Immunogenicity of an Inactivated COVID-19 Vaccine

Study Overview
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Brief Summary
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This study is an open phase 4 clinical trial of an inactivated COVID-19 vaccine (CoronaVac) manufactured by Sinovac Research and Development Co., Ltd. The purpose of this study is to evaluate the immunogenicity of the CoronaVac in healthy children aged 3-11 years old.

Detailed Description
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This study is an open phase 4 clinical trial to evaluate the immunogenicity of an inactivated COVID-19 vaccine(CoronaVac)in healthy children aged 3-11 years old.A total of 400 healthy subjects who have received two doses of inactivated COVID-19 vaccine(CoronaVac) manufactured by Sinovac Research & Development Co., Ltd and is currently 28-42 days after the second dose will be enrolled, including 200 subjects aged 3-5 years and 200 subjects aged 6-11 years old.All of subjects will be collected 3ml venous blood to evaluate the immunogenicity of the CoronaVac.

Official Title
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Immunogenicity of an Inactivated COVID-19 Vaccine for Prevention of COVID-19 in Population Aged 3-11 Years

Conditions
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COVID-19

Intervention / Treatment
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* Biological: Inactivated COVID-19 Vaccine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Have received two doses of inactivated COVID-19 vaccine(CoronaVac) manufactured by Sinovac Research & Development Co., Ltd and is currently 28-42 days after the second dose; The subjects and/or guardians can understand and voluntarily sign the informed consent form (for subjects aged 8 years, both subjects and guardians need to sign the informed consent form); The subjects and their legal guardians voluntarily participate the study and comply with the study procedure to collect 3ml venous blood; Proven legal identity. Exclusion Criteria: Haven't received two doses of inactivated COVID-19 vaccine(CoronaVac); Have received COVID-19 vaccines from other manufacturers; The interval between blood collection and the second dose is less than 28 days or more than 42 days; The subjets and their legal guardians can't cooperate to complete 3ml venous blood collection. 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: 3 Years
Maximum Age: 11 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: Experimental Group of children aged 3-5 years old<br>200 subjects aged 3-5 years old who have received two doses of inactivated COVID-19 vaccine(CoronaVac) manufactured by Sinovac Research & Development Co., Ltd and is currently 28-42 days after the second dose | Biological: Inactivated COVID-19 Vaccine<br>* 600SU inactivated virus in 0.5 mL of aluminium hydroxide solution per injection<br>* Other names: CoronaVac;|
| Experimental: Experimental Group of children aged 6-11 years old<br>200 subjects aged 6-11 years old who have received two doses of inactivated COVID-19 vaccine(CoronaVac) manufactured by Sinovac Research & Development Co., Ltd and is currently 28-42 days after the second dose | Biological: Inactivated COVID-19 Vaccine<br>* 600SU inactivated virus in 0.5 mL of aluminium hydroxide solution per injection<br>* Other names: CoronaVac;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Immunogenicity index-Seropositivity rate of the neutralizing antibody to SARS-CoV-2 | Seropositivity rate of the neutralizing antibody day 28(+14 days) after the second dose of vaccine | Day 28(+14 days) after the second dose of vaccine | 
| Immunogenicity index-GMT of the neutralizing antibody to SARS-CoV-2 | GMT of the neutralizing antibody to SARS-CoV-2 day 28(+14 days) after the second dose of vaccine | Day 28(+14 days) after the second dose of vaccine |