Follow-up of monkeypox cases and smallpox vaccine recipients
Official title: 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
Run by Institute of Tropical Medicine, Belgium · NCT05879965 · Data updated 2026-11-12
This project will follow adults who had monkeypox and people who received smallpox vaccine doses to see if immune responses remain strong over time and if any lasting physical or psychological effects develop.
Quick facts
| Study type | Observational |
|---|---|
| Ages | 18 Years and up |
| Sex | All |
| Enrollment | 345 (estimated) |
| Sponsor | Institute of Tropical Medicine, Belgium Academic / other |
| Locations | 1 site (Antwerp) |
| Status | Recruiting |
| Started | October 6, 2022 |
| Main results expected | October 2027 |
| Study ends | June 2028 |
| Registry record updated | March 19, 2026 |
| Trial ID | NCT05879965 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Ideal participants are adults (≥18) who are PCR-confirmed monkeypox survivors since May 2022, adults with at least two prior smallpox vaccinations, or HIV-PrEP clinic patients willing to attend follow-up visits and provide biological samples.
✕Probably not a fit
People who recently received other vaccinations, have active immunocompromising conditions or treatments (except treated and controlled HIV), are unwilling to provide the requested samples, or who experienced mpox reinfection since enrollment may not gain useful information from participation.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
This prospective longitudinal observational study follows PCR-confirmed monkeypox patients, people who received two smallpox vaccine doses, and unvaccinated controls from an HIV-PrEP clinic for up to five years. Participants complete questionnaires and provide blood, saliva, anal swabs, and optional semen samples at baseline and scheduled follow-ups at 8, 16, 24, 36, 48, and 60 months. Laboratory analysis includes MPXV PCR on mucosal samples and measurement of B- and T-cell responses, with PBMCs collected from a subgroup for cellular assays. The study compares local (mucosal) versus systemic immunity and documents any physical or psychological sequelae over time.
Why it matters
Potential benefit: If successful, the project could clarify how long immunity from infection or vaccination lasts and identify patients who need ongoing monitoring or care for long-term effects.
How similar studies have gone: Prior studies have documented short-term immune responses and viral shedding after mpox, but few have provided the multi-year immunologic follow-up and systematic sequelae data this study aims to collect.
Who can join: the full rules
Show full inclusion / exclusion 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 exclusion criteria) * Any mpox reinfection since study start Smallpox vaccinees for immunological study Inclusion criteria * At least two smallpox vaccinations. * ≥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 exclusion criteria) * Any mpox infection in the past HIV-Prep patients Inclusion criteria * On HIV-PrEP and a patient from ITM * ≥18 years * Willingness to provide written informed consent * Willingness to follow the study schedule Exclusion criteria * Born before 1976 * Any documented or remembered smallpox vaccination or typical scar for a smallpox vaccination * Any vaccination 2 weeks before or after the visits (4 weeks for life-vaccines) * Any immune-compromising drugs or diseases * Any mpox infection in the past
Where it's running
-
Institute of Tropical Medicine
Antwerp, Belgium Recruiting
Study contacts
- Principal investigator: Nicole Berens-Riha, PhD — Institute of Tropical Medicine
- Study coordinator: Study Coordinator
- Email: bsmekens@itg.be
- Phone: +32(0)33455672
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How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.