Since June 2023, the majority of MPOX cases and deaths in the Democratic Republic of Congo have been children.
Researchers at McMaster University have received $6.7 million in funding from the Coalition for Epidemic Preparedness Innovations (CEPI) and the Canadian Institutes of Health Research to evaluate the effectiveness of a smallpox vaccine in preventing smallpox after exposure.
Starting in August, the Smallpox Post-Exposure Prophylaxis with Smallpox Vaccine: A Cluster Randomized Controlled Trial (SMART) will evaluate the effectiveness of the Bavarian-Nordic Smallpox Vaccine (MVA-BN) in more than 1,500 participants from households with laboratory-confirmed smallpox infection in facilities in the Democratic Republic of the Congo (DRC), Uganda and Nigeria.
Monkeypox is a disease caused by infection with a virus called the monkeypox virus, which is in the same family as the virus that causes smallpox. Symptoms include fever, headache, and painful lesions. In some cases, the disease can lead to bronchopneumonia, sepsis, encephalitis, loss of vision, and even death.
Between June 2023 and 2024, the Democratic Republic of the Congo has reported more than 7,000 suspected and confirmed cases and more than 300 deaths, the majority of them among children.
The currently circulating MPOX strain is known as clade I and is estimated to be fatal in up to 12% of cases.
The MVA-BN vaccine is currently administered prophylactically to individuals at high risk of contracting MPOX, such as healthcare workers, but in resource-poor areas, vaccination with MPOX after infection could potentially quell infection and speed recovery.
Selected participants will receive a post-exposure vaccination of either the MVA-BN smallpox vaccine or a control vaccine, and four weeks later the scientists will compare the number of participants in each group who get smallpox, and follow up with those who get sick to measure the severity of their symptoms.
The researchers believe that evidence from this trial may help shape MPOX vaccination strategies to address the MPOX epidemic in the DRC and neighboring countries.
CEPI Chief Executive Richard Hatchett commented: “Healthcare workers are typically vaccinated before they are exposed to infection, but post-exposure vaccination allows for a more targeted approach, minimising the use of vaccine supplies.”
