Following encouraging data from safety clinical trials in late 2014, the World Health Organization (WHO), alongside the Health Ministry of Guinea, Médecins Sans Frontières (MSF), Epicentre and the Norwegian Institute of Public Health, will lead a phase III study of the rVSV-ZEBOV (Merck) vaccine to see if it is able to prevent Ebola infection. A second vaccine will be tested in a sequential study, as supply becomes available.
The Guinea Ebola vaccine trial is the latest in a series of international commitments to fast-track the development of candidate Ebola vaccines. The Wellcome Trust provided £3 million to support the first clinical safety trial of rVSV-ZEBOV, and a further £2 million from the Trust and the UK Department for International Development (DFID) will help support the efficacy trials that will begin this weekend.
WHO Director-General, Margaret Chan, said: "We have worked hard to reach this point. There has been massive mobilisation on the part of the affected countries and all partners to accelerate the development and availability of proven interventions. If a vaccine is found effective, it will be the first preventive tool against Ebola in history."
Dr Jeremy Farrar, Director of the Wellcome Trust, said: "It’s fantastic to see large scale efficacy trials of this promising Ebola vaccine getting underway in Guinea. Testing investigational medicines during an epidemic is incredibly challenging, but this approach gives us the best possible chance of finding a safe and effective vaccine in time to save lives during the current epidemic, and to help us prepare for future outbreaks.
"Just getting to this point is a phenomenal achievement and one that would not have been possible without the hard work and unprecedented global collaboration between public and private entities, governments and the local communities in the three affected regions."
Vaccination will take place in areas of Basse Guinée, the region that currently has the highest number of cases in the country. The study design is a 'ring vaccination', which involves tracing the contacts of a newly diagnosed patient (the index case) and, with their consent, vaccinating them in a bid to prevent transmission. Vaccination will also be proposed to front-line workers in the area where the trial will take place. A similar approach was used to eradicate smallpox in the 1970s.
Dr Charlie Weller, Senior Portfolio Developer at the Wellcome Trust, added: "The objectives of the trial are two-fold: to see if the vaccine protects the contacts who were vaccinated, and if vaccinating these people will create a buffer – or 'ring' of protected individuals – around the index case, preventing further spread of the infection. This is a crucial step to finding a safe and effective vaccine for Ebola."
The trial is being funded by MSF, the Research Council of Norway, the Canadian government, WHO, DFID and the Wellcome Trust. The Trust has now committed more than £10 million as part of an emergency package of research funding to tackle the ongoing Ebola epidemic in West Africa.