MpoxPhase 4MBOTE-TRAXXNCT07499739
Mpox Biology, Outcome, Transmission and Epidemiology - Tracking the Immune Response After mpoX vaCcination (MBOTE-TRAXX): Clinical Study to Monitor the Immunological Response Following Mpox Vaccination in the City of Kinshasa, Democratic Republic of the Congo
A Phase 4 study testing blood sample collection in people with Mpox, run by Institute of Tropical Medicine, Belgium at 3 sites in Democratic Republic of the Congo.
Trial summary
The study Mbote-TRAXX evaluates humoral and cellular immune responses in individuals vaccinated against mpox with the MVA-BN or LC16m8 vaccine administered as part of a routine mpox vaccination campaign in Kinshasa, Democratic Republic of the Congo (DRC). Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Mpox
- What is being tested?
- blood sample collection
- Type of treatment
- Vaccines, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 300 participants
- Where
- 3 sitesDemocratic Republic of the Congo
- Study dates
- 15 May 2026to 15 Dec 2028
- Phase
- Phase 4
- 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 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Any person aged 18 years old or over at the time of giving informed consent, of any gender
- Participant received the MVA-BN or LC16m8 mpox vaccine as part of the national vaccination campaign
- Participant has the capacity and willingness to give informed written consent
- Participant agrees to adhere to the study's follow-up schedule
Who cannot join
None listed.
Trial locations and contacts
3 sites in 1 country.
Democratic Republic of the Congo3 sites
Centre Convivial Kasa-Vubu
Kinshasa
Kinoise
Kinshasa
Kokolo
Kinshasa
About this study
Official title: Mpox Biology, Outcome, Transmission and Epidemiology - Tracking the Immune Response After mpoX vaCcination
The study Mbote-TRAXX evaluates humoral and cellular immune responses in individuals vaccinated against mpox with the MVA-BN or LC16m8 vaccine administered as part of a routine mpox vaccination campaign in Kinshasa, Democratic Republic of the Congo (DRC). Participants will be followed up at multiple time points after vaccination in order to assess the kinetics and durability of the immune response by collection of blood samples. It is planned to include approximately 150 participants vaccinated with MVA-BN and 150 participants vaccinated with LC16m8.
Read the detailed description
The study Mbote-TRAXX evaluates humoral and cellular immune responses in individuals vaccinated against mpox with the MVA-BN or LC16m8 vaccine administered as part of a routine mpox vaccination campaign in Kinshasa, Democratic Republic of the Congo (DRC). Participants will be followed up at multiple time points after vaccination in order to assess the kinetics and durability of the immune response. It is planned to include approximately 150 participants vaccinated with MVA-BN and 150 participants vaccinated with LC16m8. Participants will be followed up in the clinical trial for a period of 24 months with 6 visits: visit 1 (day 0), visit 2 (day 0 + 28 days), visit 3 (day 0 + 59 days), visit 4 (day 0 + 8 months), visit 5 (day 0 + 16 months) and visit 6 (day 0 + 24 months). The study intervention consists of blood samples. At each visit, 10 mL of blood will be collected, and additional blood samples (20 mL per visit) will be taken from a subgroup of participants.
- Conditions
- Mpox
- Being tested
- blood sample collection
- Keywords
- mpox vaccines
- Medical subject headings
- Mpox, Monkeypox
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
blood sample collectionProcedure or surgery
10 mL of blood will be collected at every visit and additional 20 mL blood samples will be taken from a subgroup of participants at every visit.
| Study group | Role | What they receive |
|---|---|---|
| MVA-BN or LC16m8 vaccinated | Other | Participants vaccinated with MVA-BN or LC16m8 vaccine during the national vaccination campaign Receives: Procedure: blood sample collection |
What is being measured
The primary outcome is the main question the study is designed to answer.
To estimate the seroconversion rate for neutralising antibodies against the mpox virus (MPXV) 28 days after administration of an mpox vaccine (MVA-BN or LC16m8)
Seroconversion 28 days after administration of an mpox vaccine, defined as the appearance of an MPXV neutralizing antibody titer (NT50) greater than or equal to the limit of detection in participants who were seronegative at baseline, or at least a two-fold increase in the antibody titer compared to baseline (Day 0) in participants who were seropositive at inclusion
Measured: Day 28 after inclusion
Secondary outcomes (8)
To estimate the positivity rate for neutralizing antibodies against MPXV 59 days and 8 months after administration of an mpox vaccine (MVA-BN or LC16m8).
Positivity rate 59 days and 8 months after administration of an mpox vaccine (MVA-BN or LC16m8), defined as the appearance of an MPXV neutralizing antibody titer (NT50) greater than or equal to the limit of detection for participants who were initially seronegative, or by a two-fold increase or more in antibody titer compared with the value at Day 0 in participants who were seropositive at enrollment.
Measured: Day 59 and Month 8
To analyze the longitudinal evolution of neutralizing antibody titers against MPXV between Day 0, Day 28, Day 59, and Month 8 after administration of an mpox vaccine (MVA-BN or LC16m8).
Neutralizing antibody titers against MPXV measured at Day 0, Day 28, Day 59, and Month 8 after administration of an mpox vaccine (MVA-BN or LC16m8).
Measured: Day 0, Day 28, Day 59 and Month 8
To estimate the positivity rate for binding antibodies (IgG) against MPXV at all sampling time points: Day 0, Day 28, Day 59, Month 8, Month 16, and Month 24 after administration of an mpox vaccine (MVA-BN or LC16m8).
Positivity rate at Day 28, Day 59, Month 8, Month 16, and Month 24 after administration of an mpox vaccine (MVA-BN or LC16m8). The positivity rate is defined by the appearance of median fluorescence intensity (MFI) values greater than the limit of detection for participants who were initially seronegative, or by more than a two-fold increase in antibody titer compared with the value at Day 0 for participants who were seropositive at baseline.
Measured: Day 0, Day 28, Day 59, Month 8, Month 16 and Month 24
To analyze the longitudinal evolution of binding antibody (IgG) titers against MPXV between Day 0, Day 28, Day 59, Month 8, Month 16, and Month 24 after administration of an mpox vaccine (MVA-BN or LC16m8).
Binding antibody (IgG) titers against MPXV measured at Day 28, Day 59, Month 8, Month 16, and Month 24 after administration of an mpox vaccine (MVA-BN or LC16m8), compared with binding antibody (IgG) titers at Day 0.
Measured: Day 0, Day 28, Day 59, Month 8, Month 16, and Month 24
To identify factors associated with weak immune responses, measured by the seroconversion rate of neutralizing antibodies at Day 0, Day 28, Day 59, and Month 8 after administration of an mpox vaccine (MVA-BN or LC16m8).
Seroconversion at Day 0, Day 28, Day 59, and Month 8 after administration of an mpox vaccine (MVA-BN or LC16m8). The association between risk factors and neutralizing antibody titers will be assessed using logistic regression (or mixed-effects logistic regression for the longitudinal analysis).
Measured: Day 0, Day 28, Day 59, and Month 8
To identify factors associated with weak immune responses, measured by the seroconversion rate of binding antibodies (IgG) at Day 0, Day 28, Day 59, Month 8, Month 16, and Month 24 after administration of an mpox vaccine (MVA-BN or LC16m8).
Seroconversion at Day 0, Day 28, Day 59, Month 8, Month 16, and Month 24 after administration of an mpox vaccine (MVA-BN or LC16m8). The association between risk factors and binding antibody (IgG) titers will be assessed using logistic regression (or mixed-effects logistic regression for the longitudinal analysis).
Measured: Day 0, Day 28, Day 59, Month 8, Month 16, and Month 24
To evaluate the tolerability of MVA-BN and LC16m8 vaccines in terms of solicited symptoms occurring up to 28 days after vaccination.
The frequency of solicited local symptoms (pain, redness, swelling, induration, itching, or a distinct mark [only for the LC16m8 vaccine] at the injection site) and solicited systemic symptoms (headache, fatigue, nausea, vomiting, generalized muscle pain, chills, and/or fever greater than or equal to 38.0°C) up to Day 28 after vaccination.
Measured: Day 28
To document post-vaccination mpox virus infections after administration of an mpox vaccine (MVA-BN or LC16m8).
Number of post-vaccination mpox infections. Post-vaccination mpox infections are defined as any laboratory-confirmed mpox infection occurring after vaccination (assessed anamnesticly).
Measured: Month 24
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Mar 2026
- Study start15 May 2026
- Primary completion15 Dec 2026 (estimated)
- Study completion15 Dec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for MpoxStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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 4
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 300 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Institute of Tropical Medicine, Belgium
- Sponsor type
- University, hospital or other
- Collaborators
- Institut National de Recherche Biomedicale (INRB), Programme Elargi de Vaccination de République Démocratique du Congo, National Institute of Public Health of the Democratic Republic of the Congo
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07499739
- Sponsor's protocol ID
- 1998/26
- Acronym
- MBOTE-TRAXX
- Status last verified
- Jun 2026
- First submitted
- 24 Mar 2026
- Last updated
- 11 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 11 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Mpox Biology, Outcome, Transmission and Epidemiology - Tracking the Immune Response After mpoX vaCcination
- ClinicalTrials.gov ID
- NCT07499739
- Acronym / sponsor ID
- MBOTE-TRAXX / 1998/26
- Conditions
- Mpox
- Keywords
- mpox vaccines
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 300 participants (estimated)
- Lead sponsor
- Institute of Tropical Medicine, BelgiumUniversity, hospital or other
- Collaborators
- Institut National de Recherche Biomedicale (INRB), Programme Elargi de Vaccination de République Démocratique du Congo, National Institute of Public Health of the Democratic Republic of the Congo
- Study start
- 15 May 2026 (actual)
- Primary completion
- 15 Dec 2026 (estimated)
- Study completion
- 15 Dec 2028 (estimated)
- First posted
- 30 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The study Mbote-TRAXX evaluates humoral and cellular immune responses in individuals vaccinated against mpox with the MVA-BN or LC16m8 vaccine administered as part of a routine mpox vaccination campaign in Kinshasa, Democratic Republic of the Congo (DRC). Participants will be followed up at multiple time points after vaccination in order to assess the kinetics and durability of the immune response by collection of blood samples. It is planned to include approximately 150 participants vaccinated with MVA-BN and 150 participants vaccinated with LC16m8.
Detailed description
The study Mbote-TRAXX evaluates humoral and cellular immune responses in individuals vaccinated against mpox with the MVA-BN or LC16m8 vaccine administered as part of a routine mpox vaccination campaign in Kinshasa, Democratic Republic of the Congo (DRC). Participants will be followed up at multiple time points after vaccination in order to assess the kinetics and durability of the immune response. It is planned to include approximately 150 participants vaccinated with MVA-BN and 150 participants vaccinated with LC16m8. Participants will be followed up in the clinical trial for a period of 24 months with 6 visits: visit 1 (day 0), visit 2 (day 0 + 28 days), visit 3 (day 0 + 59 days), visit 4 (day 0 + 8 months), visit 5 (day 0 + 16 months) and visit 6 (day 0 + 24 months). The study intervention consists of blood samples. At each visit, 10 mL of blood will be collected, and additional blood samples (20 mL per visit) will be taken from a subgroup of participants.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| MVA-BN or LC16m8 vaccinated | Other | Procedure: blood sample collectionParticipants vaccinated with MVA-BN or LC16m8 vaccine during the national vaccination campaign |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Any person aged 18 years old or over at the time of giving informed consent, of any gender
- Participant received the MVA-BN or LC16m8 mpox vaccine as part of the national vaccination campaign
- Participant has the capacity and willingness to give informed written consent
- Participant agrees to adhere to the study's follow-up schedule
Key exclusion criteria (0 listed)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| blood sample collection10 mL of blood will be collected at every visit and additional 20 mL blood samples will be taken from a subgroup of participants at every visit. | Procedure or surgery | MVA-BN or LC16m8 vaccinated |
Primary outcome
To estimate the seroconversion rate for neutralising antibodies against the mpox virus (MPXV) 28 days after administration of an mpox vaccine (MVA-BN or LC16m8)
Time frame: Day 28 after inclusion
Seroconversion 28 days after administration of an mpox vaccine, defined as the appearance of an MPXV neutralizing antibody titer (NT50) greater than or equal to the limit of detection in participants who were seronegative at baseline, or at least a two-fold increase in the antibody titer compared to baseline (Day 0) in participants who were seropositive at inclusion
8 secondary outcomes
To estimate the positivity rate for neutralizing antibodies against MPXV 59 days and 8 months after administration of an mpox vaccine (MVA-BN or LC16m8).
Time frame: Day 59 and Month 8
To analyze the longitudinal evolution of neutralizing antibody titers against MPXV between Day 0, Day 28, Day 59, and Month 8 after administration of an mpox vaccine (MVA-BN or LC16m8).
Time frame: Day 0, Day 28, Day 59 and Month 8
To estimate the positivity rate for binding antibodies (IgG) against MPXV at all sampling time points: Day 0, Day 28, Day 59, Month 8, Month 16, and Month 24 after administration of an mpox vaccine (MVA-BN or LC16m8).
Time frame: Day 0, Day 28, Day 59, Month 8, Month 16 and Month 24
To analyze the longitudinal evolution of binding antibody (IgG) titers against MPXV between Day 0, Day 28, Day 59, Month 8, Month 16, and Month 24 after administration of an mpox vaccine (MVA-BN or LC16m8).
Time frame: Day 0, Day 28, Day 59, Month 8, Month 16, and Month 24
To identify factors associated with weak immune responses, measured by the seroconversion rate of neutralizing antibodies at Day 0, Day 28, Day 59, and Month 8 after administration of an mpox vaccine (MVA-BN or LC16m8).
Time frame: Day 0, Day 28, Day 59, and Month 8
To identify factors associated with weak immune responses, measured by the seroconversion rate of binding antibodies (IgG) at Day 0, Day 28, Day 59, Month 8, Month 16, and Month 24 after administration of an mpox vaccine (MVA-BN or LC16m8).
Time frame: Day 0, Day 28, Day 59, Month 8, Month 16, and Month 24
To evaluate the tolerability of MVA-BN and LC16m8 vaccines in terms of solicited symptoms occurring up to 28 days after vaccination.
Time frame: Day 28
To document post-vaccination mpox virus infections after administration of an mpox vaccine (MVA-BN or LC16m8).
Time frame: Month 24
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Jun 2026.
- Individual participant dataSharing planned: No
Related trials for Mpox
RecruitingObservational study
Evaluation of Effectiveness and Safety of LC16m8 Mpox Vaccine in the Democratic Republic of Congo (DRC)
Mpox (Monkeypox), Mpox
Enrolling by invitationObservational study
New York City Observational Study of Mpox Immunity
Monkeypox, Mpox
Enrolling by invitation
Smart Analysis and Decision-Making for Emerging Infectious Diseases
Emerging Infectious Diseases, COVID-19
Active, not recruitingPhase 4
Smallpox Vaccine for Mpox Post-Exposure Prophylaxis: A Cluster RCT
Monkeypox
RecruitingPhase 2
A Randomized Clinical Trial Investigating the Safety, Reactogenicity, and Immunogenicity After Immunization With an mRNA-based Mpox Vaccine Candidate in Africa
Mpox (Monkeypox), Smallpox
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing blood sample collection in people with Mpox, run by Institute of Tropical Medicine, Belgium at 3 sites 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 4 inclusion and 0 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 11 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites 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 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
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?
To estimate the seroconversion rate for neutralising antibodies against the mpox virus (MPXV) 28 days after administration of an mpox vaccine (MVA-BN or LC16m8) (time frame: Day 28 after inclusion). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 11 Jun 2026.