A new Covid variant spreading across the US has also been identified in the UK, health chiefs have warned.
The strain, known as BA.3.2, has been detected in nasal swabs taken from four American travellers and clinical samples from five patients in four unidentified states.
It has also been found in three aeroplane wastewater samples and 132 other samples taken in more than 20 states, suggesting its reach is far more widespread than what scientists can currently see.
US scientists have also raised concerns that the vaccines currently available may not protect against this variant.
The strain has also been detected in the UK and is currently being monitored, according to the UK Health Security Agency (UKHSA).
Dr Nick Machin, consultant virologist at the UKHSA, said: “UKHSA is constantly monitoring all available data relating to emergent variants of SARS-CoV-2 through our surveillance programmes. As part of our routine surveillance, we regularly conduct analysis of the severity and detectability of the virus.
“BA.3.2 has been designated as a ‘variant under monitoring’ by the World Health Organisation and has been detected in the UK.”
The variant descended from Omicron and was first detected in South Africa in 2024. The variant started to surge in September 2025 and has since been reported in 23 countries.
The new strain is “genetically distinct” from other JN.1 lineages that have previously circulated in the US, researchers warned in the Center for Disease Control and Prevention’s Morbidity and Mortality Weekly Report.
BA.3.2 carries approximately 70 to 75 genetic changes in its spike protein, a part of a coronavirus that allows it to enter human cells. That means it could be easier for the virus to spread and evade immune protection.
“The 2025–2026 LP.8.1-adapted mRNA Covid-19 vaccine demonstrates protection against currently predominant JN.1 strains but had the lowest antibody neutralisation against BA.3.2 in a laboratory study of seven variants, potentially affecting vaccine-conferred protection,” the researchers said.
Although it is new, there is currently no evidence that this Covid strain causes more severe illness than previous variants of the virus, according to the UKHSA.
“We are currently undertaking an assessment of its impact on diagnostic test performance and will issue further guidance to laboratories as necessary,” Dr Machin added.
“To date, there is no evidence that this variant is more transmissible or causes more severe disease than other recent variants.”
UK scientists do not currently believe the variant is any more of a threat than other strains.
“We can expect constant evolution to facilitate transmission but unless there is a rise in hospital cases there is no reason to suppose any new variant is more ‘dangerous’,” Dr Ian Jones, virologist at Reading University, told The Independent.
He explained the decision to update a vaccine due to mutations will likely be “more a commercial than a scientific decision”.
“If a company feels its vaccine is losing take-up because of a lack of efficacy, they will update it, but until that time, they will not respond to every change that comes along,” he explained.
Dr Jones stressed the population does have immunity against Covid now and the vaccine keeps the disease “in check”, even if it is not protecting against all strains.
He said: “I think we can take some reassurance from the fact that the monitoring systems have picked it up early, but that it is probably ‘just another variant’ that should be noted, but no more for now.”
