Study on the Persistence of Immunity Following EV71 Vaccination

NCT07144202 | Enrolling By Invitation

• 1 other identifier: EV71-402
• Study Type: observational
• Target: 270
• Locations: 1 country
• Sites: 4

Brief Summary

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.

Conditions

Hand, Foot, and Mouth Disease; Hand, Foot, and Mouth Disease (HFMD)

Outcome Measures

Primary Outcomes (2)

• 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

  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

  Year 13 after the second vaccination

Study Arms (2)

Placebo

Two doses of placebo at the vaccination schedule of Day 0, 28

Vaccine

EV71 vaccine on Day 0, 28

Eligibility Criteria

• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Immunogenicity group participants from the phase III clinical trial

You may qualify if:

• Included in the immunogenicity group of initial studyand randomly into either vaccine (fulfilled the two doses vaccination following the protocol) or placebo group.
• Volunteers and their legal guardians or appointed representatives must provide valid legal identification documents.
• Legal guardians or appointed representatives of volunteers must have the capacity to understand the informed consent document and the research process, voluntarily participate, sign the informed consent form, and be able to comply with the study's requirements.

You may not qualify if:

• Had history of extra EV71 vaccination.
• Previous history of hand-foot-mouth disease.
• Participating in other research.
• Subjects with a hereditary bleeding tendency or coagulopathy, or a history of bleeding disorders.

Sponsors & Collaborators

• Institute of Medical Biology, Chinese Academy of Medical Sciences: lead

Study Sites (4)

Lingchuan Center for Disease Control and Prevention

Guilin, Guangxi, China

Location

Lipu Center for Disease Control and Prevention

Guilin, Guangxi, China

Location

Xing'an Center for Disease Control and Prevention

Guilin, Guangxi, China

Location

Yongfu Center for Disease Control and Prevention

Guilin, Guangxi, China

Location

Biospecimen

Retention: SAMPLES WITHOUT DNA

venous blood

MeSH Terms

Conditions

Hand, Foot and Mouth Disease

Condition Hierarchy (Ancestors)

Coxsackievirus Infections; Enterovirus Infections; Picornaviridae Infections; RNA Virus Infections; Virus Diseases; Infections

Study Officials

• Teng Huang

  Guangxi Zhuang Autonomous Region Center for Disease Prevention and Control

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 20, 2025
• First Posted: August 27, 2025
• Study Start: August 10, 2025
• Primary Completion: August 25, 2025
• Study Completion: March 10, 2026
• Last Updated: August 27, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will not share

Locations

CN (4)