Health
New Ebola Vaccines Enter Multi‑Vaccine Trial as DRC Outbreak Surpasses 10,000 Cases
With more than 10,500 confirmed infections and over 5,000 deaths, the Democratic Republic of the Congo has added two novel Ebola vaccine candidates to the Tumaini ring‑vaccination trial, aiming to curb the Bundibugyo outbreak.
Outbreak magnitude and existing interventions
The current Ebola outbreak in the eastern Democratic Republic of the Congo, driven by the rare Bundibugyo virus, has persisted for almost six months. As of 1 November, health authorities have recorded more than 10,500 laboratory‑confirmed cases and 5,126 deaths, making it the largest Ebola episode in the country’s history. The epicentre remains Bunia, the capital of Ituri province, where the World Health Organization (WHO) is already testing the Ervebo vaccine—originally designed for the Zaire strain—to see whether it offers protection against Bundibugyo. These figures underscore the urgent need for additional tools to halt transmission.
Introducing ChAdOx1 and mRNA‑1469 vaccines
The trial will now evaluate two new candidates: ChAdOx1, a viral‑vector vaccine co‑produced by the University of Oxford and the Serum Institute of India, and mRNA‑1469, an mRNA formulation developed by Moderna. Both candidates were selected after WHO’s independent Technical Advisory Group on Candidate Vaccines Prioritisation reviewed the available data and recommended them for further study. Their inclusion marks the first time that vaccines specifically engineered for the Bundibugyo species are being assessed during an active outbreak, offering a potential scientific breakthrough that could expand the arsenal beyond the existing Zaire‑focused products.
Tumaini trial’s ring‑vaccination strategy
The multi‑vaccine trial, named Tumaini—Swahili for “hope”—was launched on 23 October in Bunia and uses a ring‑vaccination approach that targets contacts of confirmed cases. So far four vaccination rings have been established, with additional rings being prepared as more contacts are identified. By testing several candidates within the same trial, WHO aims to generate comparative data quickly and to identify the most effective option for Bundibugyo. The strategy builds on the successful ring‑vaccination study that proved Ervebo’s efficacy in Guinea during the West Africa epidemic, and it is supported by a coalition of partners working to contain the outbreak.