The trial, named Tumaini, meaning “hope” in Swahili, is expected to begin in the coming weeks, subject to the necessary ethical and regulatory approvals. It will assess the safety, immunogenicity and efficacy of vaccine candidates, including Ervebo, as researchers seek to address the lack of an approved vaccine specifically targeting the Bundibugyo strain.
CEPI disclosed this in a statement published on its website and obtained by the News Agency of Nigeria (NAN) on Tuesday.
The planned study is intended to support the DRC government-led outbreak response while generating scientific evidence that could expand the options available to health authorities confronting future outbreaks of the virus.
“There is currently no approved vaccine against Bundibugyo virus,” CEPI said, highlighting a significant gap in the tools available to prevent the disease.
The organisation said the World Health Organization’s Technical Advisory Group on Candidate Vaccine Prioritisation had recommended that Ervebo be evaluated in a Phase Three trial, with vaccines specifically developed against Bundibugyo virus to be included when they become available.
Ervebo to undergo evaluation against Bundibugyo virus
Although Ervebo is licensed to prevent Ebola virus disease caused by the Zaire strain, its effectiveness against Bundibugyo virus has yet to be established.
The distinction is important because Ebola virus disease can be caused by different viruses within the Orthoebolavirus genus, and protection against one strain cannot automatically be assumed to provide protection against another.
CEPI said Ervebo was likely to be the first vaccine to enter the Tumaini trial, offering researchers an opportunity to evaluate its potential role in addressing the Bundibugyo outbreak.
However, the vaccine's inclusion in the study does not mean it has already been shown to protect against Bundibugyo virus. Its safety and immune response, as well as its potential efficacy, will need to be assessed through the clinical trial process.
The study is expected to contribute evidence that could guide future decisions on the use of vaccine candidates against the strain, depending on the results and applicable regulatory requirements.
Adaptive trial design to accelerate research
The Tumaini trial will use an adaptive platform design, allowing multiple vaccine candidates to be evaluated within a single clinical trial framework.
According to CEPI, the approach could save time during an outbreak by enabling researchers to assess different candidates in parallel rather than conducting entirely separate studies for each vaccine.
The trial will also use a ring vaccination strategy, targeting people who have been in contact with confirmed cases and other contacts considered at high risk of infection.
Ring vaccination is designed to create a protective buffer around detected cases by offering vaccination to eligible contacts and, where appropriate, contacts of those contacts. This approach can help researchers assess interventions in outbreak settings while supporting efforts to limit further transmission.
The success of the strategy will depend on the trial's implementation, community engagement, timely identification of contacts and compliance with the required scientific and ethical safeguards.
DRC institutions and African partners to lead implementation
The Institut National de Recherche Biomédicale (INRB) and the University of Antwerp’s Global Health Institute will lead and co-sponsor the study, according to CEPI.
The DRC Ministry of Health will provide national leadership and oversight, ensuring that the research is integrated into the country's public health response.
The Africa Centres for Disease Control and Prevention (Africa CDC) will play a strategic role in advancing African-led clinical research, strengthening regional coordination and helping ensure that emerging scientific evidence informs public health decisions.
CEPI said Africa CDC's involvement would also support the wider Ebola response and efforts to promote timely and equitable access to successful vaccine candidates.
Other partners include Epicentre, Médecins Sans Frontières and the Institute of Tropical Medicine Antwerp.
CEPI will contribute funding, scientific expertise and operational support to facilitate the trial.
The collaboration brings together national health authorities, African public health institutions and international research organisations, with the aim of generating evidence that can inform outbreak response and future preparedness.
Two Bundibugyo-specific vaccines undergoing early trials
Alongside the evaluation of Ervebo, researchers are developing vaccines specifically designed to target Bundibugyo virus.
CEPI said two such candidates, developed by Moderna and the University of Oxford in collaboration with the Serum Institute of India, were undergoing Phase One clinical trials.
Phase One studies generally focus on assessing initial safety and examining how the human immune system responds to a vaccine candidate. Further studies are needed to establish whether a candidate can provide protection against the disease.
The development of these vaccines could eventually expand the range of options available to health authorities, particularly because existing licensed Ebola vaccines target a different strain.
CEPI has been supporting Bundibugyo-specific vaccine research at different stages of development, with the broader objective of improving the world's ability to respond rapidly to outbreaks of emerging infectious diseases.
The progress of the candidates through clinical trials will be important in determining whether they can advance towards wider evaluation and, potentially, regulatory approval.
Funding supports preparedness against future outbreaks
The Tumaini trial is being funded through CEPI's Bundibugyo virus vaccine development programme, backed by the European Commission, the United States Department of State, the Fund for Science and Technology, and CEPI's core funding.
The programme forms part of broader international efforts to strengthen vaccine research and ensure that potential medical countermeasures can be evaluated quickly when outbreaks occur.
For the DRC, where the current outbreak has placed substantial pressure on public health responders, the trial could provide an important opportunity to assess additional tools for controlling the disease.
However, the trial's launch remains subject to ethical and regulatory approval, and its findings will need to establish whether the vaccine candidates are safe and effective against Bundibugyo virus.
As preparations continue, the Tumaini study represents a significant step in efforts to address the shortage of vaccines specifically targeting the strain, while strengthening collaboration between African institutions and international research partners.
Its eventual results could help shape future vaccination strategies and preparedness plans for outbreaks of Bundibugyo virus, although the extent of its impact will depend on the evidence generated and subsequent regulatory decisions.