Surveillance of Vaccine-induced Immunity Against Ebola in Previously Vaccinated Health Care Workers

NCT05313139 | Completed DMC

• 1 other identifier: 1521/21
• Study Type: observational
• Target: 133
• Locations: 1 country
• Sites: 2

Brief Summary

During the previous Ebola virus disease (EVD) outbreaks, the institute National de Recherche Biomédicale (INRB) and other institutional's staff in Democratic Republic of the Congo (DRC) got vaccinated with the rVSV-ZEBOV vaccine. However, the longevity of Ebola virus (EBOV)-specific immune responses after vaccination has not been studied extensively (only 1-2 years) nor comprehensively (only humoral), despite the wide use of this vaccine. With the re-emergence of Ebola in North-Kivu from a previously vaccinated individual, and the new planned vaccination campaign (considering homologous booster doses for previously vaccinated HCW) in light of the new outbreak in Beni, assessing the persistence and quality of vaccine-induced anti-EBOV immune responses is pertinent and timely.

Conditions

Immune Response

Outcome Measures

Primary Outcomes (3)

• EBOV glycoprotein (GP)-specific T and B cell Spot Forming Units

  EBOV glycoprotein (GP)-specific T and B cell Spot Forming Units (SFU) per 10\^6 cells determined by Elipot/Fluorospot assay

  Day 0

• EBOV glycoprotein (GP)-specific T and B cell Spot Forming Units

  EBOV glycoprotein (GP)-specific T and B cell Spot Forming Units (SFU) per 10\^6 cells determined by Elipot/Fluorospot assay

  Day 7

• EBOV glycoprotein (GP)-specific T and B cell Spot Forming Units

  EBOV glycoprotein (GP)-specific T and B cell Spot Forming Units (SFU) per 10\^6 cells determined by Elipot/Fluorospot assay

  Day 28

Secondary Outcomes (13)

• Geometric mean titers (GMT) of GP-specific IgG and neutralizing antibodies (nAb)

  Day 0

• Geometric mean titers (GMT) of GP-specific IgG and neutralizing antibodies (nAb)

  Day 7

• Geometric mean titers (GMT) of GP-specific IgG and neutralizing antibodies (nAb)

  Day 28

• Seroprevalence status based on GP specific antibodies (Ab)

  Day 0

• Seroprevalence status based on GP specific antibodies (Ab)

  Day 7

Study Arms (6)

Unvaccinated participants

Participants who did received the rVSV-ZEBOV vaccine nor had any prior close contact with EBOV patients nor presenting a travel history to East DRC

Primary vaccinated participants

Participants who received a first rVSV-ZEBOV vaccine dose as part of the WHO vaccination campaign organized in Goma region (end of 2021), of which vaccination date and brand is known

Participants vaccinated < 1 year ago (from date of enrollment)

Participants who received a rVSV-ZEBOV vaccine dose less than a year prior to inclusion of which vaccination date and brand is known

Participants vaccinated 1-2 years ago (from date of enrollment)

Participants who received a rVSV-ZEBOV vaccine dose between 1-2 years prior to inclusion of which vaccination date and brand is known

Participants vaccinated 2-3 years ago (from date of enrollment)

Participants who received a rVSV-ZEBOV vaccine dose between 2-3 years prior to inclusion of which vaccination date and brand is known

Participants vaccinated > 3 years ago (from date of enrollment)

Participants who received a rVSV-ZEBOV vaccine dose \> 3 years prior to inclusion of which vaccination date and brand is known

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Health care workers from Institut National de Recherche Biomédicale (INRB) Kinshasa and Institut National de Recherche Biomédicale (INRB) Goma, who previously or recently received (primary and booster dose), or did not receive (cf. controls) the rVSV-ZEBOV vaccine.

You may qualify if:

• Subject is willing and able to give informed consent for participation in the study
• Subject can be contacted by phone, email or physical address
• Subject is aged 18 years or above
• Subject must have a ID card (or other identification document)
• For vaccinated group:
• For unvaccinated group (controls):
• Subject must NOT have received the rVSV-ZEBOV vaccine nor had any prior close contact with EBOV patients

You may not qualify if:

• Subject was previously diagnosed with EVD
• Subject has any contraindication to venipuncture, as determined by clinical judgement

Sponsors & Collaborators

• Institute of Tropical Medicine, Belgium: lead

Study Sites (2)

Institut National de Recherche Biomédicale (INRB)

Goma, Democratic Republic of the Congo

Location

Institut National de Recherche Biomédicale (INRB)

Kinshasa, Democratic Republic of the Congo

Location

Biospecimen

Retention: SAMPLES WITHOUT DNA

Blood sampling, 3x10mL Lithium Heparine tubes collected by venipuncture

Study Officials

• Mulangu Sabue, Prof

  Institut National de Recherche Biomédicale (INRB), Kinshasa

  STUDY CHAIR

• Kavunga Hugo, Prof

  Institut National de Recherche Biomédicale (INRB), Goma

  STUDY CHAIR

• Mukadi Daniel, MD

  Institut National de Recherche Biomédicale (INRB), Goma

  STUDY CHAIR

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 15, 2022
• First Posted: April 6, 2022
• Study Start: December 13, 2021
• Primary Completion: February 1, 2022
• Study Completion: March 3, 2025
• Last Updated: March 19, 2026

Record last verified: 2026-03

Locations

DE (2)