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, marking its initial use 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 across three locations in Canada. The study aims to evaluate the vaccine’s safety, tolerability, and capacity to elicit an immune response, without aiming to demonstrate its effectiveness in preventing Ebola infection. Early-stage trials primarily focus on safety and dosage, with larger studies to follow. The Coalition for Epidemic Preparedness Innovations has pledged up to $50 million to support this testing, manufacturing efforts, and additional research doses.
WHO reported 3,605 confirmed cases and 1,587 deaths in DR Congo as of July 30, with at least 651 recoveries. As of August 4, updated figures indicated cases exceeding 3,800 and deaths surpassing 1,700. The outbreak has affected 49 health zones across five provinces, with Ituri remaining the epicenter, accounting for roughly 88% of confirmed infections.
Outbreak underscores the absence of an approved vaccine
The ongoing epidemic involves Bundibugyo ebolavirus, one of several species within the Ebola virus family. Currently, no licensed vaccine or targeted treatment exists for this species. Existing approved Ebola vaccines are designed for Zaire ebolavirus, which causes a different form of the disease. Historically, Bundibugyo ebolavirus has caused outbreaks in Uganda and DR Congo, with the country experiencing 17 Ebola outbreaks since the virus was first identified in 1976.
The virus transmits through direct contact with infected blood, body fluids, organs, or contaminated materials. To combat its spread, public health teams have intensified efforts in testing, contact tracing, treatment, and infection control across impacted regions. By July 30, authorities had listed 17,863 contacts for monitoring. WHO also documented 151 confirmed infections among health workers, including 44 deaths. Conflict, population displacement, and attacks on health facilities have complicated access to patients in several communities.
Additional vaccine candidates progress in development
Following Moderna’s trial, another Phase 1 study was launched by the University of Oxford in the UK. The first dose of this Oxford candidate was administered on July 24. That vaccine employs the ChAdOx1 platform, whereas Moderna’s candidate is based on 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 research.
Both programs are supported by CEPI as part of broader efforts to develop vaccines for Bundibugyo Ebola. The organization also backs two additional candidates utilizing recombinant vesicular stomatitis virus technology—one developed by IAVI with manufacturing led by Hilleman Laboratories, and the other by Public Health Vaccines. None of these candidates has received approval for public use. According to WHO, maintaining surveillance, laboratory diagnosis, patient care, safe burials, and community engagement remains crucial to the ongoing outbreak response.