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

Recruiting

• Conditions: Monkeypox

• Registration Number: NCT05879965
• Lead Sponsor: Institute of Tropical Medicine, Belgium

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 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)

Study Timeline

• Study Start: 2022-10-06
• Status Verified: 2023-05
• Study First Submitted: 2023-05-19
• Study First Submitted QC: 2023-05-19
• Last Update Submitted: 2023-05-19
• Study First Posted: 2023-05-30
• Last Update Posted: 2023-05-30
• Primary Completion: 2024-10
• Study Completion: 2024-10

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 345

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Proportion of long-term problems or sequelae in mpox patients	2 years	To 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
Proportion of individuals with a positive mpox serology in both groups	2 years	To 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

Secondary Outcome Measures

Name	Time	Method
longevity of humoral and/or cellular immune response to mpox or vaccinia virus	2 years	B-cell and T-cell characteristics in former mpox patients and smallpox vaccinees 8, 16, 24 months after symptom

Trial Locations

Locations (1)

Institute of Tropical Medicine; 🇧🇪 Antwerp, Belgium