Faced with the progression of the Ebola epidemic in the Democratic Republic of Congo (DRC), laboratories are mobilizing to try to develop a vaccine against the Bundibugyo strain, a rare variant of the virus for which no approved vaccine yet exists.
In the United Kingdom, the scientific team at Oxford University that participated in the development of the Oxford-AstraZeneca vaccine against Covid-19 quickly redirected its research to design a vaccine candidate specific to this strain.
“We were able to quickly reorient ourselves and begin developing a vaccine against the Bundibugyo virus,” explains Professor Teresa Lambe, a specialist in vaccine immunology at the Pandemic Sciences Institute in Oxford. “The experience gained during previous Ebola outbreaks allowed us to act much faster.”
The researchers are drawing in particular on lessons learned from the major Ebola epidemic of 2013 to 2016 in West Africa, which caused more than 11,000 deaths. Teresa Lambe participated in clinical trials of several experimental vaccines at that time.
The scientist insists, however, that no shortcuts will be taken regarding safety. Even if accelerated, the development of a vaccine requires essential preclinical and clinical trial phases.
“We are trying to carry out several steps in parallel in order to save time, as was done during the Covid-19 pandemic,” she emphasizes. “But we will only know if these vaccines are effective in a real epidemic situation.”
According to experts, the vaccine candidates currently being developed will therefore not be ready quickly enough to respond to the current health emergency in the DRC.
Meanwhile, health authorities are focusing their efforts on contact tracing and isolating suspected cases, considered the most effective tools to contain the spread of the virus.
“Contact tracing and isolating cases are absolutely essential,” Teresa Lambe emphasizes. “We must quickly identify all potential cases if we hope to control the epidemic.”
The situation is all the more worrying as the health response is hampered by significant security tensions in eastern Congo. Several healthcare centers have been attacked, while facilities housing suspected patients have been set on fire by residents angered by or distrustful of medical teams.
The Ebola virus is transmitted through contact with the bodily fluids of infected or deceased individuals. Traditional funeral rites are therefore a major source of contamination, fueling tensions when authorities impose strictly controlled burials.
Experts estimate that the Bundibugyo strain has a mortality rate of between 30 and 50%, lower than that observed in some previous Ebola epidemics, but still extremely high.
“This remains a particularly serious disease,” warns Teresa Lambe. “Even if this strain appears less deadly than other variants of the Ebola virus, it remains a major health threat.”
