FОТО: PIXABAY.COM.

A hybrid form of mpox has been identified in the UK. Health professionals are not surprised that the sexually transmitted virus has evolved but say it's a reminder of the need for precaution.

Health authorities in the United Kingdomconfirmed on December 8, 2025, that they had detected a so-called "recombinant" version of the mpox virus in a male patient. A virus becomes a recombinant virus when two existing versions of it recombine — by mixing their genetic information — to form a new, hybrid version. This can happen when different types of a virus infect a person at the same time. The UK's national health security agency, UKHSA, said the recombinant mpox virus was detected in a man who had recently returned to the UK from Asia. 

According to the World Health Organization (WHO), Thailand, Malaysia and Japan have recorded mpox cases in 2025 — whereby the case in Japan appeared to have been imported by someone who had returned from travel to an African country. UKHSA's head of sexually transmitted infections, Katy Sinka, and other epidemiological experts said further research would be needed to understand how mpox is changing globally. But mpox and other "poxviruses" are known to mix and create new versions of themselves.

Virus evolution is predictable

Mpox, formerly known as "monkeypox", was originally detected in lab monkeys in Denmark in 1958. The first human infection was found in a Congolese child in 1970. It is related to smallpox and since that disease was eradicated in 1980, circulation of mpox has increased. The two genetically distinct "clades" of mpox are particularly prevalent in West and Central Africa and parts of Asia. The clade IIb subtype is responsible for a global outbreak, ongoing since 2022, which mainly affects Asia, Europe and the Americas.

What is happening on the planet and in each particular city

right now and any future day, you can find out here:

https://ixyt.info/en/USA/West-Hollywood

Paste the desired city into this link!

Viruses continually evolve as mutations occur in their genetic code. This was seen, for example, during the COVID-19 pandemic: New variants of the SARS-CoV-2 virus appeared as it spread around the globe. In this latest case of mpox in the UK, material from Clade Ib and IIb viruses have mixed to create a new hybrid strain. "If this recombinant was formed in human cells, then the person will have been infected with both clades simultaneously," said Jesse Dunning, an infectious diseases consultant at Oxford University’s Pandemic Sciences Institute.

"Exposure to the two different viruses may not have been simultaneous," said Dunning, "but for a [m]pox virus infection in someone with a fully functioning immune system, I think conditions favoring recombination would be optimal if the exposures to the two viruses were simultaneous or close together." Though there is no sign this recombinant mpox virus poses any extra threat, Dunning said it was a timely reminder that mpox continues to evolve, and its infectiousness could change.  "The hope — and it's a reasonable expectation — is that a recombinant virus will not transmit as efficiently as the individual 'component' viruses, but we need laboratory data, case data, and epidemiological data to confirm that," Dunning said.

What is the global situation for mpox infections?

Despite its original association with monkeys, mpox has been detected in various mammals, as well as humans. It was a global outbreak of human infections, involving Clades I and II, which led the WHO to declare a public health emergency in August 2024. It is still a major challenge in the Democratic Republic of the Congo, which reported more than 20,000 cases in the first 10 months of 2025. WHO Director-General Tedros Adhanom Ghebreyesus wound down that order in September 2025, following case reductions in DR Congo, Sierra Leone and Burundi, though mpox still circulates globally.

In humans, mpox is usually transmitted by contact with infected people. That includes skin contact, sexual and mouth-to-mouth contact, and exposure to respiratory particles from breathing. Infected mothers can pass the disease to their babies during pregnancy or birth. Infection can also be transmitted by contaminated objects, like needles and clothing. The primary high-risk group is men who have sex with men (MSM). Following the latest case in the UK, the government there also identified people with multiple sexual partners, those who have group sex, and those who visit sex-on-premises venues (SOPV) as at risk. The UKHSA recommends all such groups to get vaccinated. The current vaccine is 75-80% effective at protecting against Clade II mpox.

Is there a risk of this new mpox strain spreading outside the UK?

It is difficult to say whether this hybrid mpox will spread outside of the UK at the time of writing. But experts suggest it may depend on people's access to a mpox vaccination. While many countries have good access to the mpox vaccine, parts of Asia and Africa have reported difficulties getting vaccines to the people who need them most. If that doesn't improve, it will be possible for mpox to continue evolving and recombining in regions where transmission of the virus is still high. 

And new versions, or mutations, of any virus bring with them the threat of their being more contagious than previous versions. "The key concern now is whether this new strain will alter the virus' transmissibility or virulence," said Boghuma Titanji, an infectious diseases expert at Emory University, US. "The more mpox circulation we permit, the more opportunities the virus has to recombine and adapt, further entrenching mpox virus as a human pathogen that is not going away."

How can I prevent mpox infection?

And while vaccination can help prevent infection, preventative measures are also important.

Experts have emphasized that mpox infection often leads to mild disease and that most people recover in 2-4 weeks. The WHO recommends infected people isolate from others and take steps to prevent further transmission.  These measures include:

• Staying home and in a well-ventilated room, where possible
• Continue thorough sanitary behavior, including handwashing with soap
• Keep lesions dry and uncovered when alone
• Cover lesions and wear a facemask to prevent transmitting the virus when near other people
• Avoid touching lesions that appear during infection and touching other objects that might be touched by others
• Use over-the-counter painkillers as indicated by qualified professionals
• Do not touch or agitate lesions or sores, as this prevents healing and can increase the risk of mpox spreading

Author Matthew Ward Agius

Edited by: Zulfikar Abbany

Permalink - https://p.dw.com/p/551DP