Non-inferiority of the neutralising titers in adolescents versus young adults.;Non-inferiority of the neutralizing titers after third dose compared to the neutralizing titers after second dose;Number of Participants with a First Occurrence of COVID-19 of Any Severity Starting 14 Days after Second Dose of SCB-2019;Number of Participants with Serious Adverse Events (SAEs), or Medically Attended AEs (MAAEs), or AEs Leading to Early Termination, or Adverse Events of Special Interest (AESIs);Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Number of Participants with Unsolicited AEs

Non-inferiority of the neutralising titers in adolescents versus young adults.;Non-inferiority of the neutralizing titers after third dose compared to the neutralizing titers after second dose;Number of Participants with a First Occurrence of COVID-19 of Any Severity Starting 14 Days after Second Dose of SCB-2019;Number of Participants with Serious Adverse Events (SAEs), or Medically Attended AEs (MAAEs), or AEs Leading to Early Termination, or Adverse Events of Special Interest (AESIs);Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Number of Participants with Unsolicited AEs

Non-inferiority of the neutralizing titers after third dose compared to the neutralizing titers after second dose;Number of Participants with a First Occurrence of COVID-19 of Any Severity Starting 14 Days after Second Dose of SCB-2019;Number of Participants with Serious Adverse Events (SAEs), or Medically Attended AEs (MAAEs), or AEs Leading to Early Termination, or Adverse Events of Special Interest (AESIs);Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Number of Participants with Unsolicited AEs

Non-inferiority of the neutralizing titers after third dose compared to the neutralizing titers after second dose;Number of Participants with a First Occurrence of COVID-19 of Any Severity Starting 14 Days after Second Dose of SCB-2019;Number of Participants with Serious Adverse Events (SAEs), or Medically Attended AEs (MAAEs), or AEs Leading to Early Termination, or Adverse Events of Special Interest (AESIs);Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Number of Participants with Unsolicited AEs

Number of Participants with a First Occurrence of COVID-19 of Any Severity Starting 14 Days after Second Dose of SCB-2019;Number of Participants with Serious Adverse Events (SAEs), or Medically Attended AEs (MAAEs), or AEs Leading to Early Termination, or Adverse Events of Special Interest (AESIs);Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Number of Participants with Unsolicited AEs

Number of Participants with a First Occurrence of COVID-19 of Any Severity Starting 14 Days after Second Dose of SCB-2019;Number of Participants with Serious Adverse Events (SAEs), or Medically Attended AEs (MAAEs), or AEs Leading to Early Termination, or Adverse Events of Special Interest (AESIs);Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Number of Participants with Unsolicited AEs

Number of Participants with a First Occurrence of COVID-19 of Any Severity Starting 14 Days after Second Dose of SCB-2019;Number of Participants with a First Occurrence of Moderate-to-Severe COVID-19 Starting 14 Days after Second Dose of SCB-2019;Number of Participants with Serious Adverse Events (SAEs), or Medically Attended AEs (MAAEs), or AEs Leading to Early Termination, or Adverse Events of Special Interest (AESIs);Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Number of Participants with Unsolicited AEs

Number of Participants with a First Occurrence of COVID-19 of Any Severity Starting 14 Days after Second Dose of SCB-2019;Number of Participants with a First Occurrence of Moderate-to-Severe COVID-19 Starting 14 Days after Second Dose of SCB-2019;Number of Participants with Serious Adverse Events (SAEs), or Medically Attended AEs (MAAEs), or AEs Leading to Early Termination, or Adverse Events of Special Interest (AESIs);Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs);Number of Participants with Unsolicited AEs