Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
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RECRUITING
PHASE4
40 participants
INTERVENTIONAL
2025-12-01
2026-05-31
Brief Summary
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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
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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
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Keywords
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Study Design
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NON_RANDOMIZED
PARALLEL
PREVENTION
NONE
Study Groups
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Community control
Age- and sex-matched controls who are Anti-EBOV GP IgG negative by ELISA at the time of screening.
rVSVDG-ZEBOV-GP Ebola Virus Vaccine (ERVEBO)
It is an Ebola virus vaccine
Ebola Virus Disease (EVD) survivors
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.
rVSVDG-ZEBOV-GP Ebola Virus Vaccine (ERVEBO)
It is an Ebola virus vaccine
Interventions
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rVSVDG-ZEBOV-GP Ebola Virus Vaccine (ERVEBO)
It is an Ebola virus vaccine
Eligibility Criteria
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Inclusion Criteria
* 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.
* 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.
Exclusion Criteria
* 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.
* 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.
18 Years
100 Years
ALL
Yes
Sponsors
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Kenema Government Hospital
OTHER
Merck Sharp & Dohme LLC
INDUSTRY
Tulane University
OTHER
Responsible Party
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Principal Investigators
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John Schieffelin, MD
Role: PRINCIPAL_INVESTIGATOR
Tulane University
Locations
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Kenema Government Hospital
Kenema, Eastern Province, Sierra Leone
Countries
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Central Contacts
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Facility Contacts
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Robert Samuels, MBChB
Role: primary
Alhaji Turay, BPharm
Role: backup
Other Identifiers
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2023-970
Identifier Type: -
Identifier Source: org_study_id