NOVA SCOTIA, CANADA / RankWire.AI / – Moderna has initiated a preliminary trial of a vaccine targeting Bundibugyo ebolavirus as outbreaks expand in the Democratic Republic of the Congo. The first dose of the mRNA-1469 vaccine was administered to a volunteer on August 3 in Truro, Nova Scotia. This trial represents the vaccine’s initial application in humans. The World Health Organization has declared the Congolese outbreak an international public health emergency.
Approximately 80 healthy adults will participate in the Phase 1 trial at three sites across Canada. The research aims to evaluate the safety, tolerability, and capacity of the vaccine to elicit an immune response. The study does not intend to demonstrate the vaccine’s effectiveness in preventing Ebola infection. As an early-stage investigation, the focus remains on safety and dosage, with larger trials planned later. The Coalition for Epidemic Preparedness Innovations has pledged up to $50 million to support testing, manufacturing, and additional research doses.
WHO reported 3,605 confirmed cases and 1,587 deaths in DR Congo through July 30, with at least 651 recoveries. Updated figures from August 4 indicate cases exceeding 3,800 and deaths surpassing 1,700. The health authorities have identified infections across 49 health zones in five provinces. Ituri remains the outbreak’s epicenter, accounting for approximately 88% of confirmed cases.
Outbreak underscores absence of approved vaccine
The ongoing epidemic involves Bundibugyo ebolavirus, one of several species within the Ebola virus family. Currently, no approved vaccine or targeted treatment exists for this species. Most licensed Ebola vaccines are designed to combat Zaire ebolavirus, which causes a different form of the disease. Historically, Bundibugyo ebolavirus has caused previous outbreaks in Uganda and DR Congo. Since its discovery in 1976, the virus has been responsible for 17 Ebola outbreaks in the region.
Transmission occurs through direct contact with infected blood, body fluids, organs, or contaminated materials. Efforts by public health teams have included expanding testing, contact tracing, treatment, and infection control measures across affected zones. By July 30, authorities had listed 17,863 contacts for monitoring. WHO also documented 151 confirmed infections among health workers, including 44 fatalities. Ongoing conflict, population displacement, and attacks on health facilities have hindered access to many communities.
Progress of other vaccine candidates
The Moderna study follows another Phase 1 trial conducted by the University of Oxford in the UK, which began with the first dose on July 24. This vaccine employs the ChAdOx1 platform, contrasting with Moderna’s messenger RNA technology. The Serum Institute of India manufactured the Oxford candidate, creating a stockpile of approximately 620,000 doses, and supplied 4,000 investigational doses for clinical research.
Both efforts are supported by CEPI, part of a broader initiative to develop vaccines for Bundibugyo Ebola. The organization also funds two other candidates based on recombinant vesicular stomatitis virus technology. One, developed by IAVI, is being manufactured by Hilleman Laboratories, while the other is produced by Public Health Vaccines. Neither has received approval for public use. WHO emphasizes that surveillance, laboratory diagnostics, patient management, safe burials, and community engagement are critical components of the outbreak response.