Boosting Ebola vaccines in previously vaccinated individuals

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

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.

Why it matters

Who can join: the full rules

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 it's running

• Institut National de Recherche Biomédicale (INRB)
  Kinshasa, Democratic Republic of the Congo Recruiting
• Institut National de Recherche Biomédicale (INRB)
  Goma, Democratic Republic of the Congo Not yet 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

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.