RecruitingPhase 4

Smallpox Vaccine for Mpox Post-Exposure Prophylaxis: A Cluster RCT

Democratic Republic of the Congo, Nigeria, Uganda3,000 participantsStarted 2024-09-17

Plain-language summary

A cluster randomized controlled trial to determine if smallpox vaccine reduces secondary cases and symptom severity in persons exposed to mpox.

Who can participate

Age range

2 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion criteria

. Household member of person with laboratory confirmed mpox
. Age ≥ 2 years
. Within 14 days of onset of illness in mpox index case

Exclusion criteria

. Pregnancy
. Breastfeeding
. Past serious allergic reaction to study vaccine components
. Previous smallpox vaccination
. Current or planned use of another investigational drug at any point during study participation

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

PCR-confirmed Mpox

Timeframe: 8 weeks

Symptom severity

Timeframe: 8 weeks

Trial details

NCT IDNCT05745987

SponsorMcMaster University

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2026-06-01

Contact for this trial

Mark Loeb, MD

9055259140 loebm@mcmaster.ca

View on ClinicalTrials.gov More Monkeypox trials