Mpox
CEPI is supporting efforts to accelerate new mpox vaccines and expand access to existing vaccines to help tackle the ongoing deadly mpox outbreaks in the Democratic Republic of Congo and other countries. Findings could also support the development of vaccines against other Poxviruses.
What is mpox virus?
Mpox, previously known as monkeypox, is a contagious infectious disease caused by the mpox virus, which is a member of the Poxvirus family. Other Poxviruses include variola virus which caused the highly fatal but now eradicated smallpox disease.
Mpox mainly spreads from person to person through close physical contact. This includes, but isn’t limited to, sexual contact. The virus is also found in small mammals in central, east and west Africa and can also spread from animals to humans.
There are two different known forms, or clades, of the mpox virus known as Clade I and Clade II. In severe cases it can be deadly, with the Clade I virus usually causing a higher percentage of infected people to get severely sick or die compared to Clade II.
In 2024, a new Clade, known as Clade 1b was identified in the Democratic Republic of Congo (DRC), which may be contributing to the escalating number of cases in the region.
Where does mpox occur?
The first recorded human case of mpox was in the DRC in 1970.
Since 2005, the DRC has reported thousands of cases every year. In 2017, there was an outbreak of mpox in Nigeria and the virus also spread to other nations.
A multi-country outbreak of mpox Clade II led to the declaration of an international health emergency in 2022. It spread rapidly via sexual contact and in many countries where the virus had not been seen before. The emergency was declared to be over in May 2023 following a sustained global decline in cases.
The DRC is currently the epicentre for the worst-ever mpox outbreak, declared both a continental and global health emergency by Africa CDC and WHO. Over a dozen countries in Africa have reported Clade 1b cases, as well as Sweden, France, India, Thailand and the UK.
Over 120 countries have reported mpox between January 2022 to August 2024 with over 100,000 laboratory-confirmed cases reported.
What are the symptoms of mpox infection?
Mpox causes signs and symptoms which usually begin within a week but can start 1–21 days after exposure.
Common mpox symptoms include a rash, fever, sore throat, headache, muscle aches, back pain, low energy and swollen lymph nodes.
The rash can appear on any part of the body. It starts as spots which turn into ulcers or small blisters filled with fluid. The blisters eventually form scabs and fall off. Some people may have one or a few blisters, whereas others can have hundreds.
Symptoms usually clear within a few weeks, however some people can become very sick and experience complications such as skin abscesses following bacterial infection, pneumonia, loss of vision, diarrhoea and vomiting, sepsis, encephalitis, and heart inflammation.
Mpox can be fatal in some cases. Children, pregnant people and people with weak immune systems, including people living with HIV, are at higher risk for serious illness and death due to complications from mpox.
How is CEPI responding to mpox?
CEPI’s goal is to generate data to expand access to currently licensed mpox vaccines and to also use the information from CEPI-supported R&D efforts to help inform the development of new vaccines against other deadly poxviruses. Ultimately we want to help end the current outbreak and ensure that we are better prepared to respond to subsequent mpox outbreaks.
CEPI first supported mpox vaccine R&D activities in 2022, investing in mpox antibody standards and assays, critical tools needed to support the development and assessment of mpox vaccine candidates.
In recent months, CEPI has ramped up its vaccine development efforts to help respond to the fast-spreading mpox outbreak severely affecting the DRC and other nations.
While three approved vaccines to protect people against mpox, the vaccines are not currently licensed for use in some of the at-risk population groups—like pregnant women, children and infants—who are most likely to suffer from serious complications from mpox infection, meaning that these groups remain unprotected and at risk of severe illness.
So, CEPI is working to fill in crucial vaccine R&D gaps and expand access to mpox vaccines to those most at risk, funding three groundbreaking studies in the DRC, Uganda and possible other countries that will provide pivotal data on the mpox vaccine developed by Bavarian Nordic in key populations:
- The first, to assess immunogenicity in children, which launched in October 2024.
- The second, to evaluate whether vaccination could reduce the risk of secondary mpox cases after someone comes into contact with a diagnosed case, launched in September 2024.
- The third to evaluate the performance of the vaccine in pregnant and breastfeeding women and infants under two years of age. The trial is set to launch in early 2025.
CEPI also supported the development of the WHO Mpox Research Roadmap which lists out the immediate next steps needed in research to contribute to controlling the outbreak. We are continuing to explore more opportunities that could generate additional data on mpox epidemiology and mpox vaccines.
In response to the current mpox outbreak, CEPI’s Regulatory Team has helped to collate evidence on the safety and efficacy of mpox vaccines for use and review by local regulators and decision makers with real-time updates as new data becomes available.
We are also supporting partners like Africa CDC and WHO with their outbreak response efforts and are part of the Access and Allocation Mechanism for mpox, set up to increase access to life-saving tools like vaccines, medicines and tests for people at highest risk. Working with vaccine manufacturers, CEPI is also exploring avenues to support both scale up and scale out of vaccine production to increase available supply.
Finally, to better prepare for responding to future mpox and poxvirus-related outbreaks, CEPI is supporting the development of potential new vaccine candidates, like BioNTech’s next-generation mRNA mpox vaccine which is in early clinical development.
Latest mpox news
Latest mpox news
New study to assess mpox vaccine in pregnant women and infants
The research could help expand vaccine access to these populations at risk of mpox complications but not currently eligible for vaccination.
Mpox – What it is, and what it is not
What is mpox? When did the latest mpox outbreak start? Where is it spreading? CEPI answers some of the most frequently asked online questions about this virus.
New trial to assess if mpox vaccination works after virus exposure
The evidence generated could be crucial in shaping mpox vaccination strategies to help tackle a large and deadly mpox outbreak escalating in the DRC.
The Poxviruses
The viral family of one of the most fearsome contagious diseases in human history
CEPI, UK MHRA, and UK Health Security Agency to advance key tools for Monkeypox vaccine research
Up to US$375k will be made available by CEPI for the development of a Monkeypox antibody standard and assays.
Could monkeypox give us an R&D blueprint to end pandemics?
Availability of smallpox countermeasures, developed to counter bioterrorism, also give the world the means to combat monkeypox and other orthopoxviruses. What if this approach could be applied to all viral families?
Bavarian Nordic and CEPI partner to advance Mpox vaccination in Africa
African trial could potentially support licensure of mpox vaccine in endemic countries and expansion of current regulatory approvals to include children
