A new vaccine targeting the strain of Ebola virus responsible for the deaths of hundreds of people in the Democratic Republic of Congo this year has begun human clinical trials in the UK
The experimental vaccine developed by researchers at the University of Oxford has entered human trials, with researchers hoping it could work against the Bundibugyo strain of Ebola virus currently on the rise across the African nation.
The vaccine is called ChAdOx BDBV
The trial, led by scientists from the Oxford Vaccine Group and the Institute of Pandemic Sciences, will assess whether the vaccine is safe and how strongly it stimulates the immune system. The study will enroll 50 healthy adult volunteers and represents the first clinical evaluation of a vaccine developed specifically against the Bundibugyo Ebola virus.
The rapid progress of the vaccine into human trials reflects lessons learned from the COVID-19 pandemic, where adaptive vaccine technologies allowed researchers to respond quickly to emerging infectious threats. ChAdOx BDBV uses the Oxford chimpanzee adenovirus vector platform, the same technology used to develop the Oxford-AstraZeneca COVID-19 vaccine.
The urgency behind the program stems from a significant gap in Ebola preparedness. Although there is already a vaccine for Ebola, it does not protect against all Ebola viruses.
The only licensed Ebola vaccine currently available, Ervebo (rVSV-ZEBOV)developed to protect against Zaire Ebolathe strain responsible for the devastating 2014–2016 West African Ebola outbreak that caused more than 11,000 deaths. The vaccine has been highly effective in preventing disease caused by the Zaire Ebola virus and has become an important tool during outbreaks through ring vaccination strategies, where people exposed to the virus and their contacts are vaccinated.
However, Ebola is not a single virus. The disease is caused by several different types of viruses within the Ebola family, including Zaire Ebola, Sudan Ebola, and Bundibugyo Ebola. These viruses differ genetically, meaning that immunity built up against one species does not necessarily provide protection against another.
As a result, Ervebo is not licensed for Ebola Bundibugyo and is not expected to provide adequate protection against the strain currently circulating in the DRC.
This has left public health teams responding to the outbreak without access to an approved vaccine specifically matched to the virus that causes infections. Instead, control of the outbreak relied on rapid diagnosis, contact tracing, infection prevention measures, supportive care, and the development of new medical countermeasures.
Oxford’s vaccine program is one part of a broader effort to address this vulnerability. The researchers hope that if the Phase I trial proves the vaccine is safe and produces a strong immune response, further studies could assess its ability to protect people during future outbreaks.
Early-stage vaccine trials are primarily designed to document safety and measure immune responses rather than demonstrate efficacy. However, the start of this first human trial represents a major milestone in expanding Ebola vaccine readiness beyond a single strain of the virus.
The ongoing outbreak of the Bundibugyo Ebola virus has highlighted a long-standing challenge in infectious disease preparedness: vaccines developed against a variant pathogen may not protect against closely related viruses that emerge later. Creating a broader vaccine portfolio could help ensure that future Ebola outbreaks can be addressed with faster and more targeted responses.
An effective vaccine has been approved for the Zaire strain of Ebola virus, but it is ineffective against Bundibugyo and other strains of Ebola
THE current outbreak has already claimed more than 800 lives and sickened more than 2,000 people according to the latest World Health Organization statistics updated in mid-July.
