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Prospective Study for the FOLLOW-UP of Human Monkeypox Cases and Smallpox Vaccinees at Risk

Prospective On-site and Questionnaire Study for the FOLLOW-UP of Mpox Cohort at ITM PLUS Evaluation of the Longevity of B- and T-cell Immune Responses in Former Mpox Patients and Vaccine Recipients

Status
Recruiting
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT05879965
Acronym
POQS-FU PLUS
Enrollment
345
Registered
2023-05-30
Start date
2022-10-06
Completion date
2028-06-01
Last updated
2026-03-19

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Monkeypox

Keywords

mpox, immunology, mucosal immunity, sequelae, smallpox vaccination

Brief summary

The goal of this observational study is to describe possible physical and psychological sequelae after an mpox infection and to evaluate the longevity of B- and T-cell immune responses in former mpox patients and vaccine recipients. The main questions it aims to answer are: * Are there any physical or pschological sequelae after mpox infection? * Is the humoral and/or cellular immune response to MPOX (or vaccinia) virus) durable? * Do the patients develop strong local immunity in comparison to systemic immunity? * How long is the virus still detectable in semen, saliva or the ano-rectal region? Participants will answer a questionnaire, samples with blood, saliva and semen as well as anal swabs will be collected. Follow-up visits 8, 16 and 24, 36, 48, and 60 months after infection or vaccination are planned. A healthy control group will be recruited in our HIV-PrEP clinic.

Detailed description

Long-term problems or sequelae after an acute viral infection are described. The study aim is to investigate if long-term symptoms and sequelae can be found in the ITM human mpox infection cohort previously diagnosed and confirmed by PCR at the Institute of Tropical Medicine in Antwerp during the mpox outbreak 2022 in Belgium. The immune response after a natural mpox infection and after a smallpox vaccination will additionally analysed over time. Consented participants Mpox patients, acute infection (n=169, 21% assumed smallpox vaccination in childhood) Mpox patients for follow-up (n=95, 20% assumed smallpox vaccination in childhood) Smallpox vaccinees, two intradermal doses (n=100) Smallpox vaccinees, two subcutaneous doses (n=100) Healthy unvaccinated controls (n=50) Design This prospective longitudinal study has the main objectives to describe possible physical and psychological sequelae after an mpox infection and to evaluate the longevity of B- and T-cell immune responses in former mpox patients and vaccine recipients. Participants are being followed up 8, 16 and 24 months after infection or vaccination. Sample collection Anal eSwabs from patients, controls and vaccinees Saliva (Omnigene-oral and dry swabs) from patients, controls and vaccinees Serum from patients, controls and vaccinees Optional semen samples from patients PBMC samples from a sub-group of patients, controls and vaccinees Laboratory analysis MPXV-PCR on saliva, anorectal and optional semen samples of former mpox patients, vaccinated individuals and healthy controls Mpox-specific antibody profiling from serum Mucosal immunity (IgA, IgG) mpox-specific/reactive from anal swabs and/or saliva Enumeration of MPXV-specific effector-memory T cells via flow cytometry-based AIM or ICS assays (peptide pool stimulation or HLA-restricted multimer-based capture assays) Enumeration of MPXV-specific memory B cells or plasma cells via flow cytometry-ased AIM or ICS assays (recombinant antigen stimulation or HLA-restricted multimer-based capture assays)

Interventions

None listed

Sponsors

Institute of Tropical Medicine, Belgium
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

Mpox patients for immunological study Inclusion criteria * PCR-confirmed mpox infection since May 2022 * ≥18 years * Willingness to provide written informed consent * Willingness to follow the study schedule

Exclusion criteria

* Any vaccination 2 weeks before or after the visits (4 weeks for life-vaccines) * Any immune-compromising drugs or diseases (treated and controlled HIV-infection is no

Design outcomes

Primary

MeasureTime frameDescription
Proportion of individuals with a positive mpox serology in both groups2 yearsTo compare the MPXV-specific serological response in naturally infected mpox male patients 8, 16 and 24 months after onset of symptoms with the MPXV-specific serological response in routinely (=2 either subcutaneous (SC) or intradermal (ID) vaccinations with an interval of 4-8 weeks) vaccinated men against smallpox 8 months after the first vaccination
Proportion of long-term problems or sequelae in mpox patients2 yearsTo describe any possible long-term problem or sequela after an acute human mpox infection diagnosed and confirmed by PCR at ITM since the beginning of the mpox outbreak End of May 2022

Secondary

MeasureTime frameDescription
longevity of humoral and/or cellular immune response to mpox or vaccinia virus2 yearsB-cell and T-cell characteristics in former mpox patients and smallpox vaccinees 8, 16, 24 months after symptom

Countries

Belgium

Contacts

CONTACTStudy Coordinator
bsmekens@itg.be+32(0)33455672
PRINCIPAL_INVESTIGATORNicole Berens-Riha, PhD

Institute of Tropical Medicine

STUDY_DIRECTORLaurens Liesenborghs, PhD

Institute of Tropical Medicine

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 20, 2026