The results of a clinical trial confirm that a Canadian vaccine against Ebola virus is highly efficient, marking an important step towards preventing deadly epidemics such as this one in West Africa.
Scientists have long failed to develop a vaccine against Ebola, encountering the sporadic nature of its outbreaks, as well as underfunding their research.
It is the first ever vaccine that has been shown to be effective. The scientific community had redoubled efforts in this direction after a serious outbreak of the epidemic in 2013, first in Guinea, then in Liberia and Sierra Leone, with 11,300 deaths.
The World Health Organization (WHO) has conducted a study of this vaccine, developed by the National Microbiology Laboratory of Canada – under the authority of the Public Health Agency of Canada – and licensed by The American company Merck & Co.
The conclusive results of the most recent clinical trial were revealed on Thursday in the British magazine The Lancet. Merck should seek regulatory approval in Europe and the United States in the coming year.
The experimental vaccine was administered to nearly 5,800 Guineans last year, while the Ebola virus was declining in the region. Subjects were vaccinated immediately after contact with an affected person or three weeks later. Within ten days, those who received the vaccine without delay had not contracted the virus. Of the guinea-pigs vaccinated three weeks later, 23 subjects were contaminated with Ebola.
The results published on Thursday confirm those of the preliminary study conducted a year earlier. Its findings had been so convincing that the clinical trial had been interrupted to allow all Guineans considered to be at risk to be immunized immediately.
“I really believe we have now a tool that will allow us to control a new outbreak of Ebola of Zaire strain,” said WHO Deputy General Director and co-author of the study, Dr. Marie-Paule Kieny.
She points out that other vaccines are being evaluated and this vaccine, although promising, is not effective against the Sudan strain of the virus.
Ebola was discovered in 1976 in former Zaire (the present Democratic Republic of Congo), but none of its outbreaks had been as devastating as those in West Africa.
Mamadou Dian Donghol Diallo.