A new strain of mpox – the virus formerly known as monkeypox – has been detected in England, health officials have confirmed. An individual has tested positive after recently travelling to Asia, the UK Health Security Agency (UKHSA) has said.
Early tests show that this strain contains two different mpox lineages — a phenomenon that scientists say can occur as viruses evolve. UKHSA stresses it is continuing to monitor the situation.
Small numbers of cases linked to a different strain (clade Ib) have been reported in the US and several European countries.
While mpox is usually mild, it can be more serious for some people. Officials are therefore urging eligible groups to get vaccinated, as studies show the jab offers effective protection against severe illness.
Here’s what we know so far.
What is mpox and what are the symptoms?
Mpox is a viral infection that spreads through close skin-to-skin contact, bodily fluids or contaminated items.
Mpox is usually mild, but for some people — particularly those who are not vaccinated — the illness can be more severe.
Typical symptoms include:
A skin rash or pus-filled lesions lasting 2–4 weeks
The incubation period — the time between exposure and the onset of symptoms — is typically five to 21 days.
Anyone who thinks they may have mpox should contact NHS 111 for advice.
A patient infected with mpox in Kamituga, South Kivu province, in the east of the Democratic Republic of Congo in 2024. (Getty Images)
How do you catch mpox?
Mpox doesn’t spread easily between people, but it can pass on through close contact with someone who is infected.
According to the NHS, it can spread through:
Direct contact with the rash, lesions or scabs — including during sexual contact, kissing, cuddling or any skin-to-skin contact
Bodily fluids, such as saliva, nasal mucus or semen/vaginal fluids
Contact with contaminated items, including clothing, bedding, towels or surfaces used by someone with mpox
In parts of central and east Africa, mpox can also be caught from infected animals.
Why are health officials talking about mpox now?
A new mpox strain has been detected in England, described by officials as a recombinant virus — meaning it contains genetic material from more than one mpox lineage.
Tests revealed elements of strains called clade Ib and clade IIb, both of which are currently circulating, according to the UKHSA.
The UKHSA emphasises that a virus of this kind evolving is not unusual, but says continued tracking remains important, given how mpox is spreading and shifting.
According to Dr Katy Sinka, head of sexually transmitted infections at UKHSA,
“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.”
Is this strain circulating in the UK?
As detailed in the UKHSA’s latest update, the recombinant strain has been identified in one individual who has recently travelled to Asia.
However, back in October, clade Ib mpox showed signs of community transmission, with locally acquired cases identified in the USA, Spain, Italy, the Netherlands and Portugal — none of which were linked to travel in previously affected countries.
Health officials say vaccination remains the most effective way to prevent severe mpox in eligible groups. (Getty Images)
Is there an mpox vaccine?
The UK has a routine vaccination programme targeting groups at higher risk of exposure.
Those eligible include people who:
have multiple sexual partners
visit sex-on-premises venues
Studies show the vaccine is 75–80% effective against the virus.
A large proportion of eligible people in the UK have already received the vaccine, though Dr Sinka urges eligible groups who haven’t to get the jab:
“Getting vaccinated is a proven effective way to protect yourself against severe disease, so please make sure to get the jab if you are eligible.”
You can arrange a vaccination through a sexual health clinic.
UKHSA has said they have shared details of the new strain with international partners, including the World Health Organization, to support ongoing global monitoring.
For now, officials emphasise staying informed, getting vaccinated if eligible, and seeking medical advice if you develop symptoms.
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