The global outbreak of mpox in 2022-23 reached over 100 countries and sparked a wave of scientific research and public health interventions. That outbreak was caused by mpox clade IIb, a strain that spreads through close physical contact and was found for the first time in both sperm and vaginal fluid, confirming its potential as a sexually transmissible infection.
During that time, the global health community responded with urgency. Though the overall death rate was low around 0.1% it was much higher, approximately 15%, among people with severely compromised immune systems, such as those with advanced HIV. Effective public health messaging, targeted outreach to at-risk communities, and vaccine distribution helped contain the outbreak. In particular, sexually active men who have sex with men were engaged as partners in the response, and access to vaccines played a major role in controlling the spread.
Viruses mutate more as they spread. Clade II did just that, eventually giving rise to the clade IIb strain responsible for the global spread. A similar development is now occurring with the more severe clade I mpox, which caused over 14,000 cases and 654 deaths in 2023. This clade has hit central Africa especially hard, with the Democratic Republic of the Congo (DRC) facing a dramatic surge in cases, mainly among children under 15 and their caregivers.
Clade I mpox is more lethal than clade II, especially for children under five. Its mortality rate ranges between 3% and 10%, largely due to disparities in access to healthcare, including antibiotics, hospital beds, and intensive care. Yet, despite the growing number of cases, clade I mpox has received little international attention compared to the 2022 outbreak that affected wealthier nations.
In countries like the DRC, where mpox has been spreading through close contact, respiratory droplets, contaminated materials, and even animals, there is a severe shortage of resources. The vaccine used successfully in the US and Europe known as Jynneos or Imvanex has not been made available in Africa. Priced at around $100 per dose, it is financially out of reach for most low- and middle-income countries. Dependence on limited vaccine donations and insufficient investment in laboratory capacity has left the region underprepared.
In 2024, the virus spread rapidly from eastern DRC, reaching over 16,000 new cases and causing more than 500 deaths. Its movement across porous borders and within camps for displaced people spurred new genetic studies. These revealed enough viral mutations to classify it as a new sub-variant: clade Ib. This sub-variant has since reached several other African nations and even appeared in Europe for the first time, in a traveler returning to Sweden.
Despite the low risk to general populations in wealthy countries, international travelers to affected regions may contract the virus and unknowingly spread it at home. Still, a global outbreak is not inevitable. With proper measures community engagement, contact tracing, genomic surveillance, and vaccination the spread of clade Ib can be controlled.
For these tools to be effective in Africa, three things are essential: free access to diagnostic testing, labs capable of identifying mpox clades, and equal access to vaccines. Millions of doses will be required to protect those most at risk. A declaration of a public health emergency of international concern by the World Health Organization could facilitate this by coordinating international efforts, expediting vaccine licensing, and enabling mass production and distribution where it’s needed most.
This outbreak can be stopped. The question is whether the global community will act before it’s too late.
