NCT07592429

Brief Summary

Primary objective The overall objective is to assess the long-term amplitude and durability of the immune responses after mpox virus (MPXV) infection. Primary endpoint The main outcomes are: the presence of neutralizing antibodies in the serum and the presence of detectable mpox virus-specific memory B cells. Neutralizing antibodies titers will be measured with a semi-automated cell-based assay using live mpox virus. Memory B cells will be measured by flow cytometry and other techniques. Secondary objectives

  1. 1.Assess the amplitude and the stability of the MPXV antigen-specific B-cell memory response after infection, against the immunodominant antigens A27, A33, B5, L1, D8, and H3.
  2. 2.Assess the breadth of the B-cell repertoire and its neutralizing capacity in a subset of patients
  3. 3.Assess the humoral immunity using different serological techniques, for the detection and quantification of anti-MPXV antibodies, and assess the seroneutralization capacities of each antibody.
  4. 4.The presence of MPXV antigen-specific B-cell memory. Memory B cells will be measured by flow cytometry and other techniques.
  5. 5.The breadth and neutralizing capacity of the B-cell repertoire in a subset of patients.
  6. 6.The humoral immunity using serological techniques.

Trial Health

65
Monitor

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
60

participants targeted

Target at P25-P50 for not_applicable

Timeline
24mo left

Started Jul 2026

Typical duration for not_applicable

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

May 10, 2026

Completed
8 days until next milestone

First Posted

Study publicly available on registry

May 18, 2026

Completed
1 month until next milestone

Study Start

First participant enrolled

July 1, 2026

Expected
1 year until next milestone

Primary Completion

Last participant's last visit for primary outcome

July 1, 2027

1 year until next milestone

Study Completion

Last participant's last visit for all outcomes

July 1, 2028

Last Updated

May 18, 2026

Status Verified

May 1, 2026

Enrollment Period

1 year

First QC Date

May 10, 2026

Last Update Submit

May 14, 2026

Conditions

Mpox (Monkeypox)

Keywords

mpox virusImmune protectionImmune responseImmunity durationInfection

Outcome Measures

Primary Outcomes (1)

  • The main outcomes are: the presence of neutralizing antibodies in the serum and the presence of detectable mpox virus-specific memory B cells.

    Neutralizing antibodies titers will be measured with a semi-automated cell-based assay using live mpox virus. Memory B cells will be measured by flow cytometry and other techniques.

    Baseline (Day 1)

Study Arms (1)

study population

EXPERIMENTAL

Procedure: Patients included in the ANRS0758s MOSAIC cohort will be recalled \>3 years after their infection to come to hospital to have a review of medical history since mpox infection, a clinical examination in case of symptoms suggestive of a mpox infection and samples taken for the study.

Procedure: blood sampling

Interventions

blood samplingPROCEDURE

Procedure: Patients included in the ANRS0758s MOSAIC cohort will be recalled \>3 years after their infection to come to hospital to have a review of medical history since mpox infection, a clinical examination in case of symptoms suggestive of a mpox infection and samples taken for the study.

study population

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Written informed consent, signed by the participant and the investigator prior to any study-related procedure
  • Person with a blood sample taken within 8 months following mpox infection
  • ≥ 18 years old

You may not qualify if:

  • Individuals who, in the investigator's opinion, are unlikely to comply with study procedures or whose medical condition is incompatible with study participation
  • For France only: person not affiliated to or not benefiting from a social security scheme in accordance with article L1121-11 of the French Public Health Code (Aide Médicale d'Etat \[AME\] does not constitute a social security scheme)
  • Pregnant or breastfeeding women
  • Individuals under guardianship or curatorship, or deprived of liberty by judicial or administrative decision

Contact the study team to confirm eligibility.

Sponsors & Collaborators

MeSH Terms

Conditions

Mpox, MonkeypoxInfections

Interventions

Blood Specimen Collection

Condition Hierarchy (Ancestors)

Poxviridae InfectionsDNA Virus InfectionsVirus DiseasesPrimate DiseasesAnimal DiseasesRodent Diseases

Intervention Hierarchy (Ancestors)

Specimen HandlingClinical Laboratory TechniquesDiagnostic Techniques and ProceduresDiagnosisPuncturesSurgical Procedures, OperativeInvestigative Techniques

Central Study Contacts

Aida TAIEB

CONTACT

+33 (0)1 82 53 35 66aida.taieb@inserm.fr

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NA
Masking
NONE
Purpose
HEALTH SERVICES RESEARCH
Intervention Model
SINGLE GROUP
Sponsor Type
OTHER GOV
Responsible Party
SPONSOR

Study Record Dates

First Submitted

May 10, 2026

First Posted

May 18, 2026

Study Start (Estimated)

July 1, 2026

Primary Completion (Estimated)

July 1, 2027

Study Completion (Estimated)

July 1, 2028

Last Updated

May 18, 2026

Record last verified: 2026-05

Data Sharing

IPD Sharing
Will not share