An observational study in Hand, Foot, and Mouth Disease and Hand, Foot, and Mouth Disease (HFMD), sponsored by Institute of Medical Biology, Chinese Academy of Medical Sciences. Enrolling by invitation at 4 sites in China. Per ClinicalTrials.gov, last updated 2025-08-27.
Sponsored by Institute of Medical Biology, Chinese Academy of Medical Sciences · Observational
This is a thirteen-year follow-up study conducted as an extension of a Phase III clinical trial. In this study, a sub-cohort of volunteers who was eligible for enrollment and randomly administrated either 2 dose EV71 vaccine or placebo in the phase III clinical trial was selected to evaluate the EV71 immune levels 13 years after the primary vaccination.
The initial study was a randomized, double-blind, placebo-controlled phase III clinical trial conducted in children aged 6-71 months from Guilin region of Guangxi Province in 2012. A total of 12000 participants (with 1100 in the immunogenicity group) were randomized in a 1:1 ratio to receive two doses EV71 vaccine or placebo on a 0-, 28-day schedule. Besides, an extended one-year and two year follow-up of this study was completed in 2013.
In this study, immunogenicity group participants from the phase III clinical trial was chosen as the studied subjects. A retrospective survey for the enrolled subjects involved with the history of HFMD and the extra vaccination of EV71 vaccine was conducted before blood collection. 3 ml venous blood were collected from each available subject for EV71 neutralizing antibody (NAb) testing. Since the unblinding was performed after the initial study completed, this study was an open-labelled detection for the persistence of the vaccine-induced EV71 NAb.
59 studies on the registry are indexed under Hand, Foot and Mouth Disease; 10 are open to participants now.
Browse Hand, Foot and Mouth Disease studies →Institute of Medical Biology, Chinese Academy of Medical Sciences is the lead sponsor of 29 studies on the registry; 10 are open to participants now.
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Immunogenicity group participants from the phase III clinical trial
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Exclusion Criteria:
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Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Two doses of placebo at the vaccination schedule of Day 0, 28
EV71 vaccine on Day 0, 28
Immunogenicity index-seropositive rates of neutralizing antibody
Neutralizing antibody assay will be performed using the neutralization and Microneutralization test method. Seropositive will be defined as the positive results with ties≥1:8
Time frame: Year 13 after the second vaccination
Immunogenicity index-geometric mean titer (GMT) of neutralizing antibody
Neutralizing antibody assay will be performed using the neutralization and Microneutralization test method
Time frame: Year 13 after the second vaccination
Plan to share: No
No publications or documents are linked to this record.
Started Aug 2025 (actual). Primary completion is estimated for Aug 2025, 0 months after the start.
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Hand, Foot and Mouth Disease →
Institute of Medical Biology, Chinese Academy of Medical Sciences