Subjects will receive 1 dose or 2 doses of LYB001, according to the immunization schedule of 0 day or 0, 28 days. The adverse events within 28 days after each vaccination will be observed. In addition, blood samples will be collected on day 0 before vaccination,and on day 7, 14, 28 and month 3, 6, 12 after full vaccination. Serum antibody levels, cellular immune responses will be analyzed to evaluate the immunogenicity and immune persistence of the vaccine.
This is a randomized, blinded, positive-controlled study to evaluate the immunogenicity and safety of Recombinant SARS-CoV-2 Vaccine (CHO Cell) LYB001, in population aged 18 years old and above（negative antibody against COVID-19）. 720 subjects will be recruited in this study, including 360 in 1 dose of 30 or 60 μg group and 360 in 2 doses of 30 or 60 μg group. The age group consists of 18-59 years old and 60 years old and above.