WHO Launches Landmark Ebola Vaccine Trial in DR Congo to Combat Widespread Outbreak

The World Health Organization (WHO) has initiated the first clinical trial for an Ebola vaccine within the Democratic Republic of Congo (DRC) amidst the ongoing outbreak. WHO Director-General Tedros Adhanom Ghebreyesus announced on social media that participants in Bunia, the capital of Ituri province and the outbreak's epicentre, received the Ervebo vaccine. This trial aims to assess if Ervebo, already approved for the Zaire strain, offers cross-protection against the Bundibugyo species responsible for the current epidemic. "This trial will help us understand whether any of the vaccine candidates designed for Bundibugyo virus work," stated the WHO chief on X. He added, "WHO is supporting this DRC-led effort to find answers and save lives." The DRC declared its 17th and most severe Ebola outbreak in May, which has since resulted in over 9,700 cases and more than 4,600 deaths. In response, the WHO declared a public health emergency of international concern, its second-highest alert level. The current outbreak has spread to four countries across eastern, central, and western Africa, marking the widest geographic distribution of any Ebola outbreak on the continent to date.

The 'Tumaini trial' is designed as a single framework capable of testing the safety, efficacy, and immunogenicity of multiple vaccines. It will employ a ring vaccination strategy, immunizing high-risk contacts of infected individuals. The trial is set to include two candidate vaccines specifically targeting the Bundibugyo strain, which are currently progressing through earlier, smaller-scale clinical trials. One is a ChAdOx1 adenoviral vector vaccine developed by the University of Oxford, and the other is an mRNA technology-based vaccine from Moderna. Both have received funding from the Coalition for Epidemic Preparedness Innovations (CEPI) and are expected to join the trial shortly, according to CEPI. Notably, the trial will include pregnant women and children aged 12 and older, aiming to gather crucial evidence for populations often excluded from clinical studies. WHO emergencies director Chikwe Ihekweazu emphasized that the trial is structured to generate the rigorous evidence necessary to determine the protective capabilities of the participating vaccines for at-risk individuals.