Final trial results confirm Ebola vaccine provides high protection against disease
An experimental Ebola vaccine has proved to be highly protective against the deadly virus in a major trial in Guinea.
The WHO citing results published today in The Lancet, said the findings add weight to early trial results published last year.
The trial led by WHO, together with Guinea’s Ministry of Health, Medecins sans Frontieres and the Norwegian Institute of Public Health, in collaboration with other international partners
The statement from WHO said “the vaccine, called rVSV-ZEBOV, was studied in a trial involving 11 841 people in Guinea during 2015”, adding that “among the 5837 people who received the vaccine, no Ebola cases were recorded 10 days or more after vaccination while in comparison, there were 23 cases 10 days or more after vaccination among those who did not receive the vaccine.”
The statement quotes Dr Marie-Paule Kieny, WHO’s Assistant Director-General for Health Systems and Innovation, and the study’s lead author as saying that “while these compelling results come too late for those who lost their lives during West Africa’s Ebola epidemic, they show that when the next Ebola outbreak hits, we will not be defenceless”.
“Ebola left a devastating legacy in our country. We are proud that we have been able to contribute to developing a vaccine that will prevent other nations from enduring what we endured,” said Dr KeÏta Sakoba, Coordinator of the Ebola Response and Director of the National Agency for Health Security in Guinea.
According to WHO, The trial took place in the coastal region of Basse-Guinée, the area of Guinea still experiencing new Ebola cases when the trial started in 2015. The trial used an innovative design, a so-called “ring vaccination” approach – the same method used to eradicate small pox.
In addition to showing high efficacy among those vaccinated, the trial also shows that unvaccinated people in the rings were indirectly protected from Ebola virus through the ring vaccination approach (so called “herd immunity”). However, the authors note that the trial was not designed to measure this effect, so more research will be needed.
Since Ebola virus was first identified in 1976, sporadic outbreaks have been reported in Africa. But the 2013–2016 West African Ebola outbreak, which resulted in more than 11 300 deaths, highlighted the need for a vaccine.
The rVSV-ZEBOV trial is funded by WHO, with support from the Wellcome Trust; the United Kingdom Department for International Development; the Norwegian Ministry of Foreign Affairs; the Norwegian Institute of Public Health through the Research Council of Norway,; the Canadian Government through the Public Health Agency of Canada, Canadian Institutes of Health Research, the International Development Research Centre, and the Department of Foreign Affairs, Trade and Development; and Médecins Sans Frontières.