This is a phase Ⅱ, single-center, randomized, double-blind, placebo-controlled study, to evaluate the immunogenicity and safety of the recombinant COVID-19 vaccine (CHO cells) in the subjects from healthy adults and elderly adults aged 18 years and above (aged 18-60 and 60-85 years) . The phase Ⅱ clinical trials designed 4 research group, including an immunization procedures (0, 28, 56 days), two doses (20μg/0.5ml, 40μg/0.5ml) and two ages group (adults and elder): Each group including 120 participants. Vaccination or placebo group will be randomly assigned to receive in a 5:1 ratio, 480 in total.~Cellular immune blood samples were collected from the top 96 subjects (i.e., the top 24 in each study group, vaccine group: control group =5:1), and Elispot test and cytokine staining (ICS)/flow assay were performed.
This is a phase Ⅱ, randomized, placebo-controlled, double-blind study, to evaluate immunogenicity and safety of a recombinant COVID-19 vaccine (CHO cells) in the subjects from healthy adults and elderly adults aged 18 years and above (aged 18-60 and 60-85 years) with an immunization procedure (0, 28, 56 days).