Evaluating the long-term effects of a booster dose of MVA-BN vaccine for monkeypox

Evaluation of Long-term Immunogenicity of a Boost Dose of MVA-BN Vaccine

Observational Assistance Publique - Hôpitaux de Paris · NCT06885853

This study is testing how well a booster dose of the MVA-BN vaccine works over time in men over 18 who have already had two doses to help protect against monkeypox.

Quick facts

Study typeObservational
Enrollment90 (estimated)
Ages18 Years and up
SexAll
SponsorAssistance Publique - Hôpitaux de Paris Academic / other
Locations1 site (Paris, Paris)
Trial IDNCT06885853 on ClinicalTrials.gov

What this trial studies

This observational study aims to assess the long-term immunogenicity of a booster dose of the MVA-BN vaccine, which is used to prevent monkeypox. The study focuses on men over 18 years who have previously received two doses of the vaccine and are eligible for a booster. Given the recent emergence of monkeypox outbreaks, particularly among high-risk populations, this research is critical for understanding the vaccine's effectiveness over time. Participants will also be eligible for HIV pre-exposure prophylaxis (PrEP) treatment, which adds an important layer to the study's public health implications.

Who should consider this trial

Good fit: Ideal candidates for this study are men over 18 who have received two doses of the MVA-BN vaccine and are eligible for a booster.

Not a fit: Patients with a history of confirmed monkeypox or contraindications to vaccination will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance vaccination strategies and improve protection against monkeypox for at-risk populations.

How similar studies have performed: Other studies have shown promising results with similar vaccine approaches, particularly in enhancing immunogenicity through booster doses.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Men aged over 18 years
* Have received two doses of MVA-BN vaccine as an initial schedule
* Eligible for a booster dose of MVA-BN (according to the HAS recommendation)
* Be eligible and wish to initiate PrEP-HIV treatment or be followed for PrEP-HIV treatment
* Covered by social security (excluding AME)

Exclusion Criteria:

* History of mpox (virologically confirmed)
* Be under guardianship or curatorship
* Be subject to a judicial protection measure
* Have a contraindication to vaccination against mpox

Where this trial is running

Paris, Paris

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions MonkeypoxMVA-BN booster vaccineHIV pre-exposure prophylaxis
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.