This noteworthy design was intended to capture a social network of individuals and locations that might include dwellings or workplaces where a patient spent time while symptomatic, or the households of individuals who had contact with the patient during that persons illness or death. In a comparison of cases of EVD among 2,108 individuals in the "immediate" vaccination arm and 1,429 individuals in the "delayed" vaccination arm, Ervebo was determined to be 100% effective in preventing Ebola cases with symptom onset greater than ten days after vaccination. No cases of EVD with symptom onset greater than ten days after vaccination were observed in the "immediate" cluster group, compared with ten cases of EVD in the 21-day "delayed" cluster group.In additional studies, antibody responses to Ervebo were assessed in 477 individuals in Liberia, approximately 500 individuals in Sierra Leone and approximately 900 individuals in Canada, Spain and the U.S. The antibody responses among those in the study conducted in Canada, Spain and the U.S. were similar to those among individuals in the studies conducted in Liberia and Sierra Leone.The safety of Ervebo was assessed in approximately 15,000 individuals in Africa, Europe and North America. The most commonly reported side effects were pain, swelling and redness at the injection site, as well as headache, fever, joint and muscle aches and fatigue.The application for Ervebo in the United States was granted priority review, a tropical disease priority review voucher, and breakthrough therapy designation.
In 2005, a single intramuscular injection of the EBOV or MARV vaccine was found to induce completely protective immune responses in nonhuman primates (crab-eating macaques) against corresponding infections with the otherwise typically lethal EBOV or MARV.In 2010, PHAC licensed the intellectual property on the vaccine to a small U.S. company called Bioprotection Systems, which was a subsidiary of Newlink Genetics, for US $205,000 and "low single-digit percentage" royalties. Newlink had funding from the U.S. Defense Threat Reduction Agency to develop vaccines.In December 2013, the largest-ever Ebola epidemic started in West Africa, specifically, in Guinea. On August 12, the WHO ruled that offering people infected with Ebola the RVSV-ZEBOV vaccine (which at the time was untested on humans) was ethical, and the Canadian government donated 500 doses of the vaccine to the WHO. In October 2014, Newlink had no vaccine in production and no human trials underway, and there were calls for the Canadian government to cancel the contract. In September or October 2014, Newlink formed a steering committee among the interested parties, including PHAC, the NIH, and the WHO, to plan the clinical development of the vaccine.In October 2014, Newlink Genetics began a Phase I clinical trial of rVSV-ZEBOV on healthy human subjects to evaluate the immune response, identify any side effects and determine the appropriate dosage. Phase I trials took place in Gabon, Kenya, Germany, Switzerland, the US, and Canada.