A Phase 4 interventional study of rVSVDG-ZEBOV-GP Ebola Virus Vaccine (ERVEBO) in Ebola Virus Disease, sponsored by Tulane University. Active, not recruiting at 1 site in Sierra Leone. Open to participants aged 18 Years to 100 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-06-04.
Sponsored by Tulane University · Phase 4, Interventional, and Prevention
This study is a vaccine-related clinical trial which will be conducted by our study team at Kenema Government Hospital (KGH)'s Viral Hemorrhagic Fever Program in collaboration with Tulane University School of Medicine. This study is funded by Merck \& Co., the developers of ERVEBO®. This investigational medicinal product (IMP) was successful in Sierra Leone through the Sierra Leone Trial to Introduce a Vaccine against Ebola (STRIVE) working with the College of Medical and Allied Health Services (COMAHS) at the University of Sierra Leone. ERVEBO® was also successfully tested in Liberia and the Republic of Guinea. These successful trials led to the United States Food and Drug Administration (USFDA) approval of ERVEBO®, as well as approval for therapeutic use in the Democratic Republic of the Congo, Burundi, Ghana, and Zambia.
This particular vaccination study will focus on the anamnestic response to the ERVEBO® vaccine, (full name - rVSVDG-ZEBOV-GP Ebola Virus Vaccine). The original clinical trials conducted excluded Ebola Virus Disease (EVD) survivors from participating. However, with ongoing research, there is evidence of waning immune response and even recurrent infections in EVD survivors.
Ebola virus (EBOV; also known as Zaire ebolavirus, family Filoviridae) is among the most virulent infectious agents known, producing sporadic outbreaks of severe and highly lethal hemorrhagic fever in humans and nonhuman primates (NHPs). The West African Ebola Virus Disease (EVD) Outbreak of 2013 to 2016, which predominantly affected Sierra Leone, Liberia, and Guinea, resulted in 28,601 confirmed cases and 11,308 fatalities.
Multiple reports in the literature of recurrent infections among EVD survivors now exist. Some of these recurrent infections have also resulted in transmission to close contacts of these survivors. In December 2019, the U.S. Food and Drug Administration approved the recombinant Vasicular Stomatitis Virus delta-G (rVSVDG) Zaire Ebolavirus (ZEBOV) Glycoprotein (GP) (rVSVDG-ZEBOV-GP) Ebola vaccine (ERVEBO®; Merck) for use in people 18 years and older. The current literature and data on EBOV antibody levels in survivors suggest that while the humoral immune response to EBOV after natural infections wanes over weeks to months, the response to a single dose of rVSVDG-ZEBOV-GP vaccine is stable over at least two years.
In this pilot study, the investigators hypothesize that vaccination of EVD survivors with rVSVDG-ZEBOV-GP will result in a non-inferior immune response compared to vaccination of non-exposed age- and sex-matched individuals. This study will be an open-label, case-control study of the safety and immunogenicity of the rVSVDG-ZEBOV-GP vaccine comparing EVD survivors and EBOV-naïve community members in Sierra Leone. A total of 40 participants will be recruited and divided 1:1 into EVD survivors (cases) and EBOV-naïve age- and sex-matched community members (controls). Following a two week screening period, participants will be followed for six months post-vaccination.
Subject Population
Twenty EVD survivors and twenty age and sex-matched controls with no clinical history or immunologic evidence of prior EBOV infection will be enrolled. All participants will be citizens of Sierra Leone. In accordance with the currently approved use of the rVSVDG-ZEBOV-GP vaccine in Sierra Leone, all participants will be 18 years or older and pregnant and lactating females will be excluded.
While there is currently an effort to vaccinate all healthcare workers in Sierra Leone, EVD survivors are excluded in the current vaccine roll-out. The investigators plan to recruit EVD survivors including healthcare workers thus enhancing access to the vaccine for this population. All participants will be of African descent. The investigators plan to enroll an equal number of males and females.
104 studies on the registry are indexed under Hemorrhagic Fever, Ebola; 13 are open to participants now.
This study's enrollment of 40 is below the median of 94 across 81 interventional studies indexed under Hemorrhagic Fever, Ebola.
Browse Hemorrhagic Fever, Ebola studies →Tulane University is the lead sponsor of 96 studies on the registry; 23 are open to participants now.
Of its 9 completed or terminated interventional studies of FDA-regulated products, 5 (56%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
EVD survivors
Age- and sex-matched controls
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Live vaccines
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants with a history of admission and discharge from an Ebola Treatment Unit as registered by the Sierra Leone Association of Ebola Survivors (SLAES), and Anti-EBOV GP IgG positive by ELISA at the time of screening.
Biological: rVSVDG-ZEBOV-GP Ebola Virus Vaccine (ERVEBO)
Age- and sex-matched controls who are Anti-EBOV GP IgG negative by ELISA at the time of screening.
Biological: rVSVDG-ZEBOV-GP Ebola Virus Vaccine (ERVEBO)
It is an Ebola virus vaccine
Assess the immunogenicity and durability of rVSVDG-ZEBOV-GP among EVD survivors compared with unexposed age- and sex-matched controls at six months post-vaccination
Serum samples will be tested for the presence of anti-EBOV GP immunoglobulin G (IgG) and anti-EBOV Viral Protein 40 (VP40) IgG using ELISA plates produced by Zalgen Labs, LLC and run according to the manufacturer's instructions.
Time frame: 6 months
Assess the incidence of adverse events after vaccination with rVSVDG-ZEBOV-GP among EVD survivors compared with unexposed age- and sex-matched controls
The investigators will assess the following adverse events at all post-vaccination follow-up time points: arthralgia, diarrhea, fatigue, fever, headache, induration, injection site pain, muscle pain, myalgia, and vomiting. Follow up visits will occur on days 1, 3, 7, 14, 28, 90 and 180 post vaccination.
Time frame: 6 months
Assess the durability of neutralizing antibody titers after immunization with rVSVDG-ZEBOV-GP among EVD survivors compared with unexposed age- and sex-matched controls at six months post-vaccination
The investigators will use Pseudovirus Neutralization Assay that has been adapted from a previously described Lassa pseudovirus to produce Ebola pseudoviruses (EBOVpp). EBOVpp are capable of a single round of replication, when used to infect a human embryonic kidney cell line which is capable of fluorescence.
Time frame: 6 months
Determine Fc-mediated innate effector function profiles in EVD survivors compared to both naïve vaccinees and EVD survivors vaccinated with rVSVDG-ZEBOV-GP.
The investigators will use a bead-based multiplexed platform to measure Fc-mediated effector functional profiles and virus specific antibodies using an established EBOV systems serology platform including: (A) monocyte/macrophage phagocytosis and activation, (B) neutrophil phagocytosis and maturation, (C) Natural Killer (NK) cell activation, and (D) complement deposition.
Time frame: 6 months
Assess the phenotype, function, and durability of EBOV specific T-cell responses in natural immunity (EVD survivors) and response to vaccination with rVSVDG-ZEBOV-GP in EVD survivors and naïve vaccinees
EBOV specific T-cells will be characterized by: (A) EBOV protein stimulation and intracellular cytokine staining, (B) magnetic bead-based assays to assess function in supernatants from stimulated cells, and (C) Two-color Interferon-Gamma and Tumor Necrosis Factor-Alpha (TNFa) Enzyme Linked Immunosorbent Spot (ELISPOT).
Time frame: 6 months
Plan to share: Yes — The Principal Investigator or their designee will be the data manager with responsibility for delegating the receiving, entering, cleaning, querying, analyzing, and storing all data accrued from the study. All data will be entered in paper case record forms and transcribed by double entry into an electronic database. This includes safety data, laboratory data (both clinical and immunological) and outcome data.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form
Time frame: From preliminary interim analysis until the final report of the study, the site owns the data and it is agreed that publication will occur in a timely manner.
Access criteria: All files and source documents will be kept confidentially in locked, fireproof safety cabinets with limited access. The Principal Investigator, co-investigators, and clinical research staff will have access to records. The investigators will permit authorized representatives of the sponsor, regulatory agencies, and monitors to examine (and when required by applicable law, to copy) clinical records for the purposes of quality assurance reviews, audits, and evaluation of the study safety and progress.
No publications or documents are linked to this record.
This study is active, not recruiting, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.
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Tulane University