Clinical trial NCT03281174: Five-year Immune Persistence Study of Inactivated Enterovirus Type 71 (EV71) Vaccine
Official title: Phase IV, Open-labelled, Five-year Immune Persistence Study of Inactivated Enterovirus Type 71 (EV71) Vaccine
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Hand, Foot and Mouth Disease
Keywords: Inactivated Enterovirus Type 71 (EV71) Vaccine
5-year Immune Persistence
Lead sponsor: Sinovac Biotech Co., Ltd
Sponsor class: INDUSTRY
First posted: 2017-09-13
Enrollment: 343
Sex: ALL
Minimum age (years): 6
Maximum age (years): 35
Standard ages: CHILD
Accepts healthy volunteers: yes
Observational model: OTHER
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: The studied subjects are infants aged 6-35 months old infants when enrolled into the phase III clinical trial, and they are children aged 6-8 years old five years after the EV71 vaccine /placebo injection.

Brief summary: The purpose of this study is to evaluate the 5-year Immune Persistence of Inactivated Enterovirus Type 71 (EV71) Vaccine manufactured by Sinovac (Beijing) Biotech Co., Ltd.

Detailed description: The phase III, efficacy trial of inactivated vaccine (vero cell) against EV71 has completed on March 2013 in China,and a follow up study for phase III clinical trial has completed on March 2014.

On the basis of phase III, this study is the Phase IV, open-labelled research, in order to evaluate the 5-year immune persistence of EV71 vaccine.

Eligibility criteria: Inclusion Criteria:

In the prior phase III clinical trial, 10077 subjects in three counties (Ganyu, Sheyang and Taixing ) were enrolled ( Experimental group: 5044; Control group: 5043 ), with 1293 of them in immunogenicity subgroup (Experimental group: 648; Control group: 645). In Sheyang county, 3351 subjects were enrolled (Experimental group: 1676 ; Control group :1675) , with 435 of them in immunogenicity subgroup (Experimental group: 418 ; Control group :418).

The subjects in Sheyang immunogenicity subgroup with the following conditions were included in this study:

* Guardian(s) of the volunteer should be capable of understanding the written consent form, and such form should be signed before the infant being included into this study
* Received at least one injection of EV71 vaccine or the placebo in the phase III clinical trial
* Finished the blood sampling 64 months after the vaccination

Exclusion Criteria:

* Received extra EV71 vaccination after the phase III clinical trial
* Refused to join the study

Primary outcomes:
measure: The seropositive rate of EV71 neutralizing antibody-1
timeFrame: 5 years (64 months)
Secondary outcomes:
measure: The seropositive rate of EV71 neutralizing antibody-2
timeFrame: 5 years (64 months)
measure: The seropositive rate of EV71 neutralizing antibody-3
timeFrame: 5 years (64 months)
measure: The GMT of EV71 neutralizing antibody
timeFrame: 5 years (64 months)
Other outcomes:
Locations:
city: Yancheng
country: China
facility: Sheyang Center for Disease Control and Prevention
state: Jiangsu
Study officials:
affiliation: Jiangsu Provicial Center for Disease Control and Prevention
name: Yuemei Hu
role: PRINCIPAL_INVESTIGATOR
References:
citation: Hu Y, Zeng G, Chu K, Zhang J, Han W, Zhang Y, Li J, Zhu F. Five-year immunity persistence following immunization with inactivated enterovirus 71 type (EV71) vaccine in healthy children: A further observation. Hum Vaccin Immunother. 2018 Jun 3;14(6):1517-1523. doi: 10.1080/21645515.2018.1442997. Epub 2018 Apr 11.