Actively Recruiting
Prospective Study for the Follow-Up of Mpox Patients and Smallpox Vaccinees Evaluating Long-Term Immunity and Post-Infection Effects
Led by Institute of Tropical Medicine, Belgium · Updated on 2026-03-19
345
Participants Needed
1
Research Sites
34 weeks
Total Duration
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AI-Summary
What this Trial Is About
Researchers are investigating the long-term physical and psychological effects following mpox infection and the duration of immune responses in people who had mpox or received smallpox vaccines. This observational study aims to understand whether mpox patients experience lasting symptoms, how durable their B- and T-cell immune responses are, and whether local immunity differs from systemic immunity. It also evaluates how long the virus remains detectable in fluids such as semen, saliva, and the ano-rectal region. Participants include those with confirmed mpox infection, individuals vaccinated with two doses of third-generation smallpox vaccines (either intradermal or subcutaneous), and healthy controls without prior mpox infection or vaccination. The study collects various samples including blood, saliva, anal swabs, and optional semen samples. Follow-up visits are scheduled at 8, 16, 24, 36, 48, and 60 months after infection or vaccination to monitor immune responses and any lasting symptoms. During the study, participants will complete questionnaires and provide biological samples for laboratory analysis, including PCR tests and immune cell profiling. Researchers will measure the proportion of individuals with positive mpox serology and document any long-term problems over two years. The study also tracks the longevity of immune responses to mpox and vaccinia virus. Participants' adherence to the schedule and consent are required for ongoing follow-up and sample collection.
CONDITIONS
Brief Title
Prospective Study for the FOLLOW-UP of Human Monkeypox Cases and Smallpox Vaccinees at Risk
Who Can Participate
Eligibility Criteria
You may qualify if you...
- PCR-confirmed mpox infection since May 2022 (for mpox patients)
- At least 18 years old
- Willing to provide written informed consent
- Willing to follow the study schedule
- At least two smallpox vaccinations (for vaccinees)
- On HIV-PrEP and a patient from ITM (for controls)
You will not qualify if you...
- Any vaccination 2 weeks before or after study visits (4 weeks for live vaccines)
- Use of immune-compromising drugs or presence of immune-compromising diseases (except treated and controlled HIV infection)
- Any mpox reinfection since study start (for mpox patients)
- Any mpox infection in the past (for vaccinees and controls)
- Born before 1976 (for controls)
- Any documented or remembered smallpox vaccination or typical scar (for controls)
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - Up to 24 months
Participants are followed up over time to evaluate long-term symptoms, sequelae, and immune responses after mpox infection or smallpox vaccination.
Visits at 8, 16, and 24 months after infection or vaccination
Trial Site Locations
Total: 1 location
1
Institute of Tropical Medicine
Antwerp, Belgium, 2000
Actively Recruiting
Research Team
S
Study Coordinator
How is the study designed?
Study Type
OBSERVATIONAL
Masking
N/A
Allocation
N/A
Model
N/A
Primary Purpose
N/A
Number of Arms
3
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