VSV-ZEBOV, a second experimental Ebola vaccine, is currently undergoing human trials both at the National Institute of Health’s (NIH) Clinical Center in Bethesda, Maryland, and at the Walter Reed Army Institute of Research (WRAIR) in Silver Spring, Maryland, according to a press release from the agency.
“The need for a vaccine to protect against Ebola infection is urgent,” said Anthony S. Fauci, MD, NIAID director. “NIH welcomes the opportunity to collaborate with the U.S. Department of Defense to conduct human clinical tests of another promising, and hopefully, successful, Ebola vaccine candidate.”
The VSV-ZEBOV vaccine, developed by the Public Health Agency of Canada, is based partially on a genetically engineered version of vesicular stomatitis virus (VSV), a disease that primarily affects rodents and livestock.
In the VSV-ZEBOV vaccine, the outer protein of the vesicular stomatitis virus is replaced with a gene segment from outer protein of the Zaire Ebola virus species. “The investigational VSV-ZEBOV vaccine cannot cause a vaccinated individual to become infected with Ebola,” noted the agency.
To gauge the effectiveness and immunogenicity of the VSV-ZEBOV vaccine, the NIH investigators plan to study the effect of the vaccine on 39 healthy adults, aged 18 to 65 years. Participants will be randomly split into one of three groups; in each group, 10 will be assigned to receive the experimental vaccine and three will be assigned placebo
During the initial visit, the first group will receive the lowest dosage of the vaccine, while the other two groups will receive increased doses. After 28 days, all participants will receive a second injection at the same dosage level.
While NIH researchers evaluate the new vaccine candidate’s effectiveness as a prime-boost strategy, the scientists at WRAIR will be evaluating the efficacy of VSV-ZEBOV as a single-dose injection.
“This is being done to evaluate in real-time the safety profile of the investigational vaccine when provided at different dosages and compare the immune responses induced by one injection versus two injections,” explained NIH.
Initial results of both VSV-EBOV and a separate experimental Ebola vaccine, which started human trials in early September, are expected by the end of 2014, reported the National Institute of Health.