The World Health Organization began the Tumaini trial in Bunia, capital of Ituri province, marking the first time an Ebola vaccine has been tested during an active outbreak. Director-General Tedros Adhanom Ghebreyesus confirmed on Friday that initial participants received the Ervebo vaccine, a drug approved previously for the Zaire strain. The core question is whether it can stop the Bundibugyo virus currently ravaging the region.
The stakes are brutal. DRC declared its 17th Ebola outbreak in May, and the numbers have since spiraled into a catastrophe: more than 9,700 reported cases and over 4,600 deaths. It is now the worst Ebola crisis in the country’s history. The virus has even crossed borders, appearing in four nations across eastern, central, and western Africa, prompting the WHO to declare a public health emergency of international concern.
The trial isn't just about Ervebo. It is a single framework designed to evaluate multiple candidates simultaneously using a ring vaccination strategy, targeting close contacts of infected individuals. Two experimental vaccines specifically built for Bundibugyo will join the study soon. One is an adenoviral vector candidate, ChAdOx1, from the University of Oxford. The other is an mRNA vaccine from US biotech firm Moderna. Both are funded by the Coalition for Epidemic Preparedness Innovations (CEPI).
Unusually, the trial includes pregnant women and children aged 12 and above. This decision will generate critical safety and efficacy data for demographics historically excluded from such high-risk studies. Chikwe Ihekweazu, WHO’s emergencies director, stated the goal is to produce robust evidence on protection levels. The findings will dictate whether these vaccines can be deployed at scale to contain the spread.
The next phase hinges on the arrival of the Oxford and Moderna candidates. Until they enter the trial, the focus remains on whether Ervebo provides any shield against the current strain. The results will determine the global response strategy for this unprecedented geographical spread of Ebola.