Active — Not RecruitingNot Applicable

Long-Term Immunogenicity of Envacgen® in Children

Taiwan220 participantsStarted 2025-11-24

Plain-language summary

This study is designed to evaluate the long-term antibody titers of Envacgen® approximately 6 years after the first vaccination dose in participants who were aged 2 months to \<6 years at the time of enrollment in the CT-EV-31s study.

Who can participate

Age range

6 Years – 13 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: * Participants who have completed participation in study CT-EV-31s and have received protocol specified doses of EV71 vaccine or Placebo. * The participant and/or participant's parent/guardian is able to understand and sign the informed consent form. Exclusion Criteria: * The participant and/or participant's parent/guardian refuse to comply with the study procedures. * After completing the CT-EV-31s trial, participants who received any EV71 vaccine before participating in this study.

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

Serum neutralizing antibody titer

Timeframe: Approximately 6 years after first dose of vaccination.

Seroprotection rate

Timeframe: Approximately 6 years after first dose of vaccination

Trial details

NCT IDNCT07568522

SponsorMedigen Vaccine Biologics Corp.

Sponsor typeINDUSTRY

Study typeOBSERVATIONAL

Primary completion2026-02-16

View on ClinicalTrials.gov More Enterovirus 71 Human trials

Who can participate

Age range

6 Years – 13 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.