Study on the Persistence of Immunity Following EV71 Vaccination

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.

NCT Number	NCT07144202
Lead Sponsor	Institute of Medical Biology, Chinese Academy of Medical Sciences
Conditions	Hand, Foot, and Mouth Disease, Hand, Foot, and Mouth Disease (HFMD)
Enrollment	270 participants
Start Date	2025-08-10
Primary Completion	2025-08-25 (estimated)
Study Completion	2026-03-10 (estimated)
Updated on ClinicalTrials.gov	2025-08-27