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.
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.