On Feb. 3, 2025, in a global first, Uganda’s Ministry of Health, the World Health Organization (WHO) and other partners announced they had launched a first ever vaccine trial for Ebola from the Sudan species of the virus, and at an unprecedented speed for a randomized vaccine trial in an emergency.

The principal investigators from Makerere University and the Uganda Virus Research Institute (UVRI), with support from WHO and other partners, have worked tirelessly to get the trial ready in 4 days since the outbreak was confirmed on 30 January. It is the first trial to assess the clinical efficacy of a vaccine against Ebola disease due to Sudan virus. The speed was achieved through advanced research preparedness, while ensuring full compliance with national and international regulatory and ethical requirements.

The candidate vaccine was donated by IAVI, with financial support from WHO, the Coalition for Epidemic Preparedness Innovations (CEPI), Canada’s International Development Research Centre (IDRC), and the European Commission’s Health Emergency Preparedness and Response Authority (HERA) and support from the Africa Centres for Disease Control and Prevention (Africa CDC).

Three vaccination rings were defined. The first ring involves about 40 contacts and contacts of contacts of the first reported and confirmed case, a health worker who has died.

Although several promising candidate medical countermeasures are progressing through clinical development, to date, there is no licensed vaccine available to effectively combat a potential future outbreak of Ebola disease from the Sudan species of the virus.

Licensed vaccines exist only for the disease caused by Ebola virus, formerly known as Zaïre ebolavirus. Likewise for treatments, approved treatments are only available for Ebola virus.