'The results of this trial were positive and very promising; all 3 dose levels of the VSV [vesicular stomatitis virus] Ebola vaccine were well-tolerated by participants, and no safety concerns were identified,' says Dr. May ElSherif.
Several Ebola vaccine candidates are being assessed in ongoing or recently completed phase 1, 2, and 3 trials in various parts of the world. This VSV-Ebola vaccine (formal name: rVSVÎ'G-ZEBOV-GP) was developed at the Canadian National Microbiology Laboratory of the Public Health Agency of Canada. A similar parallel trial was conducted at the Walter Reed Army Institute of Research (WRAIR) in the United States.
Wild type VSV primarily infects animals (e.g., cattle and horses) and rarely infects humans.
Data from this trial and others indicated an optimum dose of 20 million pfu that will be assessed among people with compromised immune systems in areas where Ebola is endemic. An upcoming study at 2 sites in Africa, as well as in Montréal and Ottawa in Canada, will test the safety and protection levels of the VSV-Ebola vaccine in HIV-infected adults and adolescents. A completed phase 3 trial showed that the vaccine is effective in preventing EVD in contacts of recently confirmed cases.
Given the ongoing presence of Ebola, 'these facts underscore the importance of continuing efforts and collaborations that may ultimately lead to licensed Ebola vaccines that would protect humans and prevent or control outbreaks in the future,' conclude the authors.
The study, led by Canadian researchers, is published in CMAJ (Canadian Medical Association Journal).