This Phase III study is a global multicenter, randomized, double-blind, placebo-controlled clinical trial to evaluate the efficacy, safety, and immunogenicity of the recombinant COVID-19 vaccine (Sf9 cells) in 40,000 participants aged 18 years and older who do not have a known history of SARS-CoV-2 infection but whose locations or circumstances put them at appreciable risk of acquiring COVID-19 or SARS-CoV-2 infection. All participants will receive three doses of either study vaccine or placebo on Day 0, Day 21, Day 42 in a ratio of 1:1.There will be two cohorts in the study: the efficacy-safety cohort and the efficacy-extended safety-immunogenicity cohort. The efficacy will be evaluated in all vaccinated participants,including population in the efficacy-safety cohort, the efficacy-extended safety immunogenicity cohort. All vaccinated participants will also be followed up to monitor incidence of SAEs, MAAEs and AESIs. The reactogenicity of the vaccine will be evaluated in the efficacy-extended safety-immunogenicity cohort. Approximately 3000 participants will be enrolled into the efficacy-extended safety-immunogenicity cohort. This cohort will undergo additional visits to collect immunogenicity data associated with receiving the recombinant COVID-19 vaccine (Sf9 cells) and to analyze the infection status.
This Phase III study is a global multicenter, randomized, double-blind,placebo controlled clinical trial to evaluate the efficacy, safety, and immunogenicity of therecombinant COVID-19 vaccine (Sf9 cells) in 40,000 participants aged 18 years and older who do not have a known history of SARS-CoV-2 infection but whose locations or circumstances put them at appreciable risk of acquiring COVID-19 or SARS-CoV-2 infection.