Mpox in 2025: What we know, what we have and what needs to happen next

Mpox has continued to evolve since it made global headlines in 2022. Three years later, the world is seeing two very different realities: one in Africa, where the virus is surging, and another in the rest of the world, where transmission has slowed but risks remain.

Africa: A growing public health crisis

Across Africa, mpox has become a major epidemic. Between January 2024 and May 2025, 26 African countries reported more than 139,000 suspected cases, including 34,824 confirmed infections and roughly 1,788 deaths. Disturbingly, over 21,000 of these confirmed cases occurred in the first few months of 2025 alone. The Democratic Republic of Congo, Sierra Leone and Malawi are now at the epicenter. (1, 2)

What worries researchers most is the rise of a new clade 1a variant carrying APOBEC3 mutations. These mutations may increase the virus’s ability to spread and adapt, raising concerns about whether mpox could become harder to control. Unlike the 2022–2023 outbreak — which was largely driven by clade IIb and linked to sexual networks in non-endemic countries — clade I variants in Africa are spreading more broadly, affecting children, rural communities and health care workers. (3, 4)

Weak health systems, ongoing conflicts and reduced international funding have all hampered early detection and response. Many cases go undiagnosed because diagnostic labs are few and far between. Vaccination efforts remain limited: About 700,000 people have been vaccinated in 11 countries, a fraction of what is needed. (1, 5)

Outside Africa: A fragile calm

In the rest of the world, the picture is calmer but not risk-free. The clade IIb strain that drove the 2022–2023 outbreak continues to circulate at low levels, mostly in specific sexual and social networks. Public health campaigns, targeted vaccination and community engagement have helped bring these numbers down. (3, 4)

However, the virus has not disappeared. Since 2023, small numbers of travel-related clade I cases have been reported in the U.K., Thailand, Germany, India, Sweden, the United States and elsewhere. Thankfully, these imported cases have not yet led to sustained community transmission, but they highlight the ongoing risk of spillover from Africa. For this reason, the World Health Organization continues to monitor mpox closely, recognizing that while it is no longer classified as a public health emergency of international concern, the risk of international spread persists. (1, 5, 16)

Vaccines and treatments: Where we stand

The good news is that we are not defenseless. The main vaccine against mpox is the non-replicating Modified Vaccinia Ankara vaccine, known as JYNNEOS in the United States, Imvanex in Europe and Imvamune in Canada. (6) It has also been authorized in Switzerland, Singapore, Nigeria and the DRC. This vaccine has been a cornerstone of both pre-exposure and post-exposure protection during outbreaks.

Older vaccines, like ACAM2000 — a live, replicating smallpox vaccine — are still available in the U.S. and Canada, but because they can cause more side effects, they are generally used only when safer options are unavailable. Japan continues to use its long-standing LC16 smallpox vaccine. (6)

On the treatment front, tecovirimat, or TPOXX, remains the leading antiviral option. It is authorized for mpox in the EU, U.K., and Canada, and is available in the United States through an expanded-access program. (7,8) However, recent clinical trial data (STOMP and PALM 007) show that tecovirimat does not consistently shorten the course of illness or relieve symptoms in mild-to-moderate cases, particularly when given late in the disease. Its greatest potential benefit appears to be in early treatment of severe disease, immunocompromised patients or those with extensive lesions. Other antivirals — brincidofovir and cidofovir, both originally developed for other viral infections — are occasionally used off-label in severe or complicated cases, sometimes together with vaccinia immune globulin for added immune support. (9, 10) Despite these options, no drug is yet formally licensed specifically for mpox, meaning that clinical care continues to rely heavily on supportive management: pain control, hydration, nutrition and prevention of secondary infections.

The pipeline of new tools is expanding. Moderna is developing an mRNA-based mpox vaccine that has shown strong protection in animal studies, and several biotech companies are exploring new antivirals and combination treatments aimed at improving outcomes and preventing drug resistance. (11, 12)

Preparing for the future

Experts agree that mpox is a wake-up call for how the world deals with emerging infectious diseases. Strengthening surveillance is essential: This means investing in genomic sequencing, improving diagnostic capacity in low-resource settings and connecting data to global early warning systems.

Equitable access to vaccines and medicines must also be a priority, supported by stockpiles, regional manufacturing hubs and streamlined regulatory approval. Research needs to push forward with broad orthopoxvirus vaccines and better therapeutics. (13, 14)

Beyond the laboratory, community engagement is crucial. Stigma-free education campaigns can encourage people to seek testing and care early. A One Health approach, which links human and animal health surveillance, is vital to prevent the virus from spreading to new animal reservoirs. (14,15)

Finally, countries should regularly test their preparedness with simulation exercises and invest in sustainable financing for outbreak response. Mpox is not gone. The window to act is now — before the next orthopoxvirus crisis catches the world off guard.

Image: Colorized transmission electron micrograph of mpox virus particles (blue) cultivated and purified from cell culture. Image captured at the NIAID Integrated Research Facility in Fort Detrick, Maryland. Credit: NIAID

References

1. Mpox epidemic strains African health systems after US aid cuts. Financial Times. Published May 2025.
2. Mpox still a health emergency, says WHO. Reuters. Published February 27, 2025.
3. Suspène R, Raymond KA, Boutin L, et  al.  APOBEC3F Is a Mutational Driver of the Human Monkeypox Virus Identified in the 2022 Outbreak. J Infect Dis. 2023;228(10):1421‑1429. doi:10.1093/infdis/jiad165. Published November 11, 2023. Accessed August 18, 2025.
4. Mpox: The risk of developing an animal base outside Africa remains limited. Le Monde. Published September 7, 2024.
5. World Health Organization. Multi-Country Outbreak of Mpox, External Situation Report No. 53 – 29 May 2025. World Health Organization; 2025. Accessed July 30, 2025. 
6. Food and Drug Administration. Key Facts About Vaccines to Prevent Mpox Disease. Published approximately 10 months ago. Accessed July 30, 2025.
7. Centers for Disease Control and Prevention. Interim Clinical Considerations for Use of Vaccine for Mpox: Vaccination Overview. U.S. Department of Health & Human Services. Updated approximately May 2025. Accessed July 30, 2025.
8. Centers for Disease Control and Prevention. Tecovirimat (TPOXX) for Treatment of Mpox. U.S. Department of Health & Human Services. Updated June 2025. Accessed July 30, 2025.
9. Mullin E. Promising Mpox drug fails in trials as virus spreads. Wired. August 27, 2024. Accessed July 30, 2025.
10. Rigby J. Siga says mpox drug helps sickest, not all patients, needs more data. Reuters. August 15, 2024. Accessed August 18, 2025.
11. GeoVax, Inc. GeoVax accelerates development of GEO-MVA vaccine amid expanding global mpox crisis and reaffirmed WHO emergency designation. Published February 15, 2024. Accessed August 18, 2025.
12. Moderna mRNA mpox vaccine shows early promise in monkey study. ClinicalTrialsArena. September 5, 2024. Accessed August 18, 2025.
13. Centers for Disease Control and Prevention. Mpox in the United States and Around the World: Current Situation. U.S. Department of Health & Human Services. Published July  2025. Accessed July 30, 2025.
14. European Centre for Disease Prevention and Control. Communicable Disease Threats Report, Week 21 (17–23 May 2025). Stockholm: ECDC; 2025. Accessed July 30, 2025.
15. National Academies of Sciences, Engineering, and Medicine. Future State of Smallpox Medical Countermeasures. Consensus Study Report, ed by Lawrence O. Gostin, Lisa Brown, Shalini Singaravelu, and Matthew Masiello. Washington, DC: The National Academies Press; 2024: Chapter  doi:10.17226/27652
16. Cohen J. Africa’s mpox epidemic no longer an international emergency, WHO says. Science. Published September 8, 2025. Accessed September 12, 2025.