Vaccine Info

Ervebo Ebola Vaccine

Description

Ervebo, V920 (rVSVΔG-ZEBOV-GP), is a recombinant, replication-competent Ebola vaccine, consisting 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.

Merck & Co. Inc. licensed the global R&D and manufacturing rights for Newlink Genetics Corp.'s phase I Ebola vaccine. The Public Health Agency of Canada, which originally developed the vaccine, retained noncommercial rights in the agreement.

Indication

Merck's Ervebo V920 (rVSVΔG-ZEBOV-GP) is an investigational Ebola vaccine candidate that prevents the onset of Ebola Zaire.

Dosage

Ervebo V920 (rVSVΔG-ZEBOV-GP) is administered as an intramuscular injection.

And since the beginning of the DRC Ebola vaccination program on August 8, 2018, approximately 164,000 persons have been vaccinated with Merck’s v920.

As of June 2019, there were roughly 500,000 Ebola vaccine doses available, with another 200,000 doses currently in production.

Moreover, a recent analysis estimated Ervebo Ebola Vaccine Efficacy at 97.5 percent. 

The Democratic Republic of Congo's Health Minister called for Merck’s experimental Ebola vaccine Ervebo v920 (rVSV∆G-ZEBOV-GP) to be fully licensed. 

Dr. Kalenga said he ‘preferred to use just one Ebola vaccine, stating, “It would perturb the population to be faced with several different types of vaccines and that would muddle the message. And, as you know in complex outbreak response, the message needs to be simple and clear.” 

People at highest risk (contacts and contacts of contacts) will now receive 0.5ml of the Ervebo Ebola vaccine instead of 1ml. This dosage is equal to that used in the successful Ebola ça suffit ring vaccination trial in Guinea in 2015 and is expected to provide the same level of protection.

The process of creating Ebola vaccination rings around all people at risk of contracting Ebola has been an effective way to prevent more people from becoming infected.

Additionally, the use of pop-up and targeted geographic approaches to identify those needing Ebola vaccination make the ring vaccination process faster, more secure, and more responsive to community feedback. 

Furthermore, vaccinating those who could be part of tertiary chains of transmission, such as people in villages and neighborhoods where cases have been reported within the past 21 days has helped prevent the spread.

Detection

Ebola virus can be detected in blood after the onset of symptoms. It may take up to three days after symptoms start for the virus to reach detectable levels. Polymerase chain reaction (PCR) is one of the most commonly used diagnostic methods because of its ability to detect low levels of the Ebola virus, says the CDC.   

On October 11, 2019, the U.S. Food and Drug Administration (FDA) announced the marketing approval of a rapid diagnostic test (RDT) to detect Ebola virus antigens in human blood from certain living individuals. The OraQuick Ebola Rapid Antigen test provides a rapid, presumptive Ebola diagnosis, that must be confirmed.  Furthermore, a negative test result does not rule out Ebola virus infection.

Updates

November 11, 2019, The European Commission announced the granting of marketing authorization to Merck Sharp & Dohme B.V. for its Ebola Zaire vaccine.

October 18, 2019, EMA’s human medicines committee (CHMP) has recommended granting a conditional marketing authorization in the European Union for Ervebo V920 (rVSVΔG-ZEBOV-GP),

July 10, 2019,  The DRC’s Minister of Health decided that ‘due to the lack of sufficient scientific evidence on the efficacy and safety of other Ebola vaccine candidates, as well as the risk of confusion among the population, it was decided that no additional clinical vaccine trials will be allowed throughout the country.’  

Which means, Merck's V920 will be the only Ebola Vaccine available in the DRC.

May 23, 2019, The Ethics Committee of the School of Public Health of the University of Kinshasa approved the amendment of the compassionate belt vaccination protocol for the rVSV-ZEBOV vaccine aimed at expanding the targets pregnant women after the first trimester and lactating women identified as contacts. For minors, it is maintained that children can be vaccinated from the age of 6 years. Between 26 November 2018 and 26 May 2019, 319 pregnant women and 603 lactating women registered as contacts could not be vaccinated. 

Clinical Trial: NCT02503202  Phase 3: Evaluation of the Safety and Immunogenicity of Three Consistency Lots and a High-Dose Lot of rVSV-ZEBOV-GP (V920 Ebola Vaccine) in Healthy Adults (V920-012)

  • This Phase 3 study evaluated the safety and immunogenicity of 3 consistency lots and a high-dose lot of rVSV-ZEBOV-GP (V920 Ebola Vaccine) in healthy adults. The primary purpose of this study was to demonstrate consistency in the immune responses of participants receiving 3 separate lots of V920 through 28 days postvaccination. In addition to the 3 lot groups, a high-dose group and a placebo group were studied. A subset of participants representative of all treatment groups continued through 24 months postvaccination in the extension study for the evaluation of long-term safety. The primary hypothesis states that the geometric mean titer of anti-Zaire ebolavirus envelope (ZEBOV) glycoprotein antibody at 28 days postvaccination is equivalent across the three consistency lots.

Clinical Trial: NCT03031912  Phase 2: African-Canadian Study of HIV-Infected Adults and a Vaccine for Ebola - ACHIV-Ebola 

  • This Phase 2 study s a randomized, placebo-controlled, multi-site, double-blind trial of V920 (rVSVΔG-ZEBOV-GP) Ebola Virus vaccine candidate in subjects with HIV infection to be conducted in conformance with Good Clinical Practices. The study will take place at 2 Canadian sites (Centre Hospitalier de l'Université de Montréal and Ottawa General Hospital) and 2 African sites (Centre MURAZ, Burkina Faso and Centre Hospitalier National Aristide Le Dantec, Dakar, Senegal). 

Clinical Trial NCT02314923: Placebo-Controlled, Dose-Response, Safety and Immunogenicity Study of Vesicular Stomatitis Virus (VSV) Ebola Vaccine in Healthy Adults (V920-004)

  • This is a Phase 1 safety and tolerability study to evaluate a novel vaccine to Ebola using a live replicating vesicular stomatitis virus (VSV) replacing the gene encoding the G envelope glycoprotein with the gene encoding the envelope glycoprotein from the Zaire strain of Ebola (VSVΔG-ZEBOV also known as BPSC-1001).
Updated
November 14th, 2019