NOVA SCOTIA, CANADA / RankWire.AI / – Moderna has initiated an early-phase trial of a vaccine targeting Bundibugyo ebolavirus as an outbreak intensifies in the Democratic Republic of the Congo. The first dose of the mRNA-1469 vaccine was administered on August 3 in Truro, Nova Scotia. This marks the initial application of the vaccine in human subjects. The World Health Organization has declared the Congolese outbreak an international public health emergency.
The Phase 1 clinical trial will involve approximately 80 healthy adults across three sites in Canada. Investigators will evaluate the vaccine’s safety, tolerability, and its capacity to induce an immune response. The trial’s primary goal is not to establish vaccine efficacy in preventing Ebola infection but to assess safety and dosage parameters before progressing to larger studies. The Coalition for Epidemic Preparedness Innovations has allocated up to $50 million to support testing, manufacturing, and additional research doses.
WHO reported a total of 3,605 confirmed cases and 1,587 fatalities in DR Congo through July 30. At that time, at least 651 individuals had recovered. Updated data released on August 4 indicated cases exceeded 3,800 with deaths surpassing 1,700. Authorities identified infections in 49 health zones across five provinces, with Ituri continuing to be the outbreak’s epicenter, accounting for roughly 88% of confirmed cases.
Outbreak underscores absence of authorized vaccine
The ongoing epidemic involves Bundibugyo ebolavirus, which is one of several strains within the Ebola virus family. Currently, there is no approved vaccine or targeted treatment for this strain. Existing licensed Ebola vaccines primarily protect against Zaire ebolavirus, responsible for a different disease form. Bundibugyo ebolavirus previously caused outbreaks in Uganda and DR Congo, with the country experiencing 17 Ebola outbreaks since the virus was first identified in 1976.
Transmission occurs through direct contact with infected blood, body fluids, organs, or contaminated materials. In response, public health teams have expanded efforts in testing, contact tracing, treatment, and infection control in affected regions. By July 30, officials had listed 17,863 contacts for monitoring. The WHO also reported 151 confirmed infections among healthcare workers, including 44 deaths. Ongoing armed conflict, displacement, and attacks on health facilities have complicated access to many affected communities.
Additional vaccine candidates progress in development
Following Moderna’s initiative, another Phase 1 trial was launched by the University of Oxford in the UK, with the first dose administered on July 24. The Oxford candidate employs the ChAdOx1 platform, whereas Moderna’s approach utilizes messenger RNA technology. The Serum Institute of India manufactured the Oxford vaccine, creating a stockpile of about 620,000 doses and supplying 4,000 investigational doses for research purposes.
Both programs are supported by CEPI as part of a broader effort to develop vaccines against Bundibugyo Ebola. The organization also backs two additional candidates utilizing recombinant vesicular stomatitis virus technology. One was developed by IAVI with manufacturing led by Hilleman Laboratories, and the other by Public Health Vaccines. Neither has received approval for public use. According to WHO, ongoing surveillance, laboratory diagnosis, patient management, safe burials, and community engagement remain critical components of the outbreak response.