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Mpox (Monkeypox)Phase 2Mbote-HIVAXNCT06839989

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

A Phase 2 study testing Mpox vaccination with MVA-BN in people with Mpox (Monkeypox), run by Institute of Tropical Medicine, Belgium at 1 site in Democratic Republic of the Congo.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
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Trial 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. Read more about this study

Who is it for?
Ages 18 to 45 years
Conditions the study is for
Mpox (Monkeypox)
What is being tested?
Mpox vaccination with MVA-BN
Could I receive a placebo?
No, everyone receives an active treatment
How many people
600 participants
Where
1 siteDemocratic Republic of the Congo
Study dates
4 Aug 2025to 30 Nov 2026
Phase
Phase 2
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 45 years
  • All sexes
  • No healthy volunteers
  • Adult

Who may be able to join

  • 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)

Who cannot join

  • 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

Trial locations and contacts

1 site in 1 country.

Democratic Republic of the Congo1 site

  • Centre Hospitalier Kabinda

    Kinshasa

Other trials in Democratic Republic of the Congo

About this study

Official title: The Mpox Biology, Outcome, Transmission and Epidemiology Project - HIV Immunization and Vaccination Against Mpox eXposure Trial

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).

Read more

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.

Being tested
Mpox vaccination with MVA-BN
Keywords
MVA-BN, Vaccination, Mpox
Medical subject headings
Mpox, Monkeypox

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Mpox vaccination with MVA-BNBiological

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

Study groups in NCT06839989
Study groupRoleWhat they receive
CD4 <200ExperimentalParticipants in this arm are stratified in the group with participants with a CD4 level below 200cells/µL.
Receives: Biological: Mpox vaccination with MVA-BN
CD4 200-499ExperimentalParticipants in this arm are stratified in the group with participants with a CD4 level between 200 and 499 cells/µL.
Receives: Biological: Mpox vaccination with MVA-BN
CD4 >= 500ExperimentalParticipants in this arm are stratified in the group with participants with a CD4 level of 500cells/µL or more.
Receives: Biological: Mpox vaccination with MVA-BN

What is being measured

The primary outcome is the main question the study is designed to answer.

  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

    Measured: 2 weeks after the last vaccine dose

Secondary outcomes (5)

  1. Safety and reactogenicity of the MVA-BN vaccine in PLHIV

    Solicited local AEs (pain, redness, swelling, induration, and itch at the injection site) and systemic AEs (generalized myalgia, headache, fatigue, nausea and/or vomiting, chills and/or fever (≥ 38.0°C)) up to day 14 post vaccination

    Unsolicited AEs up to day 14 post vaccination

    SAEs until the end of participation

    Measured: Up to day 14 and until end of participation

  2. Seroconversion rates for vaccinia virus (VACV) neutralizing antibodies

    Seroconversion two weeks after administration of two standard doses of MVA-BN, defined as either the appearance of an VACV 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.

    Measured: 2 weeks after last vaccine dose

  3. Waning of MPXV neutralizing antibodies in PLHIV

    The ratio between neutralizing antibody titre against MPXV at 6 months (D28 + 6M) versus 14 days (D28 + 14 days) after administration of two standard doses of MVA-BN.

    Measured: On day 14 and month 6

  4. Waning of VACV neutralizing antibodies in PLHIV

    The ratio between neutralizing antibody titre against VACV at 6 months (D28 + 6M) versus 14 days (D28 + 14 days) after administration of two standard doses of MVA-BN.

    Measured: On day 14 and month 6

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

    The absolute IgG antibody titre against the following antigens: A35R, H3L, B2R, A5L, A27L, B6R, E8L and A29L from mpox, and A33R and B5 from vaccinia virus at D14, D28 (second dose), D28+14d, D28+6M after administration of two standard doses of MVA-BN, be defined as either the appearance of Median Fluorescent Values (MFI) greater than the detection limit for initially seronegative participants or more than doubling of the antibody titre compared to baseline for participants seropositive at baseline.

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

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted21 Feb 2025
  2. Study start4 Aug 2025
  3. Primary completion20 May 2026 (estimated)
  4. Study completion30 Nov 2026 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Prevention
Allocation
Non-randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
600 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06839989
Sponsor's protocol ID
Mbote-HIVAX
Acronym
Mbote-HIVAX
Status last verified
May 2026
First submitted
17 Feb 2025
Last updated
19 May 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Mpox vaccination with MVA-BN in people with Mpox (Monkeypox), run by Institute of Tropical Medicine, Belgium at 1 site in Democratic Republic of the Congo.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 19 May 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Democratic Republic of the Congo. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Seroconversion rates for monkeypox virus (MPXV) neutralizing antibodies (time frame: 2 weeks after the last vaccine dose). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT06839989.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 May 2026.

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