A new vaccine designed to combat the Ebola virus has received regulatory approval in the UK to begin human clinical trials. This milestone comes just eight weeks after a public health emergency was declared on 17 May. The vaccine, developed by scientists at the University of Oxford, is the first of four currently in development to reach the clinical trial stage.
Recruitment for volunteers is underway, with the first doses expected to be administered to healthy adults in the UK within the coming weeks.
The ongoing Ebola epidemic, which is centered in the Democratic Republic of the Congo, has resulted in 625 deaths and 1,792 laboratory-confirmed cases. The outbreak is caused by the Bundibugyo species of Ebola, a variant that has caused two previous outbreaks.
Because the six known species of Ebola are described by scientists as "sisters rather than twins," they require distinct treatments and vaccines, meaning there are currently no approved drugs or vaccines for this specific strain.
The situation remains critical as the outbreak persists within a conflict zone characterized by highly mobile populations, further emphasizing the urgent need for a preventative solution.
Dr. Katrina Pollock, the chief investigator for the trial at the University of Oxford, explained that the team conducts early-stage phase one trials routinely to ensure they are prepared for such emergencies. The upcoming trial will involve 50 healthy adult volunteers aged 18 to 55.
While these participants will be monitored for a year, researchers expect to determine quickly whether the vaccine successfully triggers the desired immune response or causes any unexpected side effects.
The Oxford team is also working alongside partners in Uganda to prepare for potential trials in Africa.
The development of this vaccine was accelerated by utilizing the same technology that gained prominence during the Covid-19 pandemic, specifically the platform used for the Oxford/AstraZeneca Covid vaccine. The technology employs a common cold virus that infects chimpanzees, which has been genetically modified to be safe.
This virus acts as an envelope to deliver a snippet of genetic code from the Bundibugyo species of Ebola into the body.
This process does not cause an infection, but it prompts the body to produce a single viral protein from the Ebola virus, which is sufficient to alert the immune system and initiate a protective response.
The vaccine has already been tested on mice and macaque monkeys, and the Serum Institute of India has manufactured approximately 620,000 doses to a clinical standard. Vaccine researcher Alex Sampson noted that the team was able to scale up production rapidly upon hearing of the outbreak.
While vaccine development typically spans a decade, Sampson emphasized that no safety corners were cut; instead, the team performed all standard tests in parallel, requiring multiple teams to work around the clock in various locations.
Addressing safety concerns, Dr. Pollock acknowledged that the technology used in the Covid-19 vaccine was previously restricted in some countries due to rare blood clots affecting up to one in 100,000 people. She noted that while it is possible this vaccine carries a similar risk, it remains significantly lower than the threat posed by the Bundibugyo species, which kills approximately one-third of those infected.
Dr. Pollock stressed that severe side effects are very rare and that the team has carefully considered the implications for healthy volunteers, ensuring all potential risks are communicated. She also highlighted that the Covid-19 AstraZeneca vaccine was administered safely to millions of people.
In addition to the Oxford project, three other vaccines are currently in development for the Bundibugyo species. These include a candidate from the biotechnology firm Moderna, which is utilizing mRNA technology, and efforts by the International Aids Vaccine Initiative and Public Health Vaccines in the US, which are employing a technique proven effective for another species of Ebola, though it is noted to be slower to manufacture.
That means the body should already have a head start if it encounters Ebolavirus for real.
Based on that data, the UK's Medicines and Healthcare Products Regulatory Agency has given the go-ahead for human trials.
