This is a phase Ⅱb, single-center, randomized, double-blind, placebo-controlled study, to evaluate the immunogenicity and safety of the recombinant COVID-19 vaccine (Sf9 cells) in the subjects from healthy adults and elderly adults aged 18 years and above (aged 18-59 and 60-85 years) . The phase Ⅱb clinical trials designed two research group, including adults group (aged 18-59 years) and elderly adults group (aged 60-85 years). Each group including 2000 participants. Vaccination or placebo group will be randomly assigned to receive in a 3:1 ratio, 4000 in total.
This is a phase Ⅱb, single-center, randomized, double-blind, placebo-controlled study, to evaluate the immunogenicity and safety of the recombinant COVID-19 vaccine (Sf9 cells) in the subjects from healthy adults and elderly adults aged 18 years and above (aged 18-59 and 60-85 years) with immunization procedures 0, 21, 42 days and doses 40μg.