The Centers for Disease Control and Prevention said Tuesday that it has launched a clinical trial in Sierra Leone of the experimental Ebola vaccine that showed positive results in two previous trials.
Up to 6,000 healthcare workers and other front-line workers in the fight against the Ebola pandemic in Africa are expected to enroll in the study that will test the efficacy and safety of the vaccine candidate rVSV-ZEBOV. The drug was co-developed by drugmakers NewLink Genetics Corp. and Merck & Co., and is derived from strains of the vesicular stomatitis virus, a common animal virus, to carry Ebola protein.
All participants in the new Sierra Leone trial will receive the experimental vaccine. But one group will receive it immediately while another group will receive it after six months. Researchers will evaluate the vaccine's effectiveness by comparing Ebola disease rates in workers who were vaccinated initially with those who were waiting to get the vaccine.
Preliminary findings from two studies involving rVSV-ZEBOV that were recently published in the New England Journal of Medicine showed signs of the drug's ability to provoke an immune response in recipients. Those findings were based on results from Phase 1 trials conducted in the U.S., Africa and Europe between October and December 2014.
“A safe and effective vaccine would be a very important tool to stop Ebola in the future, and the front-line workers who are volunteering to participate are making a decision that could benefit healthcare professionals and communities wherever Ebola is a risk,” CDC Director Dr. Tom Frieden said in a written statement. “We hope this vaccine will be proven effective, but in the meantime, we must continue doing everything necessary to stop this epidemic—find every case, isolate and treat, safely and respectfully bury the dead, and find every single contact.”
More than 10,000 people have died from the Ebola outbreak in West Africa that wracked Guinea, Liberia and Sierra Leone for more than a year. More than 25,000 infected cases have been reported from the three countries as of April 5, according to the latest figures from the World Health Organization.
