The committee found that under an intention-to-treat analysis, the rVSV-ZEBOV vaccine might have had no efficacy, agreed with the authors of the December 2016 report that it probably had some efficacy, but found statements that it had substantial or 100% efficacy to be unsupportable.In April 2019, following a large-scale ring-vaccination scheme in the DRC outbreak, preliminary results showed that the vaccine had been 97.5% effective at stopping Ebola transmission, relative to no vaccination.In September 2019, the U.S. Food and Drug Administration (FDA) accepted Mercks Biologics License Application and granted priority review for the vaccine.In October 2019, the European Medicines Agency (EMA) recommended granting conditional marketing authorization for the rVSV-ZEBOV-GP vaccine.In November 2019, the European Commission granted a conditional marketing authorization to Ervebo and the World Health Organization (WHO) prequalified an Ebola vaccine for the first time, indicating that the vaccine met WHO standards for quality, safety and efficacy, and allowing UN agencies and GAVI to procure vaccine for distributions.In December 2019, Ervebo was approved for use in the United States.The approval of Ervebo was supported by a study conducted in Guinea during the 2014-2016 outbreak in individuals 18 years of age and older. The study was a randomized cluster (ring) vaccination study in which 3,537 contacts, and contacts of contacts, of individuals with laboratory-confirmed Ebola virus disease (EVD) received either "immediate" or 21-day "delayed" vaccination with Ervebo.
In 2017, in the face of a new outbreak of Ebola in the Democratic Republic of the Congo, the Ministry of Health approved the vaccines emergency use, but it was not immediately deployed. Effectiveness
In April 2019, following a large-scale ring-vaccination scheme in the DRC outbreak, the WHO published the preliminary results of its research, in association with the DRCs Institut National pour la Recherche Biomedicale, into the effectiveness of the ring vaccination program, stating that the rVSV-ZEBOV-GP vaccine had been 97.5% effective at stopping Ebola transmission, relative to no vaccination. Side effects
Systemic side effects include headache, feverishness, fatigue, joint and muscle pain, nausea, arthritis, rash, and abnormal sweating. Injection-site side events include injection-site pain, swelling, and redness. Biochemistry
rVSV-ZEBOV is a live, attenuated recombinant vesicular stomatitis virus (VSV) in which the gene for the native envelope glycoprotein (P03522) is replaced with that from the Ebola virus (P87666), Kikwit 1995 Zaire strain. Manufacturing of the vaccine for the Phase I trial was done by IDT Biologika. Manufacturing of vaccine for the Phase III trial was done by Merck, using the Vero cell line, which Merck already used to make its RotaTeq vaccine against rotavirus. History
Scientists working for the Public Health Agency of Canada (PHAC) created the vaccine, and PHAC applied for a patent in 2003. From 2005, to 2009, three animal trials on the virus were published, all of them funded by the Canadian and U.S. governments.