Safety and Immunogenicity Study of COVID-19 Protein Subunit Recombinant Vaccine Adjuvanted With Alum+CpG 1018

This trial is observer blinded, comparative, randomized, phase I study. Approximately 175 subjects will be recruited (18 years and above). The investigational product is 0.5 ml in two dose-regimen (for all subjects) with 28 days apart between doses, compare to an active control (inactivated SARS-CoV-2 vaccine). There will be 4 formula of investigational product used with different concentration of Receptor Binding Domain (RBD) antigen and adjuvant CpG 1018.