Boosting Ebola vaccines in previously vaccinated individuals
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: a Mix-and-match Phase II RCT
This study is testing if booster shots of Ebola vaccines can safely increase immunity in people from the Democratic Republic of the Congo who have already been vaccinated.
Quick facts
| Phase | Phase 3 |
|---|---|
| Study type | Interventional |
| Enrollment | 624 (estimated) |
| Ages | 18 Years to 50 Years |
| Sex | All |
| Sponsor | Institute of Tropical Medicine, Belgium Academic / other |
| Locations | 2 sites (Goma and 1 other locations) |
| Trial ID | NCT06126822 on ClinicalTrials.gov |
What this trial studies
This randomized controlled trial aims to evaluate the safety and immunogenicity of booster vaccinations with Ervebo® and Zabdeno® in individuals from the Democratic Republic of the Congo (DRC) who have previously received these vaccines. Participants will be divided into groups to receive either a homologous or heterologous booster and will attend clinic visits over six months for blood sample collection to assess immune responses. The study will also monitor safety by recording adverse events and evaluating physical and vital signs.
Who should consider this trial
Good fit: Ideal candidates are individuals aged 18 to 50 who have received either the Ervebo® or the full Zabdeno/Mvabea® vaccine regimen more than four months prior to recruitment.
Not a fit: Patients who have previously experienced active Ebola Virus Disease or have received any additional Ebola vaccine within 30 days prior to recruitment may not benefit from this study.
Why it matters
Potential benefit: If successful, this study could enhance the immune response against Ebola virus in previously vaccinated individuals, potentially improving their protection.
How similar studies have performed: Other studies have shown promise in boosting immune responses with heterologous vaccine schedules, but this specific approach is novel in the context of Ebola vaccination.
Eligibility criteria
Show full inclusion / exclusion 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 The non-vaccinated control group will also adhere to all the above in- and exclusion criteria, with exemption of: * 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 The latter is rather introduced as an additional exclusion criteria: * Subjects who received either the Ervebo® vaccine or the full Zabdeno, Mvabea® vaccine regimen
Where this trial is running
Goma and 1 other locations
- Institut National de Recherche Biomédicale (INRB) — Goma, Democratic Republic of the Congo (Not_yet_recruiting)
- Institut National de Recherche Biomédicale (INRB) — Kinshasa, Democratic Republic of the Congo (Recruiting)
Study contacts
- Principal investigator: Wim Adriaensen, Prof. — Institute of Tropical Medicine
- Study coordinator: Wim Adriaensen, Prof.
- Email: wadriaensen@itg.be
- Phone: +32(0)33455909
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.