Evaluate the Safety and Immunogenicity of the MVA-SIBP Vaccine in the Democratic Republic of the Congo

November 19, 2025 updated by: Shanghai Institute Of Biological Products

Phase 2 Double-Blind, Randomized, Controlled Study of MVA-SIBP Vaccine for Mpox in Age De-escalation in the Democratic Republic of the Congo

To evaluate the safety and immunogenicity of the MVA-SIBP vaccine using a double-blind, randomized, controlled, age de-escalation design conducted in Kinshasa, Democratic Republic of the Congo (DRC).

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Given the urgent need for pediatric data and the high burden of mpox in the DRC, this trial will evaluate the safety and immunogenicity of the MVA-SIBP vaccine using a double-blind, randomized, controlled, age de-escalation design conducted in Kinshasa, DRC. The trial is designed to generate critical data to support regulatory approval and broader access to affordable, stable, and scalable mpox vaccines for Africa.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
180

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child
  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Adults: 18 to 45 years inclusive at the time of informed consent. Adolescents: 12 to 17 years inclusive at the time of consent/assent. Children: 2 to 11 years inclusive at the time of consent/assent.
  • Participant is in good general health as determined by medical history, targeted physical examination, and clinical judgment of the investigator.
  • Adults: Able to read and understand the written informed consent, and willing to comply with all study procedures and availability for the entire study duration. Adolescents: Parent(s) or legally acceptable representative(s) able and willing to provide written informed consent; participant able and willing to provide appropriate assent per local regulations and IRB requirements. Children: Parent(s) or legally acceptable representative(s), with the relationship to the child similarly verified and documented on the consent form, and able and willing to provide written informed consent.
  • Willing and able to comply with all study procedures, visit schedule, and follow-up requirements as judged by the investigator.
  • No history of smallpox or mpox vaccination. No history of confirmed or suspected infection with monkeypox, cowpox, or vaccinia virus.
  • Negative serum or urine pregnancy test at screening and prior to each vaccination. Willing to use highly effective contraception from 30 days prior to first vaccination through 60 days after the last dose. Breastfeeding.
  • Resides in the study catchment area and has no plans to relocate for the duration of the study. Has reliable access to a telephone and/or other means of contact.
  • Adults must have been born in 1980 or later. Able to provide direct written informed consent.
  • Adolescents: Able to provide written or written assent as appropriate. Children: Parent(s)/guardian(s) able to provide written informed consent; child able to provide assent if developmentally appropriate.

Exclusion Criteria:

  • Any prior smallpox or mpox vaccination. History of confirmed or suspected infection with monkeypox, cowpox, or vaccinia virus.
  • Close contact, as defined by WHO.
  • Known or suspected immunocompromised state as specified in the protocol.
  • Acute febrile illness (≥38.0°C) or clinically significant infection within 72 hours prior to vaccination. Any acute illness requiring systemic therapy or hospitalization within 14 days prior to enrollment.
  • History of severe allergy or anaphylaxis to any vaccine or vaccine component. History of severe allergic asthma or asthmatic reactions.
  • Pregnant or breastfeeding at screening or planning to become pregnant during the study period.
  • Participation in another clinical trial with an investigational product or vaccine within 6 months prior to enrollment or planned during the study.
  • Receipt of any live vaccine within 28 days or inactivated vaccine within 14 days prior to enrollment or planned within 28 days after any study vaccination.
  • Any medical disease or condition that, in the opinion of the investigator, would place the participant at unacceptable risk, interfere with study objectives, or compromise protocol compliance.
  • Blood transfusion within three months before inclusion. Significant laboratory test result abnormalities should be added as exclusion criteria. Any condition that, in the opinion of the investigator, would preclude safe participation or successful completion of the study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Experimental group 1
MVA-SIBP low dose: low dose monkeypox vaccine produced by Shanghai Institute of Biological Products Co., Ltd. (SIBP)
Biological: MVA-SIBP low dose
Participants received one subcutaneous dose of 0.5ml MVA-SIBP low dose on days 0 and 28, respectively, for a total of two doses.
Experimental: Experimental group 2
MVA-SIBP high dose: high dose monkeypox vaccine produced by Shanghai Institute of Biological Products Co., Ltd. (SIBP)
Biological: MVA-SIBP high dose
Participants received one subcutaneous dose of 0.5ml MVA-SIBP high dose on days 0 and 28, respectively, for a total of two doses.
Active Comparator: Control group
MVA-BN: monkeypox vaccine produced by Bavarian Nordic(BN)
Biological: MVA-BN
Participants received one subcutaneous dose of 0.5ml MVA-BN low dose on days 0 and 28, respectively, for a total of two doses.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Unsolicited adverse events
Time Frame: Day 28 after each dose
An unsolicited AE is any AE reported in addition to those solicited during the clinical study.
Day 28 after each dose
Solicited local adverse events
Time Frame: Day 8 after each dose
That is frequency of occurrence of events pain, erythema, swelling, induration, pruritus at injection site and recorded by memory aid.
Day 8 after each dose
Solicited systemic adverse events
Time Frame: Day 8 after each dose
That is frequency of occurrence of events headache, fatigue, myalgia, fever, chills, nausea and recorded by memory aid.
Day 8 after each dose
Serious Adverse Events(SAEs)
Time Frame: Day 365 after the first dose
To evaluate the incidence of SAE after vaccination.
Day 365 after the first dose
Adverse Events of Special Interest(AESIs)
Time Frame: Day 365 after the first dose
To evaluate the incidence of AESI after vaccination.
Day 365 after the first dose
Medically Attended Adverse Events(MAAEs)
Time Frame: Day 365 after the first dose
To evaluate the incidence of MAAE after vaccination.
Day 365 after the first dose
Grade 3+ related adverse events
Time Frame: Day 28 after each dose
Grade 3+ incidence of adverse events related to vaccination.
Day 28 after each dose

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Plaque Reduction Neutralization Test(PRNT) Geometric Mean Titers(GMT) of vaccinia
Time Frame: Day 0, 28, 56, 181, 365
Neutralizing antibody titer by PRNT against vaccinia virus.
Day 0, 28, 56, 181, 365
PRNTest GMTof mpox
Time Frame: Day 0, 28, 56, 181, 365
Neutralizing antibody titer by PRNT against mpox virus.
Day 0, 28, 56, 181, 365
Seroconversion rate of vaccinia
Time Frame: Day 28, 56, 181, 365
Seroconversion rate is ≥4-fold rise in PRNT titer vs. baseline.
Day 28, 56, 181, 365
Seroconversion rate of mpox
Time Frame: Day 28, 56, 181, 365
Seroconversion rate is ≥4-fold rise in PRNT titer vs. baseline.
Day 28, 56, 181, 365

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Shanghai Institute Of Biological Products

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Hypolite Muhindo Mavoko, University of Kinshasa

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
December 31, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
February 28, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
February 28, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 19, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 19, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 28, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 28, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 19, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
October 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • SIBP-V08-02

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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