KINSHASA/OSLO/ TOKYO, 11 SEP—New research due to launch in the Democratic Republic of the Congo (DRC) will provide important real-world data on the performance of the LC16m8 mpox vaccine in African populations, amid a major outbreak of the deadly virus which remains a continental public health emergency.
“The vaccination campaign in the DRC provides us with a vital opportunity to gather insights into how effective the well-established LC16m8 vaccine is against preventing mpox disease in a high transmission setting, including in children”said Dr. Richard Hatchett, CEO of the Coalition for Epidemic Preparedness Innovations (CEPI) who are funding the study. “This could help guide how the vaccine can be used to have the most impact in the future. Research will also strengthen local scientists’ experience in rapidly generating real-world data during outbreaks which could support faster and more efficient responses to future epidemic threats in the region.”
LC16m8 is a live-attenuated vaccine produced by the Japanese manufacturer KM Biologics, a Meiji Group company, and licensed in Japan for decades against smallpox. It has also been used in Japan during previous mpox outbreaks, where it has been shown to be safe and effective, including in people with well-controlled HIV. LC16m8 is now being rolled out for emergency use in the DRC, alongside another licensed mpox vaccine, in response to the outbreak. Three million doses of LC16m8 are being donated to the DRC by the Government of Japan to protect at-risk populations from the virus.
Pending regulatory and ethics approvals and follow-up agreements for the study, an international research consortium will leverage the vaccination campaign to generate real-world evidence on the safety and effectiveness of the vaccine against mpox in affected populations in sub-Saharan Africa, including in infants and children aged one year and above.
CEPI is providing up to US $10.4 million to support the study (NCT07093489) which is expected to launch in the Autumn. The International Vaccine Institute (IVI) will serve as the study sponsor while the Institut National pour la Recherche Biomédicale (INRB) in the DRC will act as the co-sponsor. Supported by the DRC’s Ministry of Health and the Institut National de Santé Publique (INSP) which regulates Mpox outbreak research, the INRB will also assume the role of principal investigator with the Japan Institute for Health Security (JIHS) as co-investigator.
The expert team is set to assess the effectiveness of the Lc16m8 vaccine by looking at how many people become infected with mpox after being vaccinated in selected health zones considered hot spots for mpox cases in Équateur province, Northwestern DRC. Additional data on the vaccine’s safety will be collected through monitoring a subset of participants taking part in the observational study.
The data generated is expected to inform vaccination and mpox management strategies in the DRC and other mpox endemic regions, including, for example, the age groups that may benefit most from the vaccine and could be prioritised for vaccination. The findings could also contribute evidence for policy and regulatory decisions on the use of LC16m8 in other countries.
The new research supports recommendations from the DRC’s Ministry of Health, the World Health Organization and Africa CDC to prioritise collecting additional data on the safety and performance of mpox vaccines in outbreaks.
His Excellency Samuel Roger Kamba, Minister of Health of the DRC, said “The epidemiological data on Mpox have enabled us to support the response with vaccination of the populations. With this collaborative research, the DRC will be the first African country to collect essential field data on the use of the LC16m8 vaccine against Mpox.”
Dr. Manabu Sumi, Director-General of the Department of Infectious Disease Prevention and Control at the Ministry of Health, Labour and Welfare of Japan, said “The Ministry is pleased that LC16m8 will participate in this important clinical trial, aiming to establish the evidence supporting its role in the fight against mpox. As the world’s only mpox vaccine currently approved for use in children, Japan’s LC16m8 has the capacity to help protect people of all ages. Building on the findings of this trial and Japan’s accumulated experience, the Ministry looks forward to working with international partners to further enhance LC16m8’s contribution to global preparedness and response efforts against mpox.”
Dr Jean Kaseya, Africa CDC Director General, said “This study is a vital step in protecting Africa’s most vulnerable, especially children, from mpox. By turning science into action, we are building the evidence needed to guide vaccination and strengthen health security across the continent.”
Dr. Florian Marks, Deputy Director General of Epidemiology, Public Health, Impact at the International Vaccine Institute, said “This study in the DRC is an important opportunity to evaluate the LC16m8 vaccine in an outbreak setting, helping protect communities now while generating essential evidence on the vaccine’s safety and effectiveness for the future. In close partnership with INRB, JIHS, CEPI, and local health teams, we are also working to strengthen local research capacity so that communities are more experienced and better equipped to respond to future health emergencies.”
Prof Dr. Muyembe, General Director of INRB and Principal Investigator, said “It is through scientific research with our different partners that we will be able to highlight the scientific evidence on the effectiveness of the LC16m8 vaccine against Mpox. The results generated by study will serve as an effective guide for future Mpox outbreak.”
Dr. Norio Ohmagari, Specially Appointed Deputy Hospital Director and Director of the Department of Infectious Diseases and Disease Control and Prevention Center at the Japan Institute for Health Security (JIHS), said: “As Co-Principal Investigator, I am honored to collaborate with INRB, IVI, and CEPI to build rigorous real-world evidence on the effectiveness and safety of LC16m8 across the life course, including children. These data will directly inform vaccination policy and strengthen outbreak response capacity in the region.”
Dr Mugen Ujiie, Chief of Travel Clinic and Director of Vaccination Support Center at the Japan Institute for Health Security (JIHS), said “Japan, through JIHS, is proud to support this collaborative effort to generate real-world evidence on the LC16m8 vaccine—including in children—to better protect communities from mpox. The findings will help inform equitable and effective vaccination strategies across affected regions.”
Dr. Dieudonné Mwamba, General Director of INSP said “I express my satisfaction with this inter-institutional collaboration on evaluating the efficacy of the LC16m8 vaccine, as vaccination is one of the key pillar in responding to epidemics, particularly Mpox.”
Mpox (formerly Monkeypox) is a contagious infectious disease caused by the mpox virus, which is a member of the Poxvirus family. There are two different known forms, or clades, of the mpox virus known as clade I and clade II. Most people infected with mpox suffer with flu-like symptoms such as fever, headache, muscle aches, low energy and swollen lymph nodes, as well as a skin rash featuring pus-filled lesions or blisters. In severe cases it can be deadly.
The WHO and Africa CDC declared an ongoing outbreak of mpox was both a continental and global health emergency in August 2024. The WHO’s declaration of a Public Health Emergency of International Concern, or PHEIC, was the second time in two years that mpox has been classified as an international emergency. As of September 2025, WHO and Africa CDC identified that Mpox remains a continental emergency in Africa.
Mpox is one of CEPI’s priority pathogens. CEPI is advancing research to improve our understanding of mpox vaccines and increase access to mpox vaccines for affected populations to help respond to the current mpox outbreak and to prepare for future poxvirus outbreaks.
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Notes to Editors
The freeze-dried smallpox and mpox vaccine prepared in cell culture LC16 “KMB” (LC16m8 vaccine) was licensed for use against Mpox in Japan in 2022. Lc16m8 received WHO Emergency Use Listing in November 2024. It is currently the only licensed/EUL mpox vaccine indicated for all age groups, including children aged 1 year or older who are among the most affected by the ongoing mpox outbreak in the DRC. The vaccine received national Emergency Use Authorisation in the DRC in June 2024.
About CEPI
CEPI is an innovative partnership between public, private, philanthropic, and civil organisations. Its mission is to accelerate the development of vaccines and other biologic countermeasures against epidemic and pandemic threats so they can be accessible to all people in need. CEPI has supported the development of more than 70 vaccine candidates or platform technologies against multiple known high-risk pathogens or a future Disease X. Central to CEPI’s pandemic-beating plan is the ‘100 Days Mission’ to accelerate the time taken to develop safe, effective, globally accessible vaccines against new threats to just 100 days. Learn more at CEPI.net.
Image Credit and Caption
Doctor from UNICEF mission doing the tetanus vaccination-DRC September 2008_EDITORIAL USE ONLY.jpg