New Nimbus COVID Variant Present In The UK, Infections Could Spread This Summer

While memories of masks and enforced lockdowns may be fading for many, COVID-19 frequently rears its ugly head to make an appearance in world headlines. 

British newspapers are now warning that the percentage of known COVID-19 cases attributed to the new Nimbus strain has increased in the UK over the past month , and may rise further this summer.

Figures published by the UK Health Security Agency (UKHSA) show that between 12 May and 25 May 2025, 3.97 percent of tests sequenced in the lab were identified as N.B.1.8.1, while LP.8.1.1 and XFG continued to be the dominant strains (19.87 percent each). However, the data also reveals a steep increase in the percentage of the nimbus strain over the last month.

While the overall number of patients being admitted to intensive care for COVID-19 remains low (0.04 per 100,000 cases), there has been a slight uptick in the number of patients being admitted to hospital with the illness (1.53 per 100,000 cases versus 1.44 per 100,000 cases the week prior).

So, what should you be looking out for? The symptoms are similar to those of previous strains – namely, cough, congestion, headaches, fatigue, sore throat and gastrointestinal symptoms like nausea and diarrhea. Some people may also experience a fever. This particular strain has also been associated with a symptom that has been dubbed “razor blade throat” – an especially severe version of sore throat. 

According to the World Health Organisation (WHO), the virus "is growing rapidly compared to co-circulating variants” and appears to present a mutation that may boost its transmissibility, potentially making it more infectious. 

The N.B.1.8.1 variant was first detected in January 2025. By the end of April, it was the dominant strain in both Hong Kong and China. Since then, it has been reported in numerous other countries, including the US.  The good news is that vaccination continues to provide effective protection.