This study is a randomized, double-blinded, placebo-controlled,phase Ⅱb clinical trial in children and adolescents aged 3-17 years. The experimental vaccine and placebo were both manufactured by Sinovac Life Sciences Co. , Ltd. A total of 500 subjects will be enrolled, including 100 children aged 3-5 years, 200 children aged 6-11 years and 200 adolescents aged 12-17 years. Each age group will be randomly divided into two groups in a 3:1 ratio and received two doses of experimental vaccine or placebo on on day 0 and day 28.
This study is a randomized, double-blinded, placebo-controlled, phase Ⅱb clinical trial of an inactivated SARS-CoV-2 vaccine (CoronaVac) manufactured by Sinovac Life Sciences Co. , Ltd.The purpose of this study is to evaluate the safety of the SARS-CoV-2 Inactivated vaccine in healthy children and adolescents aged 3-17 years.