New Covid variant NB.1.8.1 is one of six added to the World Health Organization’s watch-list in the last few weeks, and 13 cases have been in England since January
A new Covid variant that is making up one in 10 Covid-19 infections around the world has been added to the World Health Organization’s (WHO) watch-list in the last two weeks.
The strain, named NB.1.8.1, first appeared on January 21, and by late April 2025 it was counting for around 10.7 percent of all global infections – up from just 2.5 percent four weeks previously, the WHO said.
While all the various Covid-19 strains cause similar symptoms, NB.1.8.1 may be more transmissible than previous variants – though the WHO has stressed that it doesn’t appear to cause worse symptoms or more serious illness.
At least 13 cases have already been confirmed in England, according to UK Health Security Agency (UKHSA) data from PCR-positive Covid samples, with a further seven in Northern Ireland, according to the Public Health Agency. The latest UKHSA data shows Covid-19 activity increased slightly in England between May 26 and June 1. Weekly hospital admissions from the virus slightly increased to 1.49 per 100,000 patients, compared with 1.40 per 100,000 in the previous week.
NB.1.8.1 has already become the dominant strain in China – where the disease originated from – and Hong Kong, with more confirmed cases in the USA, Australia and popular holiday countries like the Maldives, Egypt and Thailand.
Brits who are finding themselves with cold symptoms may actually have Covid – which, according to the NHS, has one tell-tale sign: a new, continuous cough.
By this, it means coughing excessively for more than an hour, or having three or more coughing fits within 24 hours.
You may also experience:
Those with Covid symptoms have been given advice to “stay at home” by top health officials. The UKHSA advises people with a high temperature, or who do not feel well enough to go to work, school, provide childcare or do normal activities, to “avoid contact with vulnerable people and stay at home if possible”.
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.”
NB.1.8.1 was added to a World Health Organization (WHO) watch list on May 23. It is one of six Covid-19 variants currently being monitored by the organisation.
There are currently no Covid-19 restrictions in the UK, the UKHSA said. The WHO has said it is not advising that travel restrictions are imposed in light of the new variant.
“WHO recommends that countries remain vigilant, adapt to evolving epidemiological trends, and leverage Covid-19 management strategies to strengthen systems for all respiratory disease threats,” it said in a report.
“Member States should continue offering Covid-19 vaccines in line with WHO recommendations. Based on the current risk assessment of this event, WHO advises against imposing travel or trade restrictions.”
