NOVA SCOTIA, CANADA / RankWire.AI / – Moderna has begun early-stage testing of a vaccine targeting Bundibugyo ebolavirus as an outbreak expands within the Democratic Republic of the Congo. The initial dose of the mRNA-1469 vaccine was administered on August 3 in Truro, Nova Scotia. This trial represents the first time the vaccine is tested in humans. The World Health Organization has declared the outbreak in Congo an international public health emergency.
The Phase 1 trial plans to recruit approximately 80 healthy adults across three sites in Canada. The main goals are to evaluate the safety, tolerability, and immune response elicited by the vaccine. It is not designed to determine whether the vaccine prevents Ebola infection. Early-stage trials focus on assessing safety and dosage levels before progressing to larger-scale studies. The Coalition for Epidemic Preparedness Innovations has committed up to $50 million to fund testing, manufacturing, and further research doses.
WHO reported 3,605 confirmed cases and 1,587 deaths in DR Congo through July 30. By that date, at least 651 patients had recovered. Updated data released on August 4 showed cases exceeding 3,800 and deaths surpassing 1,700. Health officials identified infections across 49 health zones in five provinces, with Ituri remaining the epicenter accounting for roughly 88% of confirmed cases.
Outbreak underscores absence of an approved vaccine
The ongoing epidemic involves Bundibugyo ebolavirus, which is one of several strains within the Ebola virus family. Currently, there is no licensed vaccine or targeted treatment for this particular strain. Existing approved Ebola vaccines are directed at Zaire ebolavirus, which causes a different form of the disease. Historically, Bundibugyo ebolavirus has caused previous outbreaks in Uganda and DR Congo. Since its identification in 1976, researchers have documented 17 Ebola outbreaks involving this strain.
Transmission occurs primarily through direct contact with infected blood, bodily fluids, organs, or contaminated materials. Public health teams are intensifying efforts around testing, contact tracing, treatment, and infection prevention in affected regions. As of July 30, officials had identified and monitored 17,863 contacts. WHO also reported 151 confirmed infections among healthcare workers, including 44 fatalities. Ongoing armed conflict, displacement, and assaults on health facilities have hindered access to patients in several communities.
Additional vaccine candidates make progress
Following Moderna’s trial, another Phase 1 study was launched by the University of Oxford in the UK. The first dose of the Oxford-developed vaccine was administered on July 24. This vaccine employs the ChAdOx1 platform, whereas Moderna’s candidate is based on messenger RNA technology. The Serum Institute of India produced the Oxford vaccine and assembled a stockpile of approximately 620,000 doses, including 4,000 investigational doses allocated for clinical trials.
Both programs are supported by CEPI as part of a broader effort 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 another by Public Health Vaccines. Neither has received approval for public distribution. The WHO emphasizes that surveillance, laboratory diagnosis, patient care, safe burials, and community engagement remain crucial components of the outbreak response.