Monkeypox (Mpox)Phase 2NCT06549530
Open-label, Multicenter Immunogenicity and Safety Study of MVA-BN Vaccine in Children From 2 Years to Less Than 12 Years of Age Compared to Adults for the Prevention of Smallpox, Mpox, and Related Orthopoxvirus Infections
A Phase 2 study testing MVA-BN in people with Monkeypox (Mpox), run by Bavarian Nordic at 3 sites in 2 countries.
Trial summary
All participants will receive 2 vaccinations of the same dose of Modified Vaccinia Ankara Virus (MVA-BN) vaccine 4 weeks apart (standard regimen). Serum samples for assessment of immune response will be collected at baseline (visit of first vaccination) and at 2 weeks (week 6), 6 months (week 30), and 1 year after the… Read more about this study
- Who is it for?
- Ages 2 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Monkeypox (Mpox)
- What is being tested?
- MVA-BN
- Type of treatment
- Vaccines
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 460 participants
- Where
- 3 sitesin 2 countries
- Study dates
- 21 Oct 2024to 7 May 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 2 to 50 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Who may be able to join
- To be eligible to participate in this trial, an adult individual must meet all the following criteria:
- Age 18 to 50 years at screening
- Male or female sex
- Informed consent form (ICF) signed and dated by the participant after reading the form and being advised of the risks and benefits of the trial in a language understood by the participant and before performance of any trial-specific procedures
- General good health, without clinically relevant medical illness, physical exam findings, or laboratory abnormalities, as determined by the investigator
- Body mass index (BMI) ≥18.5 and ≤35 (calculated as [body weight in kilograms] /[body height in meters] 2)
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- Agreement by female participants of childbearing potential and male participants who are sexually active with a female partner of childbearing potential to use a highly effective method of birth control from at least 30 days prior to administration of the MVA-BN vaccine until 30 days after last vaccination
- Medically acceptable methods of contraception that may be used by the participant and/or partner include combined (estrogen and progestogen containing) hormonal contraception associated with inhibition of ovulation (oral, intravaginal, transdermal), progestogen-only hormonal contraception associated with inhibition of ovulation (oral, injectable, implantable), intrauterine device (IUD), intrauterine hormone releasing system (IUS), bilateral tubal occlusion, vasectomy, or abstinence (abstinence only acceptable if refraining from heterosexual intercourse during the entire period of 30 days prior to administration of the MVA-BN vaccine until 30 days after last vaccination).
- Female participants or partners are not considered to be of childbearing potential if they are at least 1 year post-menopausal (amenorrhea >12 months and follicle stimulating hormone according to local lab values) at screening.
- Willingness to comply with the requirements of the protocol, in the judgment of the investigator
- Pediatric Cohort
- To be eligible to participate in this trial, a child must meet all the following criteria:
- Age ≥2 and <12 years at screening
- Male or female sex
- Informed consent form signed and dated by a parent/guardian after reading the form and being advised of the risks and benefits or the trial in a language understood by the parent/guardian and before performance of any trial-specific procedures
- Assent form signed and dated, for children required by local regulations
- provide consent ≥8 years of age enrolled at sites in Uganda
- children deemed by the investigator and/or local regulations to be capable of assent in Democratic Republic of Congo
- General good health, without clinically relevant medical illness, physical exam findings, or laboratory abnormalities, as determined by the investigator
- Willingness of parent/guardian to comply with the requirements of the protocol, in the judgment of the investigator
Who cannot join
- An individual who meets any of the following criteria will be excluded from participation in this trial:
- For female participants: Pregnancy or breastfeeding
- Acute or chronic medical condition that, in the opinion of the investigator, would render the trial procedures unsafe or would interfere with the evaluation of responses, including but not limited to, neurologic, cardiovascular, respiratory, hepatic, hematologic, rheumatologic, endocrine, gastrointestinal, renal, autoimmune, or immunosuppressive conditions
- History of or active autoimmune disease (vitiligo or thyroid disease requiring thyroid replacement are not exclusions), history of Guillain-Barré syndrome or Reye's syndrome
- Known immunodeficiency syndrome or known or suspected impairment of immunologic functions including, but not limited to, clinically significant liver disease, diabetes mellitus type I, or moderate to severe kidney impairment. Human immunodeficiency virus (HIV) infection under stable Highly active antiretroviral therapy (HAART) (no change within the last three month) and CD4 count >500/ µL is not considered immunodeficient
- Known or reported previous smallpox vaccination, or vaccination with any licensed or investigational poxvirus-based vaccine
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- History of monkeypox, cowpox, or vaccinia infection
- Close contact in the 3 weeks prior to signing the ICF with anyone known to have mpox
- History of malignancy other than squamous cell or basal cell skin cancer, unless there has been surgical excision at least 6 months prior to screening that is considered to have achieved cure
- Clinically significant mental disorder not adequately controlled by medical treatment
- Active or recent (within 6 months before screening) chronic alcohol abuse and/or intravenous and/or nasal drug abuse
- History of allergic disease or reactions likely to be exacerbated by any component of the vaccine, eg, tris(hydroxymethyl)-amino methane, including history of allergic asthma
- Known allergy to aminoglycosides or quinolones
- History of anaphylaxis of severe allergic reaction to any vaccine
- Receipt of or plans to receive any licensed live vaccine from 30 days prior to the trial vaccination until 30 days after vaccination
- Receipt of or plans to receive any licensed nonlive vaccine from 14 days prior to the trial vaccination until 14 days after last trial vaccination
- Use of any investigational or nonregistered agent within 30 days prior to vaccination or plans to receive an investigational agent during the trial
- Recent blood donation (including platelets, plasma, and red blood cells) within 4 weeks prior to screening or planned blood donations during the active trial period
- Chronic systemic administration (defined as more than 14 days) of >5 mg prednisone (or equivalent)/day or any other immune-modifying drugs from 3 months prior to the first trial vaccination to the visit at the end of the active trial period (use of topical, inhaled, ophthalmic, and nasal glucocorticoids is allowed)
- History of organ transplantation, whether or not chronic immunosuppressive therapy. is being administered
- Administration or planned administration of immunoglobulins and/or any blood products from 3 months prior to the first trial vaccination until the visit at the end of the active trial period (packed red blood cells given for an emergency indication in an otherwise healthy person and not required as ongoing treatment is not exclusionary [eg, packed red blood cells given in an emergency during elective surgery])
- History of coronary heart disease, myocardial infarction, angina, congestive heart failure, cardiomyopathy, stroke or transient ischemic attack, uncontrolled high blood pressure, significant arrhythmia with or without corrective/ablative surgery, or any other heart condition under the care of a doctor
- Employment with the investigator or study site, with direct involvement in the proposed study or other studies under the direction of that investigator or study site, or relationship to the investigator or study site employee
- Relationship with Bavarian Nordic as an employee or employee family member, contractor, agent, or business partner or a financial interest in the outcome of the trial
- Pediatric Cohort
- A child who meets any of the following criteria will be excluded from participation in this trial:
- Acute or chronic medical condition that, in the opinion of the investigator, would render the trial procedures unsafe or would interfere with the evaluation of responses, including but not limited to, neurologic, cardiovascular, respiratory, hepatic, hematologic, rheumatologic, endocrine, gastrointestinal, renal, autoimmune, or immunosuppressive conditions
- History of or currently active autoimmune disease (vitiligo or thyroid disease requiring thyroid replacement therapy are not exclusions), history of Guillain-Barré syndrome or Reye's syndrome
- Known immunodeficiency syndrome. or known or suspected impairment of immunologic functions including, but not limited to, clinically significant liver disease, diabetes mellitus type I, or moderate to severe kidney impairment. HIV infection under stable HAART (no change within the last three month) and CD4 count >500/ µL is not considered immunodeficient
- Known or reported previous smallpox vaccination or vaccination with any licensed or investigational poxvirus-based vaccine
- History of monkeypox, cowpox, or vaccina infection
- Close contact in the 3 weeks prior to signing the ICF/assent form with anyone known to have mpox
- History of malignancy (eg, leukemia or lymphoma)
- History of chronic or known neurological disease or deficient development history
- History of allergic disease or reactions likely to be exacerbated by any component of the vaccine, including history of allergic asthma
- Known allergy to aminoglycosides or quinolones
- History of anaphylaxis or severe allergic reaction to any vaccine
- Receipt of or plans to receive any licensed live vaccine from 30 days prior to first trial vaccination until 30 days after last trial vaccination
- Receipt of or plans to receive any licensed nonlive vaccine from 14 days prior to first trial vaccination until 14 days after last trial vaccination
- Use of any investigational or nonregistered agent other than the trial vaccine within 30 days prior to first vaccination or plans to receive an investigational agent during the trial period
- Chronic administration (defined as more than 14 days) of systemic high dose immune suppressant drugs (2 mg/kg/day or more of prednisolone or its equivalent or 20 mg/day or more for children who weigh more than 10 kg) from 6 months prior to first trial vaccination to trial conclusion
- History of organ transplantation, whether or not chronic immunosuppressive therapy. is being administered
- Administration or planned administration of immunoglobulins and/or any blood products from 3 months prior to the first trial vaccination until the visit at the end of the active trial period
- Employment of parent/guardian with the investigator or study site, with direct involvement in the proposed study or other studies under the direction of that investigator or study site, or relationship to the investigator or study site employee
- Relationship of parent/guardian with Bavarian Nordic as an employee or employee family member, contractor, agent, or business partner or a financial interest in the outcome of the trial
Trial locations and contacts
3 sites in 2 countries.
3 sites in 2 countries
Uganda2 sites
Uganda Virus Research Institute
Entebbe
Epicentre Mbarara Research Centre
Mbarara
Democratic Republic of the Congo1 site
University of Kinshasa
Kinshasa
About this study
All participants will receive 2 vaccinations of the same dose of Modified Vaccinia Ankara Virus (MVA-BN) vaccine 4 weeks apart (standard regimen).
Serum samples for assessment of immune response will be collected at baseline (visit of first vaccination) and at 2 weeks (week 6), 6 months (week 30), and 1 year after the second (last) vaccination.
Read the detailed description
Both treatment groups will start with enrollment after all study approvals are in place. For the pediatric group, enrollment will open for both age subgroups (children 6 to <12 years of age and 2 to <6 years of age) at the same time. An independent data monitoring committee (DMC) then will review reactogenicity and adverse events (AEs) from both children and adults after at least 10 children in each age subgroup have received the first vaccination and have completed the visit 1 week later. If the DMC assesses the safety data to be positive, the pediatric age subgroups can be opened to full enrollment.
- Conditions
- Monkeypox (Mpox)
- Being tested
- MVA-BN
- Medical subject headings
- Mpox, Monkeypox
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
MVA-BNDrug
All participants will receive 2 vaccinations of the same dose of MVA-BN vaccine 4 weeks apart (standard regimen).
| Study group | Role | What they receive |
|---|---|---|
| MVA-BN | Experimental | Participants will receive 2 vaccinations at the standard dose of MVA-BN vaccine 4 weeks apart. Receives: Drug: MVA-BN |
What is being measured
The primary outcome is the main question the study is designed to answer.
Immunogenicity of 2 doses of MVA BN
Titer of serum neutralizing antibodies against vaccinia virus as measured by plaque reduction neutralization tests (PRNTs) 2 weeks after the second MVA BN vaccination
Measured: 2 weeks after the second MVA-BN vaccination
Occurrence of Safety Adverse Events (SAE) & Adverse of Event of Special Interest (AESI) events
Occurrence of any SAE at any time during the trial period Occurrence of any AESI at any time during the trial period
Measured: Day 0 to week 56
Secondary outcomes (2)
Neutralizing antibody response
To assess neutralizing antibody response to the MVABN standard regimen
Measured: From day zero to two weeks after the second vaccination
Neutralizing antibody response durability
To assess durability of neutralizing antibody response to the MVABN standard regimen
Measured: Six months and one year after the second vaccination
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Aug 2024
- Study start21 Oct 2024
- Primary completion1 May 2026 (estimated)
- Study completion7 May 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Monkeypox (Mpox)Studies 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 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 460 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Bavarian Nordic
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Coalition for Epidemic Preparedness Innovations
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06549530
- Sponsor's protocol ID
- POX-MVA-045
- Status last verified
- Nov 2025
- First submitted
- 31 Jul 2024
- Last updated
- 24 Nov 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Tshilumba SM, Ruiz PM, Matuvanga TZ, Lemey G, Kimbulu P, Azoum MA, Salloum M, Kasereka G, Mitashi F, Bikioli F, Muteba D, Bisumba A, Van Damme P, Muhindo-Mavoko H, Jordan E, Van Geertruyden JP, Maketa V, Mitashi P, Lariviere Y. Protocol for a phase 3, randomized, double-blind clinical trial evaluating the safety and immunogenicity of the MVA-BN(R) vaccine against mpox in children aged 4 to less than 24 months in the Democratic Republic of the Congo: Data to guide future paediatric vaccination strategies. Vaccine. 2026 Aug 30;89:128890. doi: 10.1016/j.vaccine.2026.128890. Epub 2026 Jun 29.
PubMed 42372625
Study at a glance
From the registry record, last updated by the sponsor on 24 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Open-label, Multicenter Immunogenicity and Safety Study of MVA-BN Vaccine in Children From 2 Years to Less Than 12 Years of Age Compared to Adults for the Prevention of Smallpox, Mpox, and Related Orthopoxvirus Infections
- ClinicalTrials.gov ID
- NCT06549530
- Acronym / sponsor ID
- POX-MVA-045
- Conditions
- Monkeypox (Mpox)
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 460 participants (estimated)
- Lead sponsor
- Bavarian NordicIndustry (pharma, biotech, devices)
- Collaborators
- Coalition for Epidemic Preparedness Innovations
- Study start
- 21 Oct 2024 (actual)
- Primary completion
- 1 May 2026 (estimated)
- Study completion
- 7 May 2026 (estimated)
- First posted
- 12 Aug 2024 (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.
All participants will receive 2 vaccinations of the same dose of Modified Vaccinia Ankara Virus (MVA-BN) vaccine 4 weeks apart (standard regimen).
Serum samples for assessment of immune response will be collected at baseline (visit of first vaccination) and at 2 weeks (week 6), 6 months (week 30), and 1 year after the second (last) vaccination.
Detailed description
Both treatment groups will start with enrollment after all study approvals are in place. For the pediatric group, enrollment will open for both age subgroups (children 6 to <12 years of age and 2 to <6 years of age) at the same time. An independent data monitoring committee (DMC) then will review reactogenicity and adverse events (AEs) from both children and adults after at least 10 children in each age subgroup have received the first vaccination and have completed the visit 1 week later. If the DMC assesses the safety data to be positive, the pediatric age subgroups can be opened to full enrollment.
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 | Experimental | Drug: MVA-BNParticipants will receive 2 vaccinations at the standard dose of MVA-BN vaccine 4 weeks apart. |
Who may qualify
- Ages
- 2 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
Key inclusion criteria (20 listed)
- To be eligible to participate in this trial, an adult individual must meet all the following criteria:
- Age 18 to 50 years at screening
- Male or female sex
- Informed consent form (ICF) signed and dated by the participant after reading the form and being advised of the risks and benefits of the trial in a language understood by the participant and before performance of any trial-specific procedures
- General good health, without clinically relevant medical illness, physical exam findings, or laboratory abnormalities, as determined by the investigator
Key exclusion criteria (45 listed)
- An individual who meets any of the following criteria will be excluded from participation in this trial:
- For female participants: Pregnancy or breastfeeding
- Acute or chronic medical condition that, in the opinion of the investigator, would render the trial procedures unsafe or would interfere with the evaluation of responses, including but not limited to, neurologic, cardiovascular, respiratory, hepatic, hematologic, rheumatologic, endocrine, gastrointestinal, renal, autoimmune, or immunosuppressive conditions
- History of or active autoimmune disease (vitiligo or thyroid disease requiring thyroid replacement are not exclusions), history of Guillain-Barré syndrome or Reye's syndrome
- Known immunodeficiency syndrome or known or suspected impairment of immunologic functions including, but not limited to, clinically significant liver disease, diabetes mellitus type I, or moderate to severe kidney impairment. Human immunodeficiency virus (HIV) infection under stable Highly active antiretroviral therapy (HAART) (no change within the last three month) and CD4 count >500/ µL is not considered immunodeficient
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 |
|---|---|---|
| MVA-BNAll participants will receive 2 vaccinations of the same dose of MVA-BN vaccine 4 weeks apart (standard regimen). | Drug | MVA-BN |
Primary outcome
Immunogenicity of 2 doses of MVA BN
Time frame: 2 weeks after the second MVA-BN vaccination
Titer of serum neutralizing antibodies against vaccinia virus as measured by plaque reduction neutralization tests (PRNTs) 2 weeks after the second MVA BN vaccination
Occurrence of Safety Adverse Events (SAE) & Adverse of Event of Special Interest (AESI) events
Time frame: Day 0 to week 56
Occurrence of any SAE at any time during the trial period Occurrence of any AESI at any time during the trial period
2 secondary outcomes
Neutralizing antibody response
Time frame: From day zero to two weeks after the second vaccination
Neutralizing antibody response durability
Time frame: Six months and one year after the second vaccination
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 24 Nov 2025.
- Derived from this study: PubMed 42372625Tshilumba SM, Ruiz PM, Matuvanga TZ, Lemey G, Kimbulu P, Azoum MA, Salloum M, Kasereka G, Mitashi F, Bikioli F, Muteba D, Bisumba A, Van Damme P, Muhindo-Mavoko H, Jordan E, Van Geertruyden JP, Maketa V, Mitashi P, Lariviere Y. Protocol for a phase 3, randomized, double-blind clinical trial evaluating the safety and immunogenicity of the MVA-BN(R) vaccine against mpox in children aged 4 to less than 24 months in the Democratic Republic of the Congo: Data to guide future paediatric vaccination strategies. Vaccine. 2026 Aug 30;89:128890. doi: 10.1016/j.vaccine.2026.128890. Epub 2026 Jun 29.
- Individual participant dataSharing planned: No
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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 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing MVA-BN in people with Monkeypox (Mpox), run by Bavarian Nordic at 3 sites in 2 countries.
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 20 inclusion and 45 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 24 Nov 2025. 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 Uganda, 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?
Immunogenicity of 2 doses of MVA BN (time frame: 2 weeks after the second MVA-BN vaccination). The study lists 2 primary outcomes in all. 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 NCT06549530, which also lists 1 linked publication.
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 24 Nov 2025.