Ebola Virus DiseasePhase 4NCT05992480
REVIVE (Response to the Ebola Virus Vaccine)
A Phase 4 study testing rVSVDG-ZEBOV-GP Ebola Virus Vaccine (ERVEBO) in people with Ebola Virus Disease, run by Tulane University at 1 site in Sierra Leone.
Trial summary
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®. Read more about this study
- Who is it for?
- Ages 18 to 100 yearsHealthy volunteers can take part
- Conditions the study is for
- Ebola Virus Disease
- What is being tested?
- rVSVDG-ZEBOV-GP Ebola Virus Vaccine (ERVEBO)
- Type of treatment
- Vaccines
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteSierra Leone
- Study dates
- 1 Dec 2025to Nov 2026
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 100 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- EVD survivors
- History of admission and discharge from an Ebola Treatment Unit as registered by the Sierra Leone Association of Ebola Survivors (SLAES).
- Anti-EBOV GP IgG positive by ELISA at the time of screening.
- ≥18 years of age.
- >45.5 kg (100lbs).
- Willingness to provide informed, written consent.
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- Willingness to undergo all study procedures including rVSVDG-ZEBOV-GP vaccination and multiple blood collections over a period of six months.
- Age- and sex-matched controls
- Anti-EBOV GP IgG negative by ELISA at the time of screening.
- ≥18 years of age.
- Willingness to provide informed consent.
- Willingness to undergo all study procedures including rVSVDG-ZEBOV-GP vaccination and multiple blood collections over a period of six months.
Who cannot join
- Have received the rVSVDG-ZEBOV-GP vaccine.
- Currently participating in another clinical trial involving a vaccine.
- Received a live vaccine within four weeks of screening.
- <18 years of age.
- Weight <45.5kg (or 100 lbs).
- Refusal to provide informed, written consent.
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- Prisoners of other institutionalized individuals.
- Research study staff and their immediate family members.
- Inability to participate in research activities.
- Pregnant and lactating females.
- Known immunocompromised status.
- Known allergy to vaccine components.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: An Open-Label, Case-Control Study to Compare the Anamnestic Response to the Recombinant Vesicular Stomatitis Delta Glycoprotein Zaire Ebola Virus (ZEBOV) Glycoprotein (rVSVDG-ZEBOV-GP) Ebola Virus Vaccine Among Ebola Virus Disease Survivors to the Primary Immune Response Among Naïve Age and Sex-Matched Controls
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.
Read the detailed description
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.
- Conditions
- Ebola Virus Disease
- Being tested
- rVSVDG-ZEBOV-GP Ebola Virus Vaccine (ERVEBO)
- Keywords
- Vaccine, Ebola, Sierra Leone, Ebola survivor
- Medical subject headings
- Hemorrhagic Fever, Ebola
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
rVSVDG-ZEBOV-GP Ebola Virus Vaccine (ERVEBO)Biological
It is an Ebola virus vaccine
| Study group | Role | What they receive |
|---|---|---|
| Ebola Virus Disease (EVD) survivors | Experimental | 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. Receives: Biological: rVSVDG-ZEBOV-GP Ebola Virus Vaccine (ERVEBO) |
| Community control | Active comparator | Age- and sex-matched controls who are Anti-EBOV GP IgG negative by ELISA at the time of screening. Receives: Biological: rVSVDG-ZEBOV-GP Ebola Virus Vaccine (ERVEBO) |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 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.
Measured: 6 months
Secondary outcomes (3)
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.
Measured: 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.
Measured: 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).
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Aug 2023
- Study start1 Dec 2025
- Primary completionNov 2026 (estimated)
- Study completionNov 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Ebola Virus DiseaseStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Prevention
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Model description
- 1:1 survivor to control
- Masking
- None (open label)
- Enrolment
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- Tulane University
- Sponsor type
- University, hospital or other
- Collaborators
- Kenema Government Hospital, Merck Sharp & Dohme LLC
- Responsible party
- Sponsor
- Investigators
- John Schieffelin, MD, Principal investigator, Tulane University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05992480
- Sponsor's protocol ID
- 2023-970
- Status last verified
- Jun 2026
- First submitted
- 7 Aug 2023
- Last updated
- 4 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- 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.
Study at a glance
From the registry record, last updated by the sponsor on 4 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open-Label, Case-Control Study to Compare the Anamnestic Response to the Recombinant Vesicular Stomatitis Delta Glycoprotein Zaire Ebola Virus (ZEBOV) Glycoprotein (rVSVDG-ZEBOV-GP) Ebola Virus Vaccine Among Ebola Virus Disease Survivors to the Primary Immune Response Among Naïve Age and Sex-Matched Controls
- ClinicalTrials.gov ID
- NCT05992480
- Acronym / sponsor ID
- 2023-970
- Conditions
- Ebola Virus Disease
- Keywords
- Vaccine, Ebola, Sierra Leone, Ebola survivor
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 40 participants (actual)
- Lead sponsor
- Tulane UniversityUniversity, hospital or other
- Collaborators
- Kenema Government Hospital, Merck Sharp & Dohme LLC
- Study start
- 1 Dec 2025 (actual)
- Primary completion
- Nov 2026 (estimated)
- Study completion
- Nov 2026 (estimated)
- First posted
- 15 Aug 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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.
Study design
- Primary purpose
- Prevention
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- 1:1 survivor to control
| Arm | Type | Receives |
|---|---|---|
| Ebola Virus Disease (EVD) survivors | Experimental | Biological: rVSVDG-ZEBOV-GP Ebola Virus Vaccine (ERVEBO)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. |
| Community control | Active comparator | 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. |
Who may qualify
- Ages
- 18 to 100 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (12 listed)
- EVD survivors
- Age- and sex-matched controls
Key exclusion criteria (12 listed)
- Have received the rVSVDG-ZEBOV-GP vaccine.
- Currently participating in another clinical trial involving a vaccine.
- Received a live vaccine within four weeks of screening.
- <18 years of age.
- Weight <45.5kg (or 100 lbs).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| rVSVDG-ZEBOV-GP Ebola Virus Vaccine (ERVEBO)It is an Ebola virus vaccine | Biological | Community control, Ebola Virus Disease (EVD) survivors |
Primary outcome
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
Time frame: 6 months
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.
Assess the incidence of adverse events after vaccination with rVSVDG-ZEBOV-GP among EVD survivors compared with unexposed age- and sex-matched controls
Time frame: 6 months
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.
3 secondary outcomes
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
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.
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
Time frame: 6 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Jun 2026.
- Individual participant dataSharing planned: 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.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
John Schieffelin, MD principal investigator
Tulane University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing rVSVDG-ZEBOV-GP Ebola Virus Vaccine (ERVEBO) in people with Ebola Virus Disease, run by Tulane University at 1 site in Sierra Leone.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 12 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 4 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Sierra Leone. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
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 (time frame: 6 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Jun 2026; AzTrials last refreshed its copy on 6 Nov 2026.