An Immunogenicity and Safety Trial of MVA-BN in Adults Living With HIV for the Prevention of Mpox Infection, in Kinshasa, DRC

NCT06839989 | Recruiting Phase 2 DMC

• 1 other identifier: Mbote-HIVAX
• Study Type: interventional
• Target: 600
• Locations: 1 country
• Sites: 1

Brief Summary

This is an open-label, phase 2, immunogenicity and safety trial of the MVA-BN vaccine for the prevention of mpox in adults living with HIV with different level of CD4 counts in Kinshasa, DRC. The study team aims to investigate whether the administration of 2 standard subcutaneous doses of the Modified Vaccinia Ankara of Bavarian Nordic (MVA-BN) vaccine given 28 days apart, is immunogenic and safe when administered to People Living with HIV (PLHIV) with different levels of CD4 counts in the Democratic Republic of the Congo (DRC). Enrollment will be stratified according to three different subgroups based on CD4 counts assessed during visit 1A: \<200 cells/µL; 200 to 499 cells/µL; ≥ 500 cells/µL. A total of 600 participants will be included in the trial, with 200 participants per subgroup. All participants will be invited to 6 trial visits over a period of 7 months. This study will take place in cooperation with the National Programme for the Fight against AIDS (PNLS), the 'Programme Elargi de Vaccination (PEV)' and the 'Institut National de Santé Publique (INSP)'. As part of the response to the current mpox epidemic in DRC, a large cohort of about 10,000 individuals living in Kinshasa will be vaccinated in this program. Vaccination will take place in the Centre Hospitalier Kabinda (CHK) and the Pakadjuma Health Centre. All people living with HIV (PLHIV) with the intention to be vaccinated in the CHK, will be asked for their willingness to participate in the MBOTE-HIVAX clinical trial until the sample size of 600 participants needed for this clinical trial is reached.

Conditions

Mpox (Monkeypox)

Keywords

MVA-BN; Vaccination; Mpox

Outcome Measures

Primary Outcomes (1)

• Seroconversion rates for monkeypox virus (MPXV) neutralizing antibodies

  Seroconversion two weeks after administration of two standard doses of MVA-BN, defined as either the appearance of an MPXV neutralizing antibody titre (NT50) greater than or equal to the detection limit for initially seronegative participants or more than doubling of the antibody titre compared to baseline for participants seropositive at baseline

  2 weeks after the last vaccine dose

Secondary Outcomes (5)

• Safety and reactogenicity of the MVA-BN vaccine in PLHIV

  Up to day 14 and until end of participation

• Seroconversion rates for vaccinia virus (VACV) neutralizing antibodies

  2 weeks after last vaccine dose

• Waning of MPXV neutralizing antibodies in PLHIV

  On day 14 and month 6

• Waning of VACV neutralizing antibodies in PLHIV

  On day 14 and month 6

• Seroconversion rates and IgG antibody titre dynamics against MPXV and VACV antigens in serum

  day 0 (prior to first dose), Day14, Day 28, Day 28+14 days, Day 28+6Months

Study Arms (3)

CD4 <200

EXPERIMENTAL

Participants in this arm are stratified in the group with participants with a CD4 level below 200cells/µL.

Biological: Mpox vaccination with MVA-BN

CD4 200-499

EXPERIMENTAL

Participants in this arm are stratified in the group with participants with a CD4 level between 200 and 499 cells/µL.

Biological: Mpox vaccination with MVA-BN

CD4 >= 500

EXPERIMENTAL

Participants in this arm are stratified in the group with participants with a CD4 level of 500cells/µL or more.

Biological: Mpox vaccination with MVA-BN

Interventions

Mpox vaccination with MVA-BN BIOLOGICAL

All participants will be vaccinated on day 0 with the MVA-BN vaccine followed by a second injection on day 28.

CD4 200-499; CD4 <200; CD4 >= 500

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Age ≥ 18 years and ≤ 45 years at time of informed consent
• Able and willing to provide written informed consent
• Infected with HIV and receiving combination antiretroviral therapy (ART) for ≥ 8 weeks prior to study entry and vaccination
• Preparedness to follow the study schedule
• Willingness to use contraception for 1 month after each vaccination (only for women of childbearing potential)

You may not qualify if:

• A known history of mpox and/or smallpox
• A known history of vaccination with 1st, 2nd or 3rd generation smallpox vaccines, or vaccine platforms that contain MVA as a vector
• Planned MVA-based vaccination (other than study vaccination) during the trial
• Close contact to a confirmed mpox case in the 3 weeks prior to study enrollment
• Uncontrolled severe infection or other condition requiring hospitalization
• Pregnancy
• History of anaphylaxis or severe allergic reaction to any vaccine or known allergy to one of the components of the study vaccine

Sponsors & Collaborators

• Institute of Tropical Medicine, Belgium: lead
• MSF Médecins Sans Frontières Belgium: collaborator
• Institut National pour la Recherche Biomedicale (INRB): collaborator

Study Sites (1)

Centre Hospitalier Kabinda

Kinshasa, Democratic Republic of the Congo

RECRUITING

MeSH Terms

Conditions

Mpox, Monkeypox

Interventions

smallpox and monkeypox vaccine modified vaccinia ankara-bavarian nordic

Condition Hierarchy (Ancestors)

Poxviridae Infections; DNA Virus Infections; Virus Diseases; Infections; Primate Diseases; Animal Diseases; Rodent Diseases

Study Officials

• Laurens Liesenborghs, MD

  Institute of Tropical Medicine

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Stefanie Bracke, MD

CONTACT

+32 3 3455580; sbracke@itg.be

Elke Verlodt, MSc

CONTACT

everlodt@itg.be

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 17, 2025
• First Posted: February 21, 2025
• Study Start: August 4, 2025
• Primary Completion: December 31, 2025
• Study Completion: December 31, 2025
• Last Updated: August 15, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR

Locations

DE (1)