NOVA SCOTIA, CANADA / RankWire.AI / – Moderna has initiated a Phase 1 trial of a vaccine targeting Bundibugyo ebolavirus amidst an escalating outbreak in the Democratic Republic of the Congo. On August 3, in Truro, Nova Scotia, a volunteer received the inaugural dose of the mRNA-1469 vaccine. This marks the vaccine’s debut in human testing. The World Health Organization has classified the Congolese outbreak as an international public health emergency.
Approximately 80 healthy adults will participate in the Phase 1 trial across three Canadian sites. The focus of the study is to evaluate the vaccine’s safety, tolerability, and capacity to elicit an immune response. Importantly, the trial is not designed to demonstrate the vaccine’s effectiveness in preventing Ebola infection. Early-stage research emphasizes safety and dosage determination prior to larger-scale studies. The Coalition for Epidemic Preparedness Innovations has pledged up to $50 million to fund testing, manufacturing efforts, and additional research doses.
WHO reported 3,605 confirmed cases and 1,587 deaths in DR Congo by July 30, with at least 651 recoveries. Updated data from August 4 indicated cases exceeding 3,800 and fatalities above 1,700. Health officials identified infections across 49 health zones spanning five provinces, with Ituri remaining the epicenter, accounting for about 88% of confirmed cases.
Outbreak underscores absence of approved vaccine
This epidemic involves Bundibugyo ebolavirus, which is one of multiple species within the Ebola virus family. Currently, no licensed vaccine or targeted treatment exists for this particular species. Existing authorized Ebola vaccines primarily target Zaire ebolavirus, which causes a different clinical form. Historically, Bundibugyo ebolavirus has caused outbreaks in Uganda and DR Congo, with the country experiencing 17 outbreaks since its initial identification in 1976.
The virus transmits through direct contact with infected blood, body fluids, organs, or contaminated materials. Public health teams have scaled up testing, contact tracing, treatment, and infection prevention measures across impacted regions. By July 30, authorities had listed 17,863 contacts for monitoring. WHO also documented 151 confirmed infections among healthcare workers, including 44 fatalities. Ongoing armed conflicts, population displacement, and attacks on healthcare facilities have complicated access to affected populations in multiple communities.
Other vaccine projects progress in parallel
This Moderna trial follows a separate Phase 1 study launched by the University of Oxford in the UK. The first dose of the Oxford candidate was administered on July 24. The Oxford vaccine employs the ChAdOx1 platform, whereas Moderna’s candidate utilizes messenger RNA technology. The Serum Institute of India produced the Oxford vaccine, creating a stockpile of approximately 620,000 doses and supplying 4,000 investigational doses for clinical testing.
Support from CEPI extends to both programs, as part of a broader initiative to develop vaccines against Bundibugyo Ebola. The organization also backs two other candidates based on recombinant vesicular stomatitis virus technology—one developed by IAVI with manufacturing led by Hilleman Laboratories and the other by Public Health Vaccines—none of which have received approval for public use. According to WHO, sustained efforts in surveillance, laboratory diagnosis, patient management, safe burial practices, and community engagement remain critical components of the outbreak response.