Scientists at Oxford University are racing to develop an experimental Ebola vaccine that could enter clinical trials within two to three months as concerns grow over the worsening outbreak in the Democratic Republic of Congo.
The outbreak, linked to the rare Bundibugyo strain of Ebola, has already recorded about 750 suspected cases and 177 deaths.
Unlike the more common Zaire strain, which already has an approved vaccine, Bundibugyo has no proven vaccine despite killing roughly one in three infected persons.
Researchers caution that there is no certainty the vaccine will work, as it must still undergo animal studies and human trials before its effectiveness can be confirmed. Still, the team says preparations are moving at speed in case the outbreak escalates further.
The World Health Organisation recently raised the risk level of the outbreak in the Democratic Republic of Congo from “high” to “very high,” while maintaining that the global threat remains low. The agency had earlier declared the situation a public health emergency of international concern, stressing that it does not amount to a pandemic.
The Oxford vaccine uses the same adaptable ChAdOx1 technology that helped produce the Oxford-AstraZeneca COVID-19 vaccine during the pandemic.
Scientists modified a harmless chimpanzee cold virus to carry genetic material from the Bundibugyo Ebola strain, enabling the body to recognise and fight the virus without causing infection or Ebola symptoms.
Researchers say the technology allows vaccines to be adjusted quickly to target emerging diseases.
Animal testing is already underway in Oxford, while India’s Serum Institute has been lined up to mass-produce the vaccine if the project advances successfully.
Professor Teresa Lambe, Calleva Head of Vaccine Immunology at the Oxford Vaccine Group, said speed remains critical.
“Once we get starting material to them they can go fast and they can go big,” she said.
Lambe noted that the vaccine may be available for early clinical trials within two to three months, although uncertainties remain.
“People are worried about this outbreak. Generally, you prepare for the worst-case scenario. Hopefully contact tracing and quarantine are all that’s needed, but we can’t take our foot off the gas,” she added.
The WHO said there is currently no animal data proving the vaccine’s effectiveness, meaning further testing will determine whether it becomes a promising candidate.
Another experimental vaccine for the Bundibugyo strain is also being developed elsewhere but is not expected to be ready for testing for another six to nine months.
Bundibugyo Ebola remains one of the least understood forms of the virus. Since Ebola was first identified in 1976, only two previous Bundibugyo outbreaks have been documented — in Uganda in 2007 and DR Congo in 2012.
Health experts say that if approved, the vaccine would likely be deployed using “ring vaccination,” where only close contacts of infected persons and frontline health workers are immunised rather than mass vaccination campaigns.
The Oxford team had already been developing similar vaccines for the Sudan strain of Ebola and the Marburg virus before the current outbreak intensified.
