Clinical trial NCT05095701: An Immunity Persistence Study of Live Attenuated Varicella Vaccine
Official title: An Open Clinical Trial to Evaluate the Immunity Persistence of Live Attenuated Varicella Vaccine At 5 and 8 Years After Primary Immunization with Live Attenuated Varicella Vaccine
Study type: INTERVENTIONAL
Overall status: ENROLLING_BY_INVITATION
Phase: PHASE4
Conditions: Varicella
Lead sponsor: Sinovac (Dalian) Vaccine Technology Co., Ltd.
Sponsor class: INDUSTRY
First posted: 2021-10-27
Enrollment: 703
Sex: ALL
Minimum age (years): 1
Maximum age (years): 17
Standard ages: CHILD
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: This an open phase Ⅳ clinical trial of live attenuated varicella vaccines manufactured by Sinovac (Dalian) Vaccine Technology Co., Ltd .The purpose of this study is to evaluate the immunity persistence of live attenuated varicella vaccine at 5 and 8 years after primary immunization with live attenuated varicella vaccine.

Detailed description: This study is an open phase Ⅳ clinical trial in subjects who enrolled in the clinical trial and included in the immunogenicity subgroup PPS set from August to September 2016 .The experimental vaccine and placebo (Freeze Dired Dilution) were manufactured by Sinovac (Dalian) Vaccine Technology Co., Ltd.A total of 703 subjects will be enrolled including 349 subjects in experimental group and 354 subjects in control group .And 3.0-3.5ml of venous blood was collected from all subjects at 5 and 8 years after primary immunization, and the serum was separated for varicella antibody detection. The window period of blood collection was six months.

Eligibility criteria: Inclusion Criteria:

* Subjects in PPS immunogenicity subgroup of phase Ⅲ clinical trial of protective effect of varicella vaccine;
* The subject and/or guardian can understand and voluntarily sign the informed consent form;
* Proven legal identity.

Exclusion Criteria:

* History of chickenpox or shingles;
* History of varicella vaccination since phase Ⅲ clinical trial;
* Autoimmune disease or immunodeficiency / immunosuppression;
* History of immunosuppressive therapy since phase Ⅲ clinical trial;
* 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: Immunogenicity index-seropositive rates of varicella antibody
timeFrame: 5 years after primary immunization
measure: Immunogenicity index-GMT of varicella antibody
timeFrame: 5 years after primary immunization
measure: Immunogenicity index-the seropositive rates of varicella antibody
timeFrame: 8 years after primary immunization
measure: Immunogenicity index-the GMT of varicella antibody
timeFrame: 8 years after primary immunization
Secondary outcomes:
Other outcomes:
Locations:
city: Xuchang
country: China
facility: Xiangcheng County Center for Disease Control and Prevention
state: Henan
city: Zhumadian
country: China
facility: Biyang County Center for Disease Control and Prevention
state: Henan
Study officials:
affiliation: Henan Provincial Center for Disease Prevention and Control
name: Lili Huang, Bachelor
role: PRINCIPAL_INVESTIGATOR
References: