The trial, named Tumaini, meaning “hope” in Swahili, began on Friday, October 23, 2026, in Bunia, the capital of Ituri Province, following the vaccination of its first participant.

WHO Director-General, Tedros Ghebreyesus, announced the development on his official X account, describing the study as an important step towards finding effective protection against the virus.

According to Tedros, the trial will assess whether vaccine candidates developed against the Bundibugyo strain can provide protection and help health authorities respond more effectively to the ongoing outbreak.

The first vaccine being evaluated is Ervebo, which is licensed to prevent Ebola disease caused by the Zaire strain. Researchers will investigate whether it can also offer protection against the Bundibugyo strain, for which no vaccine has been approved.

Two additional candidates specifically developed for the Bundibugyo virus are expected to join the study. They are being developed by Moderna and the University of Oxford in collaboration with the Serum Institute of India.

The trial will assess the safety, immune responses and effectiveness of the vaccine candidates. It will use an adaptive study design that allows multiple vaccines to be evaluated within a common framework.

Researchers will also employ a ring vaccination approach, focusing on people who have had contact with confirmed Ebola cases and others considered to be at high risk of infection.

The study is being led by Congolese health authorities and research institutions, with technical and scientific support from the WHO and other international partners.

The launch comes as DR Congo continues to battle a major outbreak of Bundibugyo virus disease, which was officially declared on May 15, 2026. The WHO subsequently declared the outbreak a Public Health Emergency of International Concern, highlighting the need for coordinated international action.

Figures released by organisations supporting the trial showed that, as of October 21, DR Congo had recorded 9,552 cases and 4,602 deaths associated with the outbreak.

The scale of the outbreak has increased the urgency of efforts to identify effective vaccines and strengthen other response measures, including surveillance, contact tracing and community engagement.

Although Ervebo is already licensed for another Ebola strain, its inclusion in the Tumaini trial is intended to establish whether it can protect against Bundibugyo virus disease. Its existing approval does not mean that it has been proven effective against the strain responsible for the current outbreak.

The two Bundibugyo-specific candidates are expected to provide additional options for evaluation as preparations for their inclusion in the trial continue.

The study is co-led and co-sponsored by the Democratic Republic of the Congo’s National Institute of Biomedical Research and the University of Antwerp’s Institute of Tropical Medicine. The Congolese Ministry of Health provides national leadership and oversight.

The findings could help guide future vaccination strategies against Bundibugyo virus disease, although researchers will need to establish the safety and effectiveness of the candidates before conclusions can be drawn.

Reporting by TalkNaijaMedia