An Ebola vaccine known as VSV-EBOV, provided by Merck, Sharp & Dohme, has shown 100% efficacy in individuals, according to results from an interim analysis published (open access) today (July 31) in the British journal The Lancet.
“This is an extremely promising development,” said Margaret Chan, M.D., Director-General of the World Health Organization. “The credit goes to the Guinean Government, the people living in the communities and our partners in this project. An effective vaccine will be another very important tool for both current and future Ebola outbreaks.”
An independent body of international experts — the Data and Safety Monitoring Board — conducted the review.
Based on the results, the Guinean national regulatory authority and ethics review committee have approved continuation of the trial to acquire conclusive evidence for the vaccine’s capacity to protect populations through what is called “herd immunity.”
“The ‘ring’ vaccination method adopted for the vaccine trial is based on the smallpox eradication strategy,” said John-Arne Røttingen, Director of the Division of Infectious Disease Control at the Norwegian Institute of Public Health and Chair of the Study Steering Group.
“The premise is that by vaccinating all people who have come into contact with an infected person you create a protective ‘ring’ and stop the virus from spreading further. This strategy has helped us to follow the dispersed epidemic in Guinea, and will provide a way to continue this as a public health intervention in trial mode.”
“This record-breaking work marks a turning point in the history of health R&D,” said Assistant Director-General Marie-Paule Kieny, who leads the Ebola Research and Development effort at WHO. “We now know that the urgency of saving lives can accelerate R&D. We will harness this positive experience to develop a global R&D preparedness framework so that if another major disease outbreak ever happens again, for any disease, the world can act quickly and efficiently to develop and use medical tools and prevent a large-scale tragedy.”
VSV-EBOV was developed by the Public Health Agency of Canada.