suggest that this variant causes more severe disease than previous variants, or that the vaccines in current use will be less effective against it.”
“Variants like this pop up when the virus mutates, which is normal for viruses, especially ones that spread widely,” explained Dr Chun Tang, GP at Pall Mall Medical. “NB.1.8.1 was first picked up in early 2025 and has since been detected in several countries, including the UK, China and US. It’s got some new mutations that scientists are keeping a close eye on.”