This study is a randomized, placebo-controlled and opened, phase 4 clinical trial to evaluate the safety and immunogenicity of an inactivated COVID-19 vaccine(CoronaVac）in healthy population aged 18 years and older . The experimental vaccine is manufactured by Sinovac Research and Development Co.,Ltd. A total of 270 healthy subjects will be enrolled, including 135 adults aged 18-59 years and 135 elderly elderly aged 60 years and older. Subjects in each age group will be divided into two groups in a ratio of 1:1. Subjects in the experimental group will receive two doses of CoronaVac on day 0 and day 28. Subjects in the control group will receive one dose of 23-valent Pneumococcal Polysaccharide Vaccine on day 0 and one dose of Inactivated Hepatitis A Vaccine on day 28.
This study is a randomized, placebo-controlled and open design, 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 and safety of the CoronaVac in healthy population aged 18 years and older.