Recombinant vesicular stomatitis virus–Zaire Ebola virus (rVSV-ZEBOV), also known as Ebola Zaire vaccine live and sold under the brand name Ervebo, is an Ebola vaccine for adults that prevents Ebola caused by the Zaire ebolavirus. When used in ring vaccination, rVSV-ZEBOV has shown a high level of protection. Around half the people given the vaccine have mild to moderate adverse effects that include headache, fatigue, and muscle pain.
rVSV-ZEBOV is a recombinant, replication-competent viral vector vaccine. It consists of rice-derived recombinant human serum albumin and live attenuated recombinant vesicular stomatitis virus (VSV), which has been genetically engineered to express the main glycoprotein from the Zaire ebolavirus so as to provoke a neutralizing immune response to the Ebola virus.
The vaccine was approved for medical use in the European Union and the United States in 2019. It was created by scientists at the National Microbiology Laboratory in Winnipeg, Manitoba, Canada, which is part of the Public Health Agency of Canada (PHAC). PHAC licensed it to a small company, Newlink Genetics, which started developing the vaccine; Newlink in turn licensed it to Merck in 2014. It was used in the DR Congo in a 2018 outbreak in Équateur province, and has since been used extensively in the 2018–20 Kivu Ebola outbreak, with over 90,000 people vaccinated.
Nearly 800 people were ring vaccinated on an emergency basis with VSV-EBOV when another Ebola outbreak occurred in Guinea in March 2016. In 2017, in the face of a new outbreak of Ebola in the Democratic Republic of the Congo, the Ministry of Health approved the vaccine's emergency use, but it was not immediately deployed.
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 DRC's Institut National pour la Recherche Biomedicale, into the effectiveness of the ring vaccination program, stating that the rVSV-ZEBOV-GP vaccine had been 97.