- CEPI-backed studies will analyse blood samples from thousands of people who have already been vaccinated against Zaire ebolavirus, with first results expected within months
Oslo, 20 August 2026: CEPI is providing US$4.17 million to four research projects designed to assess whether vaccines already or previously licensed against Zaire ebolavirus—including Ervebo—could offer protection against Bundibugyo ebolavirus, the virus behind the rapidly escalating outbreak in the Democratic Republic of the Congo, which was declared a Public Health Emergency of International Concern by the World Health Organization (WHO) in May 2026. Awardees include research groups led by UCLA (USA); Institute of Tropical Medicine (Antwerp); University of Oxford (UK); and MRC-University of Glasgow Centre for Virus Research (UK).
“There is no licensed vaccine against Bundibugyo virus. CEPI is funding multiple Bundibugyo vaccine candidates to address this gap, but even on the most compressed timelines those vaccines will not be available for the earliest phase of this outbreak”, explains Dr Richard Hatchett, CEO of CEPI. “However, vaccines do exist for the related Zaire ebolavirus, including Ervebo. Given the recent announcement that Ervebo will be deployed for emergency use against Bundibugyo virus, these CEPI-backed studies will be all the more important to inform on how we can make the best use of the existing vaccine.”
How the studies support vaccine development
The research teams will analyse stored blood samples from individuals vaccinated with licensed/previously licensed vaccines against Zaire ebolavirus either in previous vaccination campaigns and/or clinical trials. They aim to characterise vaccine-induced immune responses and assess cross-reactivity of antibody responses against Bundibugyo ebolavirus.
The critical data that these serology studies will provide will help establish and standardise tests for antibodies against Bundibugyo virus and use longitudinal samples to define the dynamics and durability of these responses. Data from these studies will also aid interpretation of immune responses in clinical trials, help assess whether Bundibugyo-specific antibodies are associated with protection, and inform future vaccination strategies and evaluation of Bundibugyo-specific and broadly protective filovirus vaccines.
In recent weeks, new data have emerged indicating that further prospective evaluation of Ervebo is warranted. Consequently, the WHO Technical Advisory Group on Candidate Vaccine Prioritization (TAG-CVP) has recommended that Ervebo be evaluated in a Phase 3 clinical trial, in addition to Bundibugyo-specific vaccine candidates when they are ready. The DRC authorities and Africa CDC have announced plans to deploy Ervebo to priority groups under protocol-governed expanded use. The CEPI-backed studies will rapidly generate additional evidence to help fill outstanding gaps in knowledge, and contribute to decision making about how Ervebo can be used in this and future responses.
About the studies
UCLA Fielding School of Public Health (US$2.05 million): This study will draw on long-running cohorts of people who received either of the licensed/previously licensed Zaire ebolavirus vaccines (Ervebo and Ad26.ZEBOV/MVA-BN-Filo [Zabdeno/Mvabea]). Drawing from data gathered from more than 1700 participants and around 1800 stored serum samples, researchers will assess immune responses to determine whether these vaccines trigger antibody responses against Bundibugyo virus. Research will be done in collaboration with INRB, the University of Manitoba and Public Health Agency of Canada’s National Microbiology Laboratory, the University of Texas Medical Branch, and Columbia University.
- Prof Anne W. Rimoin, Professor of Epidemiology at the UCLA Fielding School of Public Health, said: “When an outbreak is moving this quickly, we cannot afford to start from zero. Through more than two decades of collaboration, UCLA and INRB have built longitudinal cohorts and laboratory expertise that we can draw on now, together with our scientific partners, to rapidly generate rigorous evidence to inform vaccine evaluation. This work also builds on longstanding scientific partnerships and infrastructure that will help us respond more effectively to this and future Ebola outbreaks.”
Institute of Tropical Medicine (ITM), Antwerp (US$1.02 million): The project (EBO-BOOST-BRIDGE), led by ITM and in collaboration with INRB, will build on the CEPI-funded EBO-BOOST Phase II trial and its biobank of samples from over 600 participants. Researchers will undertake antibody testing against all Orthoebolavirus species and Marburg virus, prioritising tests for Bundibugyo ebolavirus. They will examine which vaccines potentially provide cross-protection against Bundibugyo virus and identify vaccination regimens that might be associated with broad and durable cross-reactive immune responses. Part of the award will transfer these laboratory methods to INRB in DRC, harmonising their laboratory capacity with that of CEPI’s Centralized Laboratory Network and international antibody reference standards. First antibody results are expected within two to six months.
- “Thanks to our existing database of blood samples from people vaccinated against Zaire ebolavirus, and our long-standing partnership with INRB, we do not have to start entirely from scratch when an outbreak like this occurs,” says ProfWim Adriaensen, Professor of Clinical Immunology at ITM and principal investigator of the EBO-BOOST-BRIDGE study.
- “This foundation gives us a valuable head start in finding out whether existing Ebola vaccines can provide cross-protection against Bundibugyo ebolavirus and other known ebolavirus species, adds ProfSabue Mulangu, Professor of Clinical Immunology at INRB. “This helps us respond more quickly to future outbreaks caused by less well-known species.”
University of Oxford, Nuffield Department of Medicine’s Centre for Human Genetics and Pandemic Sciences Institute (US$975,000): The Oxford team will test blood samples from recipients of the Ervebo vaccine and survivors ofZaire ebolavirus disease. Findings will indicate whether immunity developed as a result of vaccination or natural infection toZaire ebolavirus could potentially provide protection against the Bundibugyo virus, including the current outbreak and a strain associated with the 2007 outbreak.
- Prof Miles Carroll, Professor of Emerging viruses, University of Oxford, and Lead investigator, said: “We are delighted to receive this investment from CEPI and to be collaborating with our Guinean and Belgian colleagues in this important research project. We believe our study will provide critical information on the ability of naturally acquired and vaccine-induced immunity to Ebola virus, to protect against infection with Bundibugyo virus from the current outbreak. Such data is critical for rapid vaccine deployment decision making.”
MRC-University of Glasgow Centre for Virus Research (US$120,000): The team will draw on two existing cohorts: the Glasgow Ebola Vaccine (GEV) study of close contacts vaccinated against Zaire ebolavirus, and the Arboviral Infection study of Ugandan healthcare workers vaccinated during the 2019 outbreak response. The study will be done in collaboration with the Uganda Virus Research Institute as a sub-awardee and will help establish whether antibodies generated in response to Ervebo vaccination also recognise Bundibugyo virus.
- Prof Brian Willett, Professor of Viral Immunology at The MRC-University of Glasgow Centre for Virus Research said:“Studies that measure virus-specific antibodies provide a critical tool for identifying evidence of virus exposure, revealing patterns of virus circulation, identifying high-risk groups and geographic hotspots, and improving understanding of transmission dynamics. The Centre for Virus Research Preparedness team is developing diagnostic tests for high-priority pathogens such as Bundibugyo virus, thereby supporting more effective surveillance, outbreak preparedness, and public health interventions in regions at risk of viral emergence. Funding from CEPI will enable the team to investigate the level of cross-protection afforded by existing Ebola vaccines, and their likely effectiveness against emerging filoviruses.”
These awards were selected through CEPI’s Call for Proposals focussed on the generation of evidence to support Bundibugyo vaccine R&D decision making, published in June 2026. All partners are committed to CEPI’s Equitable Access Policy and will support publication of the project results in open access journals for the benefit of the global scientific community
To date, CEPI’s Bundibugyo virus vaccine development programme receives funds from the European Commission through its 2026 grant under Horizon Europe to CEPI, the U.S. Department of State and CEPI’s existing core funding.
About CEPICEPI 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. Central to CEPI’s pandemic-beating plan is the ‘100 Days Mission’ to develop safe, effective and accessible vaccines against new threats in just 100 days. CEPI is seeking $2.5 billion to execute CEPI 3.0, its 2027-2031 strategy which will systematically reduce the likelihood, impact and cost of epidemics and pandemics by driving the 100 Days Mission towards an operational reality. Learn more at CEPI.net.
About UCLA Fielding School of Public HealthThe UCLA Fielding School of Public Health, founded in 1961, is dedicated to enhancing the public’s health by conducting innovative research, training future leaders and health professionals from diverse backgrounds, translating research into policy and practice, and serving our local communities and the communities of the nation and the world. The school has more than 1,000 students from 25 nations engaged in carrying out the vision of building healthy futures in greater Los Angeles, California, the nation and the world.
About Institute of Tropical Medicine (ITM), AntwerpTropical diseases, HIV/AIDS, tuberculosis and poor health care influence the life of billions. Through fundamental and applied research, innovation, advanced education and expert services, the Institute of Tropical Medicine in Antwerp, Belgium (ITM) works to advance medical science and improve health for all. Founded in 1906, ITM is an independent centre of expertise in global health, tropical medicine and infectious diseases, with a particular focus on health challenges affecting underserved populations and low- and middle-income countries. Its work spans biomedical sciences, clinical sciences and public health, from laboratory and clinical research to disease prevention, health systems and policy. ITM works closely with a long-standing network of 26 partner institutions in 19 countries.
About The Pandemic Sciences Institute, University of OxfordThe Pandemic Sciences Institute (PSI) is an interdisciplinary research institute at the University of Oxford, dedicated to confronting the challenge of epidemic and pandemic infectious diseases. We work with academia, industry and public health organisations across the world to create science-led innovations, accelerate understanding, and develop new diagnostics, treatments, vaccines and disease control tools. Launched in 2022, PSI brings together researchers from across all four academic divisions of the University of Oxford: Medical Sciences; Mathematical, Physical and Life Sciences; Social Sciences; and Humanities. It is hosted by the Nuffield Department of Medicine. Find out more: www.psi.ox.ac.uk.
About the MRC-University of Glasgow Centre for Virus ResearchThe CVR is the UK’s national centre of excellence for human virology research. Established in 2010 as a partnership between the University and the Medical Research Council (MRC), its mission is to improve global health and preparedness for viral threats by carrying out fundamental research on viruses and viral diseases, and translating this knowledge into advances for global health and societal benefit. The CVR also contributes to sovereign capabilities in epidemic preparedness, bio-surveillance, and biosecurity. Researchers at the CVR have made significant contributions to the study of multiple important viruses including influenza, AAV2-linked paediatric hepatitis, mpox, rabies, dengue fever, Ebola, Zika, hepatitis C and SARS-CoV-2. In addition, the CVR houses world-class facilities including comprehensive containment level 3 (CL3) laboratories, state-of-the-art cryo-EM microscopes and a drug-resistance screening hub.
Media contacts
CEPI[email protected] | +44 7387 055214
UCLA Fielding School of Public HealthBrad Smith (Director of Public Relations) [email protected] | +1 424.440.3051
Institute of Tropical Medicine (ITM), AntwerpAnna Dams (Press Officer) [email protected] | +32 477 45 88 38
The Pandemic Sciences Institute, University of Oxford[email protected] | +44(0)1865 612102
MRC-University of Glasgow Centre for Virus Research[email protected] or [email protected]
Photo credit: National Institute of Allergy and Infectious Diseases.
