Efficacy and effectiveness of an rVSV-vectored vaccine in preventing Ebola virus disease

The Ebola ça Suffit clinical trial, funded in part by the World Health Organization, evaluated the potential of a candidate vaccine to protect against Ebola virus.

The Ebola ça Suffit clinical trial, funded in part by the World Health Organization, evaluated the potential of a candidate vaccine to protect against Ebola virus. After identifying laboratory-confirmed cases of the disease in the west African nations of Guinea and Sierra Leone, contacts and contacts of contacts linked to infected persons were tested for response to the recombinant, replication competent vesicular stomatitis virus-based vaccine. Adults who were not pregnant, breastfeeding, or severely ill were randomized to immediate vaccination with rVSV-ZEBOV or vaccination after 21 days. The trial eventually was opened to children 6–17 years and switched to immediate vaccination for any and all participants. During the randomization phase of the study, 2,119 participants were immediately vaccinated and 2,041 received the vaccine 3 weeks later. There were 16 cases of Ebola virus that surfaced in the delayed-vaccination group 10 days or more after randomization; but none occurred among those who were vaccinated right away, for a vaccination efficacy rate of 100% in this cohort. Even after the randomized stage of the trial, no cases developed among children or additional participants who received immediate vaccination. Moreover, adverse were considered mild and indicate no safety concerns for adult or pediatric recipients.