UnknownPhase 4

An Immunity Persistence Study of Enterovirus 71 Inactivated Vaccine (Vero Cell)

China474 participantsStarted 2022-07-30

Plain-language summary

This is an open，observational and follow-up clinical trial based on the clinical trial of EV71 vaccine extended age group.The purpose of this study is to evaluate the immunity persistence of EV71 vaccine developed by Sinovac Biotech Co., Ltd in subjects aged 6 \~71 months after full immunization of two doses of vaccine.

Who can participate

Age range

6 Months – 71 Months

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: * Subjects in the EV71 vaccine extended age clinical trial who received two doses of experimental or control vaccine and were enrolled in the PPS set; * Provide legal identification; * Participants or guardians of the participants should be capable of understanding the written consent form and voluntarily participate in the clinical trial. Exclusion Criteria: * Vaccination history of vaccines containing EV71 antigen components other than the EV71 vaccine expanded age group clinical trial; * History of hand, foot and mouth disease caused EV71; * According to the investigator's judgment, the subject has any other factors that are not suitable for participating in the clinical trial.

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

The seroconversion rates (SCR) of EV71 neutralizing antibody of all enrolled subjects

Timeframe: At 36 months after full immunization

The seroconversion rates (SCR) of the EV71 neutralizing antibody of subjects aged 6-23 months

Timeframe: At the age of 72 months

GMT of the EV71 neutralizing antibody of all enrolled subjects

Timeframe: At 36 months after full immunization

GMT of the EV71 neutralizing antibody of subjects aged 6-23 months

Timeframe: At the age of 72 months

Trial details

NCT IDNCT05397587

SponsorSinovac Biotech Co., Ltd

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2025-07-30

Contact for this trial

Yan Zheng, Master

18987115640 yaqueer_zy@163.com

View on ClinicalTrials.gov More Hand, Foot and Mouth Disease trials

Plain-language summary

Who can participate

Age range

6 Months – 71 Months

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.

What they're measuring

The seroconversion rates (SCR) of EV71 neutralizing antibody of all enrolled subjects

Timeframe: At 36 months after full immunization

The seroconversion rates (SCR) of the EV71 neutralizing antibody of subjects aged 6-23 months

Timeframe: At the age of 72 months

GMT of the EV71 neutralizing antibody of all enrolled subjects

Timeframe: At 36 months after full immunization

GMT of the EV71 neutralizing antibody of subjects aged 6-23 months

Timeframe: At the age of 72 months