Scientists at Oxford University are developing a vaccine targeting the Bundibugyo species of Ebola virus, with clinical trials potentially starting within two to three months. This development is significant as the Bundibugyo strain, responsible for a current outbreak in the Democratic Republic of Congo (DRC), has no proven vaccine and kills about one-third of those infected.
Why this matters
The ongoing Ebola outbreak in the DRC has resulted in approximately 750 suspected cases and 177 deaths. The World Health Organization (WHO) has raised the risk level in the DRC from “high” to “very high” and declared the outbreak a public health emergency of international concern. The Bundibugyo species is rare and has caused only two previous outbreaks, making vaccine development urgent to prevent further spread and fatalities.
Key developments in vaccine research
- The Oxford team is using the ChAdOx1 technology platform, which was also used to develop a Covid-19 vaccine. This platform is adaptable and can be quickly modified to target different viruses.
- The vaccine incorporates genetic material from the Bundibugyo Ebola virus into a genetically engineered chimpanzee cold virus, which safely delivers the genetic code to human cells to stimulate an immune response.
- The vaccine does not cause Ebola infection or symptoms but trains the immune system to recognize and fight the virus.
- Animal testing is currently underway at Oxford to evaluate the vaccine’s effectiveness before human trials can begin.
- The Serum Institute of India is prepared to mass-produce the vaccine once medical-grade material is available from Oxford.
- Another experimental Bundibugyo vaccine is also in development but is expected to take six to nine months before it can be tested in humans.
Background on the Bundibugyo Ebola outbreak
Bundibugyo Ebola is one of six known Ebola virus species, but only three species typically cause large outbreaks. Bundibugyo has caused only two previous outbreaks—in Uganda in 2007 and the DRC in 2012—and has not been detected for over a decade until the current outbreak.
Unlike the more common Zaire species of Ebola, for which a vaccine exists, there is no proven vaccine for Bundibugyo. The current outbreak’s severity and rarity make the development of a targeted vaccine a priority for global health authorities.
Vaccine use and public health strategy
Ebola vaccines are not intended for mass vaccination campaigns like those used during the Covid-19 pandemic. Instead, they are deployed using a ring vaccination strategy. This approach immunizes people most likely to be exposed to the virus, such as close contacts of confirmed cases and healthcare workers treating infected patients.
Oxford’s vaccine development builds on previous work on vaccines for the Sudan species of Ebola and the Marburg virus, both related hemorrhagic viruses.
Outlook and next steps
The WHO has emphasized that while the vaccine could be ready for clinical trials in two to three months, its effectiveness remains uncertain until animal and human trials are completed. The Oxford team is working urgently to prepare for the possibility that the outbreak could worsen and require vaccination as part of the response.
Prof Lambe, head of vaccine immunology at Oxford, noted the importance of speed and preparedness, stating that while containment measures like contact tracing and quarantine are hoped to be sufficient, vaccine development must continue without delay.
Recommended reading
For more context, see related Peack News coverage and explainers linked below.
