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

NCT05879965 | Recruiting DMC

• 1 other identifier: 1628/22
• Study Type: observational
• Target: 345
• Locations: 1 country
• Sites: 1

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.

Conditions

Monkeypox

Keywords

mpox; immunology; mucosal immunity; sequelae; smallpox vaccination

Outcome Measures

Primary Outcomes (2)

• Proportion of individuals with a positive mpox serology in both groups

  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

  2 years

• Proportion of long-term problems or sequelae in mpox patients

  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

  2 years

Secondary Outcomes (1)

• longevity of humoral and/or cellular immune response to mpox or vaccinia virus

  2 years

Study Arms (3)

mpox patients

mpox cohort diagnosed and confirmed by PCR at the Institute of Tropical Medicine (ITM) in Antwerp during the recent mpox outbreak May-October 2022, 95 consented patients for follow-up

Smallpox vaccine recipients

sub-group 1: 100 participants routinely vaccinated with two subcutaneous 3rd generation smallpox vaccines sub-group 2: 100 participants routinely vaccinated with two intradermal 3rd generation smallpox vaccines

Healthy controls

50 controls recruited during HIV-PrEP consultation (no former mpox infection, no smallpox vaccination)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Former mpox patients ≥18 years, diagnosed by PCR at ITM since May 2022 Smallpox vaccine recipients vaccinated at ITM since August 2022 Healthy HIV-PrEP users

You may qualify if:

• PCR-confirmed mpox infection since May 2022
• ≥18 years
• Willingness to provide written informed consent
• Willingness to follow the study schedule

You may not qualify if:

• Any vaccination 2 weeks before or after the visits (4 weeks for life-vaccines)
• Any mpox reinfection since study start
• Smallpox vaccinees for immunological study
• At least two smallpox vaccinations.
• ≥18 years
• Willingness to provide written informed consent
• Willingness to follow the study schedule
• Any vaccination 2 weeks before or after the visits (4 weeks for life-vaccines)
• Any mpox infection in the past
• HIV-Prep patients
• On HIV-PrEP and a patient from ITM
• ≥18 years
• Willingness to provide written informed consent
• Willingness to follow the study schedule
• Born before 1976

Sponsors & Collaborators

• Institute of Tropical Medicine, Belgium: lead

Study Sites (1)

Institute of Tropical Medicine

Antwerp, 2000, Belgium

RECRUITING

Biospecimen

Retention: SAMPLES WITH DNA

Serum, PBMC, saliva, semen, anal swab

MeSH Terms

Conditions

Mpox, Monkeypox

Condition Hierarchy (Ancestors)

Poxviridae Infections; DNA Virus Infections; Virus Diseases; Infections; Primate Diseases; Animal Diseases; Rodent Diseases

Study Officials

• Nicole Berens-Riha, PhD

  Institute of Tropical Medicine

  PRINCIPAL INVESTIGATOR

• Laurens Liesenborghs, PhD

  Institute of Tropical Medicine

  STUDY DIRECTOR

Central Study Contacts

Study Coordinator

CONTACT

+32(0)33455672; bsmekens@itg.be

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 19, 2023
• First Posted: May 30, 2023
• Study Start: October 6, 2022
• Primary Completion (Estimated): October 1, 2027
• Study Completion (Estimated): June 1, 2028
• Last Updated: March 19, 2026

Record last verified: 2026-03

Locations

BE (1)