The World Health Organization has announced the launch of the first clinical trial for an Ebola vaccine in the ongoing outbreak centered in the Democratic Republic of Congo. WHO Director-General Tedros Adhanom Ghebreyesus stated in a social media post on Friday that the initial participants received the Ervebo vaccine in Bunia, the capital of the northeastern Ituri province, which serves as the epicentre of the epidemic.
Ervebo, a vaccine previously approved to combat the more common Zaire strain of Ebola, is being evaluated in a full-scale human trial to determine whether it provides cross-protection against the Bundibugyo species driving the current epidemic. The WHO chief noted that the organization is supporting the DRC-led initiative to evaluate potential countermeasures and protect populations at risk.
The Democratic Republic of Congo declared its 17th and most severe Ebola outbreak in May. Since then, health authorities have documented more than 9,700 cases, with fatalities surpassing 4,600. In response to the escalating crisis, the WHO declared a public health emergency of international concern, representing its second-highest alert level. The outbreak has since expanded across four countries in eastern, central, and western Africa, marking the widest geographic dissemination of any recorded Ebola epidemic on the continent.
The evaluation is operating under the Tumaini trial framework, a single-trial structure capable of assessing the safety, efficacy, and immunogenicity of multiple vaccine products simultaneously. Researchers will employ a ring vaccination strategy, focusing immunization efforts on individuals identified as being at high risk of infection through contact tracing.
In addition to Ervebo, the trial is designed to incorporate two candidate vaccines specifically targeted against the Bundibugyo virus, both of which are currently progressing through earlier-stage clinical evaluations. One candidate is a ChAdOx1 adenoviral vector jab developed by the University of Oxford, while the second is an mRNA-based vaccine developed by the United States-based Moderna group. Both candidates have received financial backing from the Coalition for Epidemic Preparedness Innovations and are anticipated to join the trial shortly.
Significantly, the clinical trial protocol will include pregnant women and children aged 12 years and older, populations frequently omitted from standard clinical research studies. WHO Emergencies Director Chikwe Ihekweazu emphasized that the trial was structured specifically to generate the rigorous scientific evidence required to establish whether the evaluated vaccines can effectively protect vulnerable individuals.
