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New mpox strain identified in England, says UKHSA

New mpox strain identified in England, says UKHSA
Liudmila Chernetska via GettyImages
By Jerome Smail
9 December 2025



The UK Health Security Agency (UKHSA) has said a new recombinant mpox strain has been identified in England.

The strain was identified in an individual who recently travelled to Asia and the agency is assessing the significance of the strain, with the genomic sequencing showing the virus contains elements of both clade Ib and clade IIb mpox.

The UKHSA said this development was not unexpected, given that both clades are currently circulating, but it added that this latest development highlighted the continued need for genomic surveillance.

The UK has a routine mpox vaccination programme for eligible groups, including people with multiple sexual partners, those who participate in group sex and individuals who visit sex-on-premises venues.

Studies show the vaccine offers around 75% to 80% protection.

Dr Katy Sinka, head of sexually transmitted infections at the UKHSA, said: ‘Our genomic testing has enabled us to detect this new mpox strain. It’s normal for viruses to evolve, and further analysis will help us understand more about how mpox is changing.

‘Although mpox infection is mild for many, it can be severe. Getting vaccinated is a proven effective way to protect yourself against severe disease.’

The UKHSA has shared the genomic findings with international partners, including the World Health Organisation, to support global monitoring.

A version of this story was first published on our sister title The Pharmacist.

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