Phase I Trial of a Recombinant COVID-19 Vaccine (CHO Cell)

This is a phase I, randomized, placebo-controlled, double-blind study, to evaluate safety and immunogenicity of a recombinant SARS-CoV-2 vaccine (CHO cell) in Chinese healthy population aged 18 years and older. Healthy adults who are ≥18 years old and ≤59 years old will be enrolled in the adult group and healthy elderly population who are \>59 years old will be enrolled in the elderly group. To ensure the enrollment of healthy subjects, screening tests (hematology, biochemistry, and urinalysis) will be performed prior to the vaccination. In the adults group, there are four regimen cohort: middle-dose at 0, 14 schedule, high-dose at 0, 14 schedule, middle-dose at 0,14, 28 schedule and high-dose at 0,14,28 schedule. In the elderly group, there are two regimen cohort: middle-dose at 0,14, 28 schedule and high-dose at 0,14,28 schedule. The subjects in regimen cohort will be randomized to receive vaccines or placebos at a ratio of 2:1. The study will set up an Independent Data Monitoring Committee (IDMC) to conduct overall supervision. The IDMC is required to review the unblinded data when a significant event or risk occurs in the study that might cause the study to be suspended.