WHO: Ebola Vaccine Highly Effective
WHO's announcement said while the vaccine has shown 100 percent efficacy in individuals, "more conclusive evidence is needed on its capacity to protect populations through what is called 'herd immunity.' To that end, the Guinean national regulatory authority and ethics review committee have approved continuation of the trial."
Saying that the world is "on the verge of an effective Ebola vaccine," the World Health Organization announced July 31 that results from an interim analysis of the Guinea Phase III efficacy vaccine trial show that VSV-EBOV (Merck, Sharp & Dohme) is highly effective against the disease. An independent body of international experts, the Data and Safety Monitoring Board, conducted the review and recommended that the trial continue. Preliminary results from analyses of the interim data have been published July 31 in the British journal The Lancet.
"This is an extremely promising development," said Dr. Margaret Chan, director-general of WHO. "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."
WHO's announcement said while the vaccine has shown 100 percent efficacy in individuals, "more conclusive evidence is needed on its capacity to protect populations through what is called 'herd immunity.' To that end, the Guinean national regulatory authority and ethics review committee have approved continuation of the trial."
"This is Guinea's gift to West Africa and the world," said Dr. Sakoba Keita, Guinea's national coordinator for the Ebola response. "The thousands of volunteers from Conakry and other areas of Lower Guinea, but also the many Guinean doctors, data managers, and community mobilizers, have contributed to finding a line of defence against a terrible disease."
"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."
The Guinea vaccination trial began March 23 in affected communities; since then, more than 4,000 close contacts of almost 100 Ebola patients, including family members, neighbours, and co-workers, have voluntarily participated in the trial, which is being implemented by the Guinean authorities, WHO, Médecins sans Frontières, and the Norwegian Institute of Public Health, with support from a broad partnership of international and national organizations.