Safety and Immunogenicity of Ervebo® and Zabdeno® Booster Vaccines Against Ebola Virus Following Previous Vaccination with the Zabdeno/Mvabea® or Ervebo® Vaccine Schedules in DRC

NCT ID: NCT06126822

Last Updated: 2025-03-18

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: PHASE3
• Total Enrollment: 624 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-02-25
• Study Completion Date: 2026-10-31

Brief Summary

The goal of this randomized controlled trial is to investigate whether individuals in DRC previously vaccinated with Zabdeno/Mvabea® or Ervebo® vaccine schedules against Ebola virus can be safely and adequately boosted with homologous or heterologous vaccine schedules.

Participants will be randomized to receive either a homologous or heterologous vaccine schedule and will be asked to come to the clinic at prespecified timepoints over a period of 6 months to collect blood samples for comparison of immunological responses against Ebola virus between both schedules. Safety and tolerability of the vaccines will be evaluated by recording Adverse Events (AE's) and grading physical and vital signs evaluations.

Detailed Description

The aim of this randomized controlled with four arms is to investigate whether individuals previously vaccinated with Zabdeno/Mvabea® or Ervebo® vaccine schedules against Ebola virus can be safely and adequately boosted with homologous and heterologous vaccine schedules. We hypothesize that heterologous booster vaccine schedules generate a non-inferior boosting in antibodies and cellular responses against Ebola virus as compared to homologous schedules and incite a similar safety profile.

Based on the predefined variables (living place and time since vaccination), the research team will pre-select and re-contact individuals previously included in the Phase III EBOVAC vaccine database, EBOSURV participant database, and the Programme Élargi de Vaccination (PEV) database. Participants will be contacted by phone and, if they agree to participate, they are scheduled on predefined screening/recruitment days taken place at the 2 recruitment sites: INRB Goma and INRB Kinshasa.

A total of 624 participants will be included, 312 will be previously vaccinated with Zabdeno/Mvabea® and 312 participants with Ervebo®. Within those two groups, half of the participants (n=156) will be randomized to a single Ervebo® booster vaccine and the other half (n=156) to a single Zabdeno® booster vaccine. Participants will be asked to come to the clinic at prespecified timepoints over a period of 6 months to collect blood samples for comparison of antibody- and cellular response against EBOV between homologous and heterologous schedules. Safety and tolerability of the vaccines will be evaluated by recording Adverse Events (AE's) and grading physical and vital signs evaluations. An additional 50 non-vaccinated participants will be recruited in Kinshasa for assay optimization.

In case of insufficient participants living close to the recruitment centers, a community outreach will be undertaken with a lower amount of visits for logistical reasons.

Conditions

Ebola Virus Disease

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: SINGLE

Study Groups

Zabdeno/Mvabea® vaccinated - Zabdeno® booster

Participants previously vaccinated with the Zabdeno/Mvabea® vaccination schedule, will receive a single intramuscular Zabdeno® booster vaccine (0,5 ml) = homologous vaccination scheme.

Group Type: EXPERIMENTAL

Zabdeno® booster

Intervention Type: DRUG

A single Zabdeno® booster vaccination

Zabdeno/Mvabea® vaccinated - Ervebo® booster

Participants previously vaccinated with the Zabdeno/Mvabea® vaccination schedule, will receive a single intramuscular Ervebo® booster vaccine (1 ml) = heterologous vaccination scheme.

Group Type: EXPERIMENTAL

Ervebo® booster

Intervention Type: DRUG

A single Ervebo® booster vaccination

Ervebo® vaccinated - Ervebo® booster

Participants previously vaccinated with Ervebo®, will receive a single intramuscular Ervebo® booster vaccine (1 ml) = homologous vaccination scheme.

Group Type: EXPERIMENTAL

Ervebo® booster

Intervention Type: DRUG

A single Ervebo® booster vaccination

Ervebo® vaccinated - Zabdeno® booster

Participants previously vaccinated with Ervebo®, will receive a single intramuscular Zabdeno® booster vaccine (0,5 ml) = heterologous vaccination scheme.

Group Type: EXPERIMENTAL

Zabdeno® booster

Intervention Type: DRUG

A single Zabdeno® booster vaccination

Interventions

Zabdeno® booster

A single Zabdeno® booster vaccination

Intervention Type: DRUG

Ervebo® booster

A single Ervebo® booster vaccination

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• Subjects who received either the Ervebo® vaccine (MSD), or the full Zabdeno, Mvabea® vaccine regimen (J&J) more than 4 months prior to recruitment
• Subjects between 18 and 50 years of age at time of randomization
• Subject must be willing and able to provide informed consent
• The subject must be in possession of an identification card (or other identification document)
• Agreement to refrain from blood donation and other vaccinations 30 days after booster vaccination
• Agreement to share and discuss participant's medical history, medical records and concomitant medications when relevant

Exclusion Criteria

• Participants who previously experienced active Ebola Virus Disease (EVD)
• Receipt of any vaccine (licensed or experimental) within 30 days prior to recruitment
• Receipt of an additional booster dose of either Ervebo®, Zabdeno®, or any experimental Ebola vaccine
• Incorrect or incomplete primary vaccination scheme with the Zabdeno, Mvabea® (J&J) vaccine
• Administration of immunoglobulins and/or any blood products within three months prior to recruitment.
• Fever (>38°C) within last 24 hours prior to recruitment.
• Any confirmed or suspected immunosuppressive or immunodeficient state (incl. cancer and HIV); asplenia; recurrent severe infections and use of immunosuppressant medication within the last 6 months, except topical or short-term oral steroids.
• Severe and/or uncontrolled cardiovascular disease, respiratory disease, gastrointestinal disease, liver disease, renal disease, endocrine disorder and neurological illness (mild/moderate well controlled comorbidities are allowed)
• History of anaphylaxis, allergic disease or reactions to any component of the study vaccines
• History of bleeding disorder (e.g. factor deficiency, coagulopathy or platelet disorder), or prior history of significant bleeding or bruising following IM injections or venipuncture
• History of any thrombotic disorder, thrombocytopenia, thrombotic thrombocytopenia syndrome (TTP), or heparin-induced thrombocytopenia and thrombosis (HITT)
• Any other significant disease, disorder, planned surgery, or finding which may significantly affect the ability of the volunteer to participate in the study or impair interpretation of the study data
• Suspected or known alcohol or drug dependency
• Subject is not readily available by telephone, email or physical address

• Agreement to refrain from blood donation and other vaccinations 30 days after study vaccination
• Subjects who received either the Ervebo® vaccine, or the full Zabdeno, Mvabea® vaccine regimen more than 4 months prior to recruitment

• Subjects who received either the Ervebo® vaccine or the full Zabdeno, Mvabea® vaccine regimen

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 50 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Institut National pour la Recherche Biomedicale (INRB)

UNKNOWN

Sponsor Role: collaborator

Institute of Tropical Medicine, Belgium

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Wim Adriaensen, Prof.

Role: PRINCIPAL_INVESTIGATOR

Institute of Tropical Medicine

Locations

Institut National de Recherche Biomédicale (INRB)

Goma, , Democratic Republic of the Congo

Site Status: NOT_YET_RECRUITING

Institut National de Recherche Biomédicale (INRB)

Kinshasa, , Democratic Republic of the Congo

Site Status: RECRUITING

Countries

Democratic Republic of the Congo

Central Contacts

Wim Adriaensen, Prof.

Role: CONTACT

wadriaensen@itg.be

+32(0)33455909

Selien Oostvogels Oostvogels

Role: CONTACT

soostvogels@itg.be

Facility Contacts

Kavunga Hugo, Prof

Role: primary

Mukadi Daniel, MD

Role: backup

Mulangu Sabue, Prof

Role: primary

Other Identifiers

1706/23

Identifier Type: -

Identifier Source: org_study_id