Primary ObjectivesEfficacy:To evaluate the efficacy of the recombinant SARS-CoV-2 fusion protein vaccine V-01 for the prevention of symptomatic RT-PCR-positive COVID-19 (mild or above severity) starting from at least 14 days (=15 days) after full-course immunization (completing all vaccinations)Safety:To evaluate the incidence of adverse events (AEs) of recombinant SARS-CoV-2 fusion protein vaccine (V-01) from the first vaccination to 28 days after full-course immunization;

Primary ObjectivesEfficacy:To evaluate the efficacy of the recombinant SARS-CoV-2 fusion protein vaccine V-01 for the prevention of symptomatic RT-PCR-positive COVID-19 (mild or above severity) starting from at least 14 days (=15 days) after full-course immunization (completing all vaccinations)Safety:To evaluate the incidence of adverse events (AEs) of recombinant SARS-CoV-2 fusion protein vaccine (V-01) from the first vaccination to 28 days after full-course immunization;