Ebola: a predetermined ending?

1Being infected with the Ebola virus is a death sentence in 80% of cases. This surprisingly stable figure led teams from the Pasteur Institute and IRD, in conjunction with their partners, to look into the action mechanisms of the virus in the human body. In 1997, they started collecting blood from people affected by the Ebola virus to study the immune responses involved during the infection.

Handling the Ebola virus, Gabon.

2They detected a difference in immune responses between the survivors and the deceased, who died after an “inflammatory storm”. The initial immune response against the virus, which is non-specific, is so strong that it causes irreversible damage in the body, resulting in a blood clotting disorder which rapidly alters vital functions. The second response, normally more targeted, is then ineffective: immune cells proliferate and die shortly thereafter. However, these two extreme phenomena do not occur in the survivors. This finding could therefore help refine the search for a therapeutic solution.

3In addition, researchers found that some Ebola-infected patients were asymptomatic and quickly eliminated the virus. To find out more, they initiated a large-scale study in Gabon, collecting blood from 4,500 randomly selected people. The results showed that 10% to 33% of the population had antibodies against Ebola… although they had never experienced any epidemic. While this diffuse immunity is probably acquired in contact with fruit contaminated with bat saliva, its protective effectiveness has yet to be demonstrated.