The World Health Organization recommended testing two additional Ebola vaccine candidates, ChAdOx1 and mRNA-1469, in the ongoing Tumaini clinical trial in the Democratic Republic of the Congo. This marks the first time vaccines developed specifically against the Bundibugyo virus will undergo evaluation during an active outbreak.
The decision expands an ongoing multi-candidate evaluation designed to curb viral transmission in Central Africa. RTT News reported that the independent panel of experts notified the vaccine developers earlier this week. National authorities must grant regulatory clearance before the candidates enter active clinical administration in the field.
The trial relies on a ring-vaccination strategy. Public health workers vaccinate the primary contacts of confirmed patients, building a defensive immunological barrier around transmission chains. This methodology was successfully used during the Ebola outbreak in West Africa around 10 years ago.
Testing Vaccines Against the Bundibugyo Virus
- Ring Vaccination: A strategy where healthcare workers immunize close contacts of an infected patient to block the virus from spreading further through the community.
- Viral Strain Targeting: The trial features vaccines specifically developed to protect against the Bundibugyo virus, marking the first time such vaccines will be tested during an active outbreak.
- Candidate Vaccines: Among the newly integrated options are Moderna’s mRNA-1469 alongside ChAdOx1, which stems from a joint effort between the Serum Institute of India and the University of Oxford.
Expanding the Tumaini Trial in the Democratic Republic of the Congo
The Tumaini clinical trial is being conducted by the Democratic Republic of the Congo’s Institut National de Recherche Biomédicale. Partner institutions include the University of Antwerp in Belgium, Médecins Sans Frontières, Epicentre, the Institute of Tropical Medicine in Antwerp, and the Africa Centres for Disease Control and Prevention. Financial backing from the Coalition for Epidemic Preparedness Innovations helped accelerate the development of the vaccines.
Four vaccination cohorts are already established, with more being planned. To evaluate its potential cross-protection against the Bundibugyo strain, Ervebo—previously shown to offer protection against the Zaire ebolavirus during an extensive trial in Guinea—serves as the initial vaccine under evaluation in the Tumaini study.
| Vaccine Candidate | Developer / Institution | Target Strain | Trial Phase / Status |
|---|---|---|---|
| Ervebo | Effective against Zaire ebolavirus | Bundibugyo virus (testing protection) | Active in Tumaini trial |
| ChAdOx1 | University of Oxford / Serum Institute of India | Bundibugyo virus | Recommended for inclusion |
| mRNA-1469 | Moderna | Bundibugyo virus | Recommended for inclusion |
Parallel Therapeutic Trials for Confirmed Infections
Alongside prophylactic vaccine testing, clinical investigators are evaluating direct antiviral treatments for patients who contract the disease. Backed by the WHO and launched in July, the PARTNERS study examines whether patient survival rates for confirmed Bundibugyo virus disease can be enhanced using remdesivir, the monoclonal antibody MBP134, or a regimen combining both treatments.
Maftivimab will soon be included in the trial for further evaluation. Trials are additionally assessing obeldevisir independently to see if it can successfully ward off the illness among individuals who have come into contact with the virus.
Expecting Preliminary Findings from Treatment Studies
Preliminary findings from the treatment studies are expected in the coming months. Findings from the vaccine trial are likely to be available in early 2027.
References
- Institut National de Recherche Biomédicale (INRB) – DRC clinical trial updates.
- Coalition for Epidemic Preparedness Innovations (CEPI) – Vaccine development and acceleration metrics.
Earlier coverage: WHO approves clinical trials for two new Ébola vaccines in DRC
