While the goal is to vaccinate people as early as possible during outbreaks, prior to exposure to Ebola virus disease, the results of the Epicentre study show that the vaccine protects against the risk of death from Ebola infection even when people are vaccinated late, i.e. after having been exposed to Ebola virus disease. In addition, no antagonistic effect between vaccination and treatment against Ebola was observed in this study.
“Vaccination after exposure to a person infected with Ebola virus disease, even when administered shortly before the onset of symptoms, still confers significant protection against death,” says Rebecca Coulborn, epidemiologist at Epicentre.
“The reduced risk of death due to vaccination is in addition to the reduction due to Ebola-specific treatment, regardless of the delay before treatment.”
This study provides further evidence of the importance of vaccination against Ebola during the epidemics that regularly occur in sub-Saharan Africa. These are most often caused by the Zaire Ebola virus species, which is associated with high mortality. Since 2019, two vaccines, rVSVΔG-ZEBOV-GP and Ad26.ZEBOV/MVA-BN-Filo, have obtained WHO pre-qualification against this strain.
“In addition to the direct benefit, our results allow us to consider combining vaccination and treatment of patients who have been in direct contact with a person with confirmed Ebola virus disease in order to reduce the risk of illness and death,” says Etienne Gignoux, director of Epicentre’s Epidemiology and Training Department.
Fonte original msf.org