Clinical trial NCT05397587: An Immunity Persistence Study of Enterovirus 71 Inactivated Vaccine (Vero Cell)
Official title: An Open, Observational Study to Evaluate the Immunity Persistence of an Inactivated Enterovirus 71 Vaccine (Vero Cell) in Subjects Aged 6 to 71 Months
Study type: INTERVENTIONAL
Overall status: NOT_YET_RECRUITING
Phase: PHASE4
Conditions: Hand, Foot and Mouth Disease
Lead sponsor: Sinovac Biotech Co., Ltd
Sponsor class: INDUSTRY
First posted: 2022-05-31
Enrollment: 474
Sex: ALL
Minimum age (years): 6
Maximum age (years): 71
Standard ages: CHILD
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief 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.

Detailed description: This study is an open,observational and follow-up clinical trial of EV71 vaccine based on the clinical trial of EV71 vaccine extended age group.The main 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.In this study, a total of 474 subjects from the EV71 vaccine extended age clinical trial who received two doses of experimental or control vaccine and were enrolled in the PPS set，including 274 subjects aged 6\~35 months (the maximum number of subjects aged 6-23 months is 146, and the maximum number of subjects aged 24-35 months is 128),100 subjects aged 36\~71 months and were enrolled in experimental group(EV71 vaccine developed by Sinovac Biotech Co., Ltd) and 100 subjects aged 36\~71 months and were enrolled in control group(EV71 vaccine developed by Institute of Medical Biology,Chinese Academy of Medical Sciences) will be enrolled .Blood samples will be collected from subjects aged 6-23 months at 36 months after full immunization and at the age of 72 months.Blood samples will be collected from subjects aged 24 to 35 months at 36 months after full immunization.Blood samples will be collected from subjects aged 36-71 months at 36 months after the full immunization.

Eligibility criteria: 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.

Primary outcomes:
measure: The seroconversion rates (SCR) of EV71 neutralizing antibody of all enrolled subjects
timeFrame: At 36 months after full immunization
measure: The seroconversion rates (SCR) of the EV71 neutralizing antibody of subjects aged 6-23 months
timeFrame: At the age of 72 months
measure: GMT of the EV71 neutralizing antibody of all enrolled subjects
timeFrame: At 36 months after full immunization
measure: GMT of the EV71 neutralizing antibody of subjects aged 6-23 months
timeFrame: At the age of 72 months
Secondary outcomes:
Other outcomes:
Locations:
city: Lincang
country: China
facility: Yun County Center for Disease Control and Prevention
state: Yunnan
Study officials:
affiliation: Yunnan Provincial Center for Disease Control and Prevention
name: Yan Zheng, Master
role: PRINCIPAL_INVESTIGATOR
References: