An Open-labelled Clinical Trial of Live Attenuated Varicella Vaccines to Evaluate the Immunity Persistence After Primary Immunization and Safety and Immunogenicity After the Booster Immunization

Study Overview
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Brief Summary
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This is an open-labelled 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 the single-dose primary immunization of live attenuated varicella vaccine on different time points ,and the safety and immunogenicity after the booster immunization

Detailed Description
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This study is an open-labelled phase Ⅲ clinical trial.The experimental vaccine manufactured by Sinovac(Dalian) Vaccine Technology Co., Ltd.A total of 1195 subjects who received vaccine in the phase Ⅲ lot-consistency clinical trial were be enrolled .All subjects except C0243 and C0556 were divided into 3 groups according to the order of study number.Subjects in 3 groups received a booster immunization of live attenuated varicella vaccines 1 year,2 years and 3 years after primary immunization,respectively.About 3.0ml of venous blood was collected from each enrolled subject at pre-booster immunization,30 days after booster immunization and the serum was separated for neutralizing antibody detection.The antibody levels were used to evaluate the immunity persistence and immunogenicity after booster immunization of live attenuated varicella vaccines .

Official Title
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An Open-labelled Clinical Trial,to Evaluate the Immunity Persistence of the Single-dose Primary Immunization of Live Attenuated Varicella Vaccine on Different Time Points,and the Safety and Immunogenicity After the Booster Immunization

Conditions
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Varicella

Intervention / Treatment
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* Biological: Investigational live attenuated varicella vaccine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Received one dose live attenuated varicella vaccine in the phase Ⅲ lot-consistency clinical trial; Guardian(s) of the volunteer should be capable of understanding the written - consent form, and such form should be signed before the children being included into this study. Exclusion Criteria: Received one dose live attenuated varicella vaccine at the end of the phase Ⅲ lot-consistency clinical trial; According to the investigator's judgment, the subject has any other factors that are not suitable for participating in the clinical trial.

Ages Eligible for Study
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Minimum Age: 2 Years
Maximum Age: 6 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Booster immunization 1 year after primary immunization<br>Subjects C0001-C0400 except C0243 received 1 dose of booster immunization 1 year after primary immunization. | Biological: Investigational live attenuated varicella vaccine<br>* The investigational vaccine was manufactured by Sinovac (Dalian) Vaccine Technology Co., Ltd.And the live varicella-zoster virus in 0·5 mL of sucrose, sodium glutamate,sodium chloride,potassium chloride,sodium dihydrogen phosphate, potassium dihydrogen phosphate and injection water per injection<br>|
| Experimental: Booster immunization 2 year after primary immunization<br>Subjects C0401-C0800 except C0556 received 1 dose of booster immunization 2 years after primary immunization. | Biological: Investigational live attenuated varicella vaccine<br>* The investigational vaccine was manufactured by Sinovac (Dalian) Vaccine Technology Co., Ltd.And the live varicella-zoster virus in 0·5 mL of sucrose, sodium glutamate,sodium chloride,potassium chloride,sodium dihydrogen phosphate, potassium dihydrogen phosphate and injection water per injection<br>|
| Experimental: Booster immunization 3 year after primary immunization<br>Subjects C0801-C1197 received 1 dose of booster immunization 3 years after primary immunization. | Biological: Investigational live attenuated varicella vaccine<br>* The investigational vaccine was manufactured by Sinovac (Dalian) Vaccine Technology Co., Ltd.And the live varicella-zoster virus in 0·5 mL of sucrose, sodium glutamate,sodium chloride,potassium chloride,sodium dihydrogen phosphate, potassium dihydrogen phosphate and injection water per injection<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Immunogenicity index-seroconversion rate of antibody | seroconversion rates of antibody 1 year after primary immunization | 1 year after primary immunization | 
| Immunogenicity index-seroconversion rate of antibody | seroconversion rates of antibody 2 years after primary immunization | 2 years after primary immunization | 
| Immunogenicity index-seroconversion rate of antibody | seroconversion rates of antibody 3 years after primary immunization | 3 years after primary immunization | 
| Immunogenicity index-Seroconversion rate of antibody | Seroconversion rate of the neutralizing antibody 30 days after booster immunization | 30 days after booster immunization | 
| Immunogenicity index-seropositivity rate of antibody | Seropositivity rate of antibody 30 days after booster immunization | 30 days after booster immunization | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Immunogenicity index-Seropositivity rate of antibody | Seropositivity rate of antibody before booster immunization | Before the booster dose immunization | 
| Immunogenicity index-GMT of the antibody | GMT of the antibody before booster immunization | Before the booster dose immunization | 
| Immunogenicity index- GMT of the antibody | GMT of the antibody 30 days after booster immunization | 30 days after booster immunization | 
| Immunogenicity index- GMI of the antibody | GMI of the antibody 30 days after booster immunization | 30 days after booster immunization | 
| Safety index-Incidence of solicited local or systemic AE | Incidence of solicited local or systemic AE within 14 days after vaccination | within 14 days after vaccination | 
| Safety index-Incidence of local or systemic AE | Incidence of local or systemic AE within 30 days after vaccination | within 30 days after vaccination | 
| Safety index-Incidence of SAE | Incidence of SAE within 30 days after vaccination | within 30 days after vaccination |