The World Health Organization (WHO), in partnership with Uganda’s Ministry of Health and global health partners, has initiated the first-ever clinical trial for a vaccine targeting the Sudan species of the Ebola virus.
This groundbreaking trial seeks to evaluate the vaccine’s effectiveness against the deadly virus, marking a significant step forward in global pandemic preparedness.
Researchers from Makerere University and the Uganda Virus Research Institute (UVRI), supported by WHO and other partners, prepared the trial in just four days following the outbreak’s confirmation on January 30. This is the first clinical trial to assess the efficacy of a vaccine specifically against the Sudan strain of the Ebola virus.
The rapid launch was made possible through advanced research preparedness while ensuring full compliance with national and international regulatory and ethical standards.
The candidate vaccine was donated by IAVI, with financial backing 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), alongside additional support from the Africa Centres for Disease Control and Prevention (Africa CDC).
“This is a critical milestone for pandemic preparedness and saving lives when outbreaks occur,” said Dr. Tedros Adhanom Ghebreyesus, WHO’s Director-General. “This achievement is a testament to the dedication of Uganda’s health workers, community involvement, and the commitment of the Ministry of Health, Makerere University, and UVRI. WHO’s research efforts, involving hundreds of scientists through our Filoviruses network, have also been instrumental. We deeply appreciate our partners—from IAVI for donating the vaccine to CEPI, EU HERA, and Canada’s IDRC for funding, and Africa CDC for additional support. None of this would have been possible without their collaboration.”
During Uganda’s 2022 outbreak of Ebola caused by the Sudan virus species, researchers developed a randomized protocol for testing candidate vaccines.
Under the Minister of Health’s leadership, principal investigators were appointed, and teams were trained to conduct vaccine trials during an active outbreak.
Today, Uganda’s Minister of Health officially launched a randomized trial for the recombinant vesicular stomatitis virus (rVSV) candidate vaccine in Kampala, with WHO co-sponsoring the initiative.
WHO representatives at the event included Dr. Mike Ryan, Executive Director of the Health Emergencies Programme and Deputy Director-General, along with Dr. Kasonde Mwinga, WHO’s representative to Uganda, and other colleagues.
As part of the trial, three vaccination rings were established. The first ring includes approximately 40 individuals who had direct or secondary contact with the first confirmed case—a health worker who has since passed away.
Despite progress in developing medical countermeasures, no licensed vaccine currently exists for Ebola outbreaks caused by the Sudan virus species. At present, approved vaccines and treatments are available only for the Ebola virus (formerly Zaire ebolavirus).
The WHO independent candidate vaccine prioritization working group recommended the vaccine used in this trial. If successful, it could help control the outbreak and provide critical data for eventual vaccine approval.
In preparation, research teams underwent training in good clinical practice (GCP) and standard operating procedures in 2022. They recently completed refresher courses ahead of the trial. Over the weekend, WHO experts in clinical trials and ring vaccination arrived in Uganda to support implementation and ensure GCP compliance.
Vaccine doses had already been pre-positioned in the country. WHO collaborated with principal investigators, national authorities, and the vaccine developer to verify cold chain documentation and confirm proper storage over time.
Additionally, under an agreement with Uganda’s Ministry of Health, WHO has secured a commitment from IAVI to supply more doses of the candidate vaccine soon.
