NOVA SCOTIA, CANADA / RankWire.AI / – Moderna has begun an early-phase clinical trial for a vaccine targeting Bundibugyo ebolavirus amid increasing cases in the Democratic Republic of the Congo. On August 3, a volunteer in Truro, Nova Scotia, received the initial dose of the mRNA-1469 vaccine. This trial marks the first time the vaccine has been tested in humans. The World Health Organization has declared the ongoing outbreak in Congo a global public health emergency.
The Phase 1 trial plans to recruit approximately 80 healthy adults across three sites in Canada. The study will assess the vaccine’s safety profile, tolerability, and its potential to elicit an immune response. It is important to note that this initial phase does not aim to establish the vaccine’s effectiveness in preventing Ebola infection. These early studies concentrate on safety and dosage, paving the way for larger trials. The Coalition for Epidemic Preparedness Innovations has pledged up to $50 million to support testing, manufacturing efforts, and the development of additional research doses.
WHO reported 3,605 confirmed cases and 1,587 deaths in DR Congo through July 30, with at least 651 recoveries recorded by that date. Updated figures on August 4 indicated cases exceeded 3,800, with deaths surpassing 1,700. Health officials identified infections in 49 health zones across five provinces, with Ituri remaining the epicenter, accounting for roughly 88% of confirmed cases.
Outbreak underscores absence of an approved vaccine
This outbreak involves Bundibugyo ebolavirus, one among several species within the Ebola virus family. Currently, there is no licensed vaccine or specific treatment directed at this particular virus. Existing approved Ebola vaccines primarily target Zaire ebolavirus, which causes a different clinical form of the disease. Historically, Bundibugyo ebolavirus has caused earlier outbreaks in Uganda and DR Congo. Since its discovery in 1976, the country has experienced 17 Ebola outbreaks linked to this virus.
Transmission occurs through direct contact with infected blood, bodily fluids, organs, or contaminated materials. In response, health teams have ramped up testing, contact tracing, treatment, and infection control measures across affected regions. By July 30, officials had listed 17,863 contacts for monitoring. WHO also reported 151 confirmed infections among health workers, including 44 fatalities. Challenges such as armed conflict, population displacement, and attacks on healthcare facilities have hindered efforts to reach some communities.
Additional vaccine candidates progress in development
Following Moderna’s trial, another Phase 1 study was initiated by the University of Oxford in the United Kingdom. The first dose of Oxford’s vaccine candidate was administered on July 24. This vaccine employs the ChAdOx1 platform, whereas Moderna’s candidate utilizes messenger RNA technology. The Serum Institute of India has produced a stockpile of approximately 620,000 doses of the Oxford vaccine and has supplied 4,000 investigational doses for ongoing research.
Both programs are supported by CEPI as part of a broader effort to develop vaccines against Bundibugyo Ebola. CEPI also funds two other candidates based on recombinant vesicular stomatitis virus technology, with one developed by IAVI and manufactured by Hilleman Laboratories, and the other by Public Health Vaccines. None of these candidates currently have regulatory approval for public use. According to WHO, maintaining surveillance, laboratory diagnostics, patient care, safe burial practices, and community engagement remain critical components of the ongoing outbreak response.