NCT07144202

Study on the Persistence of Immunity Following EV71 Vaccination

Study on the Immunity Persistence Following Immunization With Enterovirus Type 71 Vaccine, Inactivated (Human Diploid Cell)

• Status: Enrolling By Invitation
• Phase: —
• Study type: Observational
• Enrollment: 270 (estimated)
• Sponsor: Institute of Medical Biology, Chinese Academy of Medical Sciences · Academic / Other
• Sex: All
• Age: —
• Healthy volunteers: Accepted

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.

Detailed description

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.

Conditions

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

Timeline

• Start date: 2025-08-10
• Primary completion: 2025-08-25
• Completion: 2026-03-10
• First posted: 2025-08-27
• Last updated: 2025-08-27

Locations

4 sites across 1 country: China