A PhaseⅡ Study to Evaluate the Safety and Immunogenicity of COVID-19 Vaccine

This study uses a randomized, blinded and controlled design, with age stratification of 18-59 years and ≥60 years , including the test vaccine at different doses (30 μg and 60 μg) and an active control vaccine. A total of 980 subjects will be enrolled in this study. 490 subjects aged 18-59 years will be randomly assigned to cohort A1 (test vaccine dose 1), A2 (test vaccine dose 2) and A3 (control vaccine) for the 2-dose regimen (0,28-day) and to cohort A4 (test vaccine dose 1), A5 (test vaccine dose 2) and A6 (active control) for the 1-dose regimen in a ratio of 3:3:1:3:3:1. Another 490 subjects aged 60 years or older will be randomized to cohort B1 (test vaccine dose 1), B2 (test vaccine dose 2) and B3 (active control) for the 2-dose regimen (0,28-day), and cohort B4 (test vaccine dose 1), B5 (test vaccine dose 2) and B6 (control vaccine) for the 1-dose regimen in a ratio of 3:3:1:3:3:1.