The state of global mpox in 2024: new variants, rising outbreaks in Africa, and vaccine trials just starting

A picture of the patient’s lesions came through on WhatsApp. Doctors in Kamituga, a mining town in the Democratic Republic of the Congo (DRC), thought that they might be dealing with a case of smallpox—but Leandre Murhula Masirika knew better.

“I saw the picture and said, ‘This is mpox,’” recalls Murhula, who is an mpox specialist at the Natural Sciences Research Centre in Bukavu. He made some phone calls and headed to Kamituga, where his suspicions were confirmed.

That was last autumn. Since then, genomics studies by Murhula and colleagues indicate that the doctors in Kamituga have been dealing with a new strain of the “monkeypox” virus that causes mpox: a strain known as clade Ib.1 This is distinct from the clade IIb version of the virus that drove a huge global outbreak of mpox in 2022. At the hospital in Kamituga, 20 cases are now arriving every week.

So alarming is the situation that the World Health Organization has called for urgent action to tackle this and other ongoing mpox outbreaks.2 The DRC alone has had around 8600 mpox cases, leading to 410 deaths. The neighbouring Republic of the Congo declared an mpox epidemic in April after 19 cases were detected there.3

The monkeypox virus, which is related to the smallpox virus, was discovered in the late 1950s and has been known to infect humans since 1970, when it was observed in six children in the DRC. Since then, any cases have largely been reported on the African continent. Then came 2022 and a sudden spread of infections in Europe, the US, and elsewhere—leading WHO to declare a public health emergency of international concern, at a time when …