Phase I Trial of a Recombinant SARS-CoV-2 Vaccine (Sf9 Cell)

This is a phase I, single-center, randomized, placebo-controlled, double-blind study, to evaluate safety, tolerability and immunogenicity of a recombinant SARS-CoV-2 vaccine (Sf9 cell) in Chinese healthy population aged 18 years and older. After randomization, the trial for each subject will last for approximately 13 months. Screening period is 1 week prior to randomization (Day -7 to Day -1), and each dose of either SARS-CoV-2 vaccine (Sf9 Cell) or placebo will be given intramuscularly (IM) on Day 0 and Day 28 for a two-dose regimen, or on Day 0, Day 14, and Day 28 for a three-dose regimen. Subjects who are ?18 years old and ? 55 years old will be enrolled in adult group, and healthy elderly population who are >55 years old will be enrolled in elderly group. After adult group completes the follow-up 7 days after first vaccination, elderly group will be recruited.