An electron micrograph of the Ebola virus
|Target disease||Ebola virus|
|AHFS/Drugs.com||Professional Drug Facts|
Recombinant vesicular stomatitis virus–Zaire Ebola virus (rVSV-ZEBOV), also known as Ebola Zaire vaccine live and sold under the brand name Ervebo, is a vaccine for adults that prevents Ebola caused by the Zaire ebolavirus. When used in ring vaccination, rVSV-EBOV 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 vaccine. It consists of a vesicular stomatitis virus (VSV), which has been genetically engineered to express a 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 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 97.5% effective at stopping Ebola transmission, relative to no vaccination.
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.
rVSV-ZEBOV is a live, attenuated recombinant vesicular stomatitis virus in which the gene for the native envelope glycoprotein ( ) is replaced with that from the Ebola virus ( ), 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.
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. 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; Newlink had funding from the U.S. Defense Threat Reduction Agency to develop vaccines, for US $205,000 and "low single-digit percentage" royalties.
In December 2013, the largest-ever Ebola epidemic started in West Africa, specifically, in Guinea. On August 12th, 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. In November 2014, NewLink exclusively licensed rights to the vaccine to Merck for US $50 million plus royalties.
The Phase I study started with a high dose which caused arthritis and skin reactions in some people, and the vaccine was found replicating in the synovial fluid of the joints of the affected people; the clinical trial was halted because of that, then recommenced with a lower dose.
In March 2015, a Phase II clinical trial and a Phase III started in Guinea at the same time; the Phase II trial focused on frontline health workers, while the Phase III trial was a ring vaccination in which close contacts of people who had contracted Ebola virus were vaccinated with VSV-EBOV. In the same report, the WHO communicated that the control arm of the trial was dropped and the trial would expand. However, the design of this study and the high efficacy of the vaccine were questioned.
In January 2016, the GAVI Alliance signed an agreement with Merck under which Merck agreed to provide VSV-EBOV vaccine for future outbreaks of Ebola and GAVI paid Merck US$5 million; Merck will use the funds to complete clinical trials and obtain regulatory approval. As of that date, Merck had submitted an application to the World Health Organization (WHO) through their Emergency Use Assessment and Listing (EUAL) program to allow for use of the vaccine in the case of another epidemic. It was used on an emergency basis in Guinea in March 2016.
Results of the Phase III Guinea trial were published in December 2016. It was widely reported in the media that vaccine was safe and appeared to be nearly 100% effective, but the vaccine remained unavailable for commercial use as of December 2016.
In April 2017, scientists from the U.S. National Academy of Medicine (NAM) published a review of the response to the Ebola outbreak that included a discussion of how clinical trial candidates were selected, how trials were designed and conducted, and reviewed the data resulting from the trials. The committee found that data from the Phase III Guinea trial were difficult to interpret for several reasons. The trial had no placebo arm; it was omitted for ethical reasons and everyone involved, including the committee, agreed with the decision. This left only a delayed treatment group to serve as a control, but this group was eliminated after an interim analysis showed high levels of protection, which left the trial even more underpowered. 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 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. 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 person's 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. The U.S. Food and Drug Administration (FDA) granted approval for Ervebo to Merck & Co., Inc.
2018 Democratic Republic of the Congo Ebola virus outbreak
During an outbreak in the Democratic Republic of the Congo in 2018, the ZEBOV vaccine was used, and what was once contact tracing which numbered 1,706 individuals (ring vaccination which totaled 3,330) was reduced to zero on June 28, 2018. The outbreak completed the required 42-day cycle on July 24.
On August 1, an EVD outbreak was declared in North Kivu DRC. After six months the current totals stand at 735 total cases and 371 deaths; violence in the region has helped the spread of the virus.
- Monath TP, Fast PE, Modjarrad K, et al. (April 2019). "rVSVΔG-ZEBOV-GP (also designated V920) recombinant vesicular stomatitis virus pseudotyped with Ebola Zaire Glycoprotein: Standardized template with key considerations for a risk/benefit assessment". Vaccine: X. 1. 100009. doi:10.1016/j.jvacx.2019.100009. PMC 6668225. PMID 31384731.
- "Ervebo (Ebola Zaire Vaccine, Live) Suspension for intramuscular injection" (PDF). Merck Sharp & Dohme.
- "Ervebo EPAR". European Medicines Agency (EMA). October 16, 2019. Retrieved March 29, 2020.
- Trad MA, Naughton W, Yeung A, et al. (January 2017). "Ebola virus disease: An update on current prevention and management strategies". Journal of Clinical Virology. 86: 5–13. doi:10.1016/j.jcv.2016.11.005. hdl:10144/618818. PMID 27893999.
- Pavot V (December 2016). "Ebola virus vaccines: Where do we stand?". Clinical Immunology. 173: 44–49. doi:10.1016/j.clim.2016.10.016. PMID 27910805.
- Medaglini, D; Siegrist, CA (April 2017). "Immunomonitoring of human responses to the rVSV-ZEBOV Ebola vaccine". Current Opinion in Virology. 23: 88–94. doi:10.1016/j.coviro.2017.03.008. PMID 28460340.
- Mole, Beth (April 16, 2019). "As Ebola outbreak rages, vaccine is 97.5% effective, protecting over 90K people". Ars Technica. Retrieved April 17, 2019.
- Ebola Ring Vaccination Results April 12, 2019 (PDF). World Health Organization (WHO) (Report). April 12, 2019. Retrieved April 17, 2019. Lay summary.
- Marzi, Andrea; et al. (November 2011). "Vesicular Stomatitis Virus–Based Ebola Vaccines With Improved Cross-Protective Efficacy". Journal of Infectious Diseases. 204 (suppl 3): S1066–S1074. doi:10.1093/infdis/jir348. PMC 3203393. PMID 21987743. Retrieved July 31, 2015.
- "First FDA-approved vaccine for the prevention of Ebola virus disease, marking a critical milestone in public health preparedness and response". U.S. Food and Drug Administration (FDA) (Press release). December 19, 2019. Archived from the original on December 20, 2019. Retrieved December 19, 2019. This article incorporates text from this source, which is in the public domain.
- "Ervebo". U.S. Food and Drug Administration (FDA). December 19, 2019. STN: 125690. Retrieved March 28, 2020.
- Grady, Denise (October 23, 2014). "Ebola Vaccine, Ready for Test, Sat on the Shelf". The New York Times. Retrieved December 21, 2019.
- "Merck & Co. Licenses NewLink's Ebola Vaccine Candidate". Genetic Engineering & Biotechnology News. November 24, 2014.
- McKenzie, David (May 26, 2018). "Fear and failure: How Ebola sparked a global health revolution". CNN. Retrieved May 26, 2018.
- "WHO coordinating vaccination of contacts to contain Ebola flare-up in Guinea". World Health Organization (WHO). March 2016. Retrieved May 14, 2016.
- "Congo approves use of Ebola vaccination to fight outbreak". Reuters. May 29, 2017. Retrieved May 29, 2017.
- Maxmen, Amy (2017). "Ebola vaccine approved for use in ongoing outbreak". Nature. doi:10.1038/nature.2017.22024.
- World Health Organization, Regional Office for Africa, Health Emergencies Programme (June 2017). Ebola Virus Disease Democratic Republic of the Congo: External Situation Report 22 (Report). World Health Organization (WHO) Regional Office for Africa. hdl:10665/255645.
- Martínez-Romero C, García-Sastre A (2015). "Against the clock towards new Ebola virus therapies". Virus Res. 209: 4–10. doi:10.1016/j.virusres.2015.05.025. PMID 26057711.
- Shuchman M (May 2015). "Ebola vaccine trial in west Africa faces criticism". Lancet. 385 (9981): 1933–4. doi:10.1016/S0140-6736(15)60938-2. PMID 25979835.
- Choi WY (January 2015). "Progress of vaccine and drug development for Ebola preparedness". Clin Exp Vaccine Res. 4 (1): 11–16. doi:10.7774/cevr.2015.4.1.11. PMC 4313103. PMID 25648233.
- Regules JA; et al. (April 2015). "A Recombinant Vesicular Stomatitis Virus Ebola Vaccine – Preliminary Report". N Engl J Med. 376 (4): 330–341. doi:10.1056/NEJMoa1414216. PMC 5408576. PMID 25830322.
- Hôpitaux Universitaires de Genève FAQs about the context of this clinical trial: Question 22
- The strange tale of Canada's ebola vaccine: Walkom. Commercial rights to a vaccine worth $50 million were sold to a U.S. middleman for $205,000. By Thomas Walkom, The Star, November 25, 2014
- Carly Helfand for FierceVaccine. November 21, 2014 NewLink, Merck sign Ebola vaccine licensing pact
- Zachary Brennan for BioPharma Reporter. November 25, 2014. Merck to manufacture NewLink Ebola vaccine in-house
- Published PCT Application WO2004011488: Recombinant vesicular stomatitis virus vaccines for viral hemorrhagic fevers, claiming priority to US provisional patent application serial number 60/398,552 filed on July 26, 2003.
- Sylvain Baize (2005). "A single shot against Ebola and Marburg virus". Nature Medicine. 11 (7): 720–21. doi:10.1038/nm0705-720. PMID 16015361.
- Steven M. Jones with thirteen others (2005). "Live attenuated recombinant vaccine protects nonhuman primates against Ebola and Marburg viruses". Nature Medicine. 11 (7): 786–90. doi:10.1038/nm1258. PMID 15937495.
- "Ebola outbreak: 1st human trials of Canadian vaccine start in U.S." CBC News. Associated Press. October 13, 2014.
- "Sole Redacted License Agreement for Recombinant Vesicular Stomatitis Virus Vaccines for Viral Hemorrhagic Fevers". Public Health Agency of Canada. October 6, 2014.
- Branswell, Helen (October 20, 2014). "Canada urged to cancel Ebola vaccine licence, transfer rights to bigger company". CTVNews.
- Origins of the 2014 Ebola epidemic (Report). World Health Organization (WHO). January 2015. Retrieved October 8, 2016.
- "Exclusive: Canada to donate its own Ebola vaccine to WHO for use in Africa". Reuters. August 12, 2014.
- Public Health Agency of Canada (August 2, 2013). "Fact Sheet - VSV-EBOV - Canada's vaccine for Ebola".
- Patricia Van Arnum for DCAT. October 21, 2014 Pharmaceutical companies join the effort to develop and produce vaccines and treatments for the Ebola virus
- Branswell, Helen (October 8, 2014). "Canadian Ebola vaccine license holder moving ahead with safety trials". Canadian Press. Retrieved October 13, 2014.
- "A Phase 1 Randomized, Double-Blind, Placebo Controlled, Dose-Escalation Study to Evaluate the Safety and Immunogenicity of Prime-Boost VSV Ebola Vaccine in Healthy Adults". National Institute of Allergy and Infectious Diseases (NIAID). October 9, 2014. Archived from the original on October 17, 2014. Retrieved October 13, 2014.
- Hôpitaux Universitaires de Genève FAQs about the context of this clinical trial: Question 10
- Table of vaccine clinical trials. World Health Organization (WHO) (Report). Retrieved October 14, 2016.
- "Canadian Ebola vaccine development taken over by Merck". Reuters. November 24, 2014.
- Medaglini, D; Harandi, AM; Ottenhoff, TH; Siegrist, CA; VSV-Ebovac, Consortium. (December 9, 2015). "Ebola vaccine R&D: Filling the knowledge gaps". Science Translational Medicine. 7 (317): 317ps24. doi:10.1126/scitranslmed.aad3106. PMC 6858855. PMID 26659569.
- "Q&A on trial of Ebola Virus Disease vaccine in Guinea". World Health Organization (WHO). July 17, 2015. Archived from the original on November 15, 2019. Retrieved November 14, 2019.
- James Gallagher (July 31, 2015). "Ebola vaccine is 'potential game-changer'". BBC News Online. UK. Retrieved July 30, 2015.
- Henao-Restrepo, Ana Maria; et al. (July 31, 2015). "Efficacy and effectiveness of an rVSV-vectored vaccine expressing Ebola surface glycoprotein: interim results from the Guinea ring vaccination cluster-randomised trial". Lancet. 386 (9996): 857–866. doi:10.1016/S0140-6736(15)61117-5. PMID 26248676.
- Metzger, Wolfram G; Vivas-Martínez, Sarai (2018). "Questionable efficacy of the rVSV-ZEBOV Ebola vaccine". Lancet. 391 (10125): 1021. doi:10.1016/S0140-6736(18)30560-9. PMID 29565013.
- Hirshler, Ben; Kelland, Kate (January 20, 2016). "Vaccines alliance signs $5 million advance deal for Merck's Ebola shot". Reuters. Retrieved January 20, 2016.
- Er, Busta; M, Mancher; Pa, Cuff; K, McAdam; G, Keusch (2017). "Integrating Clinical Research Into Epidemic Response: The Ebola Experience". PMID 28696651. Cite journal requires
- Geisbert, TW (December 22, 2016). "First Ebola virus vaccine to protect human beings?". Lancet. 389 (10068): 479–480. doi:10.1016/S0140-6736(16)32618-6. PMID 28017402.
- Lisa Schnirring (December 27, 2016). "Ebola vaccine highly effective in final trial results". CIDRAP. Retrieved December 28, 2016.
- "FDA Accepts Merck's Biologics License Application (BLA) and Grants Priority Review for V920, the Company's Investigational Vaccine for Ebola Zaire Virus" (Press release). September 17, 2019. Retrieved September 17, 2019 – via Business Wire.
- "Major milestone for WHO-supported Ebola vaccine". World Health Organization (WHO) (Press release). October 18, 2019. Archived from the original on November 11, 2019. Retrieved October 19, 2019.
- "First vaccine to protect against Ebola". European Medicines Agency (EMA) (Press release). October 18, 2019. Archived from the original on November 11, 2019. Retrieved November 11, 2019.
- "Ervebo". European Medicines Agency (EMA). October 17, 2019. Archived from the original on November 15, 2019. Retrieved November 15, 2019.
- "Merck's Ervebo [Ebola Zaire Vaccine (rVSVΔG-ZEBOV-GP) live] Granted Conditional Approval in the European Union" (Press release). Merck. November 11, 2019. Archived from the original on November 11, 2019. Retrieved November 11, 2019 – via Business Wire.
- "WHO prequalifies Ebola vaccine, paving the way for its use in high-risk countries". World Health Organization (WHO) (Press release). November 12, 2019. Archived from the original on November 15, 2019. Retrieved November 13, 2019.
- "EBOLA RDC - Evolution de la riposte contre l'épidémie d'Ebola dans les provinces du Nord Kivu et de l'Ituri au Lundi 31 décembre 2018". us13.campaign-archive.com. Retrieved December 31, 2018.
- Berlinger, Joshua. "Congo to begin vaccinating against Ebola". CNN. Retrieved July 2, 2018.
- "EBOLA RDC - Communication spéciale du Ministre de la Santé concernant l'évolution de la neuvième épidémie d'Ebola en RDC". us13.campaign-archive.com. Retrieved July 2, 2018.
- World Health Organization, Regional Office for Africa (2018). "Weekly Bulletin on Outbreak and other Emergencies: Week 26: 23 - 29 June 2018". Weekly Bulletin on Outbreaks and Other Emergencies: 1-23. hdl:10665/272981. License: CC BY-NC-SA 3.0 IGO. Lay summary.
- Schlein, Lisa. "Congo Ebola Outbreak Expected to End Next Week". VOA. Retrieved July 17, 2018.
- "Media Advisory: Expected end of Ebola outbreak". ReliefWeb. Retrieved July 23, 2018.
- "Ebola outbreak in DRC ends: WHO calls for international efforts to stop other deadly outbreaks in the country". World Health Organization (WHO) (Press release). Retrieved July 24, 2018.
- "EBOLA RDC - Evolution de la riposte contre l'épidémie d'Ebola dans les provinces du Nord Kivu et de l'Ituri au Vendredi 4 janvier 2019". us13.campaign-archive.com (in French). Retrieved January 5, 2019.
- "Statement on disruptions to the Ebola response in the Democratic Republic of the Congo". World Health Organization (WHO). Retrieved January 5, 2019.
- Mahamba, Fiston (August 1, 2018). "Congo declares new Ebola outbreak in eastern province". Reuters. Retrieved January 5, 2019.
|Wikinews has related news: Study confirms efficacy of NewLink Genetics ebola vaccine|
- "Scientists hail '100% effective' Ebola vaccine". National Health Service. England. August 3, 2015.
- Marzi A, Robertson SJ, Haddock E, et al. (August 14, 2015). "VSV-EBOV rapidly protects macaques against infection with the 2014/15 Ebola virus outbreak strain". Science. 349 (6249): 739–42. doi:10.1126/science.aab3920. ISSN 0036-8075. PMID 26249231.
|Scholia has a topic profile for RVSV-ZEBOV vaccine.|