Phase 2, select optimal dose level of SCB-2019 vaccine by age cohort (5-11 years, 2-4 years, and < 2 years), based on safety;Phase 2, select optimal dose level of SCB-2019 vaccine by age cohort (5-11 years, 2-4 years, and < 2 years), based on safety;Phase 2, select optimal dose level of SCB-2019 vaccine in phase 2 by age cohort (5-11 years, 2-4 years, and < 2 years), based on immunogenicity;Phase 3, non-inferiority (GMT) of SARS-CoV-2 nAb titers of SCB-2019 vaccine when given to participants 2 to < 5 years as compared to young adults (18 to < 25 years);Phase 3, non-inferiority (GMT) of SARS-CoV-2 nAb titers of SCB-2019 vaccine when given to participants 5 to < 12 years as compared to young adults (18 to < 25 years);Phase 3, non-inferiority (GMT) of SARS-CoV-2 nAb titers of SCB-2019 vaccine when given to participants birth to < 2 years as compared to young adults (18 to < 25 years)

Phase 2, select optimal dose level of SCB-2019 vaccine by age cohort (5-11 years, 2-4 years, and < 2 years), based on safety;Phase 2, select optimal dose level of SCB-2019 vaccine by age cohort (5-11 years, 2-4 years, and < 2 years), based on safety;Phase 2, select optimal dose level of SCB-2019 vaccine in phase 2 by age cohort (5-11 years, 2-4 years, and < 2 years), based on immunogenicity;Phase 3, non-inferiority (GMT) of SARS-CoV-2 nAb titers of SCB-2019 vaccine when given to participants 2 to < 5 years as compared to young adults (18 to < 25 years);Phase 3, non-inferiority (GMT) of SARS-CoV-2 nAb titers of SCB-2019 vaccine when given to participants 5 to < 12 years as compared to young adults (18 to < 25 years);Phase 3, non-inferiority (GMT) of SARS-CoV-2 nAb titers of SCB-2019 vaccine when given to participants birth to < 2 years as compared to young adults (18 to < 25 years)