Japan has donated three million doses of the LC16m8 vaccine, a live-attenuated vaccine licensed in Japan for smallpox and used previously during mpox outbreaks, which is considered safe and effective even for HIV-positive individuals.

A major mpox outbreak in the Democratic Republic of Congo (DRC), declared a public health emergency, has prompted a new study to evaluate the real-world effectiveness and safety of the LC16m8 mpox vaccine in African populations, including children over one year old.

Funded by CEPI with up to $10.4 million, the study will be led by the International Vaccine Institute in collaboration with the DRC's INRB and Japan's JIHS, focusing on high-transmission areas within Équateur Province.

Key stakeholders, including the International Vaccine Institute, INRB, JIHS, and CEPI, are working together to strengthen local research capacity and improve outbreak response efforts.

Researchers will monitor vaccinated populations in hotspot zones to assess infection rates and safety, with particular attention to children, as the vaccine is approved for all ages in Japan.

Officials from Japan, the Africa CDC, and local health authorities are optimistic that the research will enhance understanding of the vaccine’s performance and support effective vaccination strategies.

Experts see the LC16m8 vaccine as a crucial tool in combating the epidemic, especially to protect vulnerable groups like children, and to bolster Africa’s capacity to respond to future health emergencies.

This initiative marks the first effort in Africa to gather real-world data on the vaccine’s use against mpox, which will inform future vaccination policies and prioritization.

Findings from the study are expected to guide vaccination priorities and support regulatory decisions on broader use of LC16m8 in other countries, contributing to global preparedness.

The study will evaluate vaccine effectiveness by monitoring infection rates among vaccinated individuals and will collect safety data through observational monitoring of a subset of participants.

The research aligns with WHO, Africa CDC, and DRC health authorities’ recommendations to gather more data during outbreaks, with the DRC becoming the first African country to collect field data on LC16m8.

The ongoing mpox outbreak, declared a health emergency by WHO and Africa CDC in August 2024, continues to pose a significant health threat in Africa.