Groups 1, 2, 3, 4, 5 and 6: Number of Participants with MAAEs;Groups 1, 2, 3, 4, 5 and 6: Number of Participants with Medically-attended Adverse Events (MAAEs);Groups 1, 2, 3, 4, 5 and 6: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 1;Groups 1, 2, 3, 4, 5 and 6: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 2;Groups 1, 2, 3, 4, 5 and 6: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 1;Groups 1, 2, 3, 4, 5 and 6: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 2;Groups 1, 2, 3, 4, 5 and 6: Number of Participants with Unsolicited AEs 28 Days Post-dose 1;Groups 1, 2, 3, 4, 5 and 6: Number of Participants with Unsolicited AEs 28 Days Post-dose 2;Groups 1, 2, 3, 4, 5 and 6: Serological Response to Vaccination Measured by S-ELISA or Equivalent Assay 14 Days Post-dose 2;Groups 1, 2, 3, 4, 5 and 6: Serological Response to Vaccination Measured by Spike-enzyme-linked Immunosorbent Assay (S-ELISA) or Equivalent Assay 28 Days Post-dose 1;Groups 1, 2, 3, 4, 5 and 6: Serological Response to Vaccination Measured by Virus Neutralization Assay (VNA) Titers 28 Days Post-dose 1;Groups 1, 2, 3, 4, 5 and 6: Serological Response to Vaccination Measured by VNA Titers 14 Days Post-dose 2;Groups 1, 2 and 3: Number of Participants with Adverse Events of Special Interest (AESI) (Including Multisystem Inflammatory Syndrome in Children [MIS-C]);Groups 1, 2 and 3: Number of Participants with MAAEs Leading to Discontinuation;Groups 1, 2 and 3: Number of Participants with Serious Adverse Events (SAEs);Groups 4, 5 and 6: Number of Participants with AESI (Including MIS-C);Groups 4, 5 and 6: Number of Participants with MAAEs Leading to Discontinuation;Groups 4, 5 and 6: Number of Participants with SAEs

Groups 1, 2, 3, 4, 5 and 6: Number of Participants with MAAEs;Groups 1, 2, 3, 4, 5 and 6: Number of Participants with Medically-attended Adverse Events (MAAEs);Groups 1, 2, 3, 4, 5 and 6: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 1;Groups 1, 2, 3, 4, 5 and 6: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 2;Groups 1, 2, 3, 4, 5 and 6: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 1;Groups 1, 2, 3, 4, 5 and 6: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 2;Groups 1, 2, 3, 4, 5 and 6: Number of Participants with Unsolicited AEs 28 Days Post-dose 1;Groups 1, 2, 3, 4, 5 and 6: Number of Participants with Unsolicited AEs 28 Days Post-dose 2;Groups 1, 2, 3, 4, 5 and 6: Serological Response to Vaccination Measured by S-ELISA or Equivalent Assay 14 Days Post-dose 2;Groups 1, 2, 3, 4, 5 and 6: Serological Response to Vaccination Measured by Spike-enzyme-linked Immunosorbent Assay (S-ELISA) or Equivalent Assay 28 Days Post-dose 1;Groups 1, 2, 3, 4, 5 and 6: Serological Response to Vaccination Measured by Virus Neutralization Assay (VNA) Titers 28 Days Post-dose 1;Groups 1, 2, 3, 4, 5 and 6: Serological Response to Vaccination Measured by VNA Titers 14 Days Post-dose 2;Groups 1, 2 and 3: Number of Participants with Adverse Events of Special Interest (AESI) (Including Multisystem Inflammatory Syndrome in Children [MIS-C]);Groups 1, 2 and 3: Number of Participants with MAAEs Leading to Discontinuation;Groups 1, 2 and 3: Number of Participants with Serious Adverse Events (SAEs);Groups 4, 5 and 6: Number of Participants with AESI (Including MIS-C);Groups 4, 5 and 6: Number of Participants with MAAEs Leading to Discontinuation;Groups 4, 5 and 6: Number of Participants with SAEs

Part 1: Groups 1-3: Number of Participants with Adverse Events of Special Interest (AESI) (Including Multisystem Inflammatory Syndrome in Children [MIS-C]);Part 1: Groups 1-3: Number of Participants with MAAEs Leading to Discontinuation;Part 1: Groups 1-3: Number of Participants with Serious Adverse Events (SAEs);Part 1: Groups 4-6: Number of Participants with AESI (Including MIS-C);Part 1: Groups 4-6: Number of Participants with MAAEs Leading to Discontinuation;Part 1: Groups 4-6: Number of Participants with SAEs;Part 1: Serological Response to Vaccination Measured by Enzyme-linked Immunosorbent Assay (S-ELISA) or Equivalent Assay 28 Days Post-dose 1;Part 1: Serological Response to Vaccination Measured by S-ELISA or Equivalent Assay 14 Days Post-dose 2;Part 2: Humoral Immune Response Expressed by the Geometric Mean Titer (GMT) of VNA 28 Days Post-dose 1 in Adolescents;Part 2: Humoral Immune Response Expressed by the GMT of VNA 14 Days Post-dose 2 in Adolescents;Part 2: Humoral Immune Response Expressed by the GMT of VNA 28 Days Post-dose 1 in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 14 Days Post-dose 2 in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 28 Days after First Vaccination in Adolescents;Part 2: Number of Participants with AESI (Including MIS-C);Part 2: Number of Participants with MAAEs Leading to Discontinuation;Part 2: Number of Participants with SAEs;Part 2: Serological Response to Vaccination as Measured by the GMT of VNA 14 Days Post-dose 2 in Adolescents;Parts 1 and 2: Number of Participants with MAAEs;Parts 1 and 2: Number of Participants with Medically-attended Adverse Events (MAAEs);Parts 1 and 2: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 1;Parts 1 and 2: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 2;Parts 1 and 2: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 1;Parts 1 and 2: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 2;Parts 1 and 2: Number of Participants with Unsolicited AEs 28 Days Post-dose 1;Parts 1 and 2: Number of Participants with Unsolicited AEs 28 Days Post-dose 2;Parts 1 and 2: Serological Response to Vaccination Measured by Virus Neutralization Assay (VNA) Titers 28 Days Post-dose 1;Parts 1 and 2: Serological Response to Vaccination Measured by VNA Titers 14 Days Post-dose 2

Part 1: Groups 1-3: Number of Participants with Adverse Events of Special Interest (AESI) (Including Multisystem Inflammatory Syndrome in Children [MIS-C]);Part 1: Groups 1-3: Number of Participants with MAAEs Leading to Discontinuation;Part 1: Groups 1-3: Number of Participants with Serious Adverse Events (SAEs);Part 1: Groups 4-6: Number of Participants with AESI (Including MIS-C);Part 1: Groups 4-6: Number of Participants with MAAEs Leading to Discontinuation;Part 1: Groups 4-6: Number of Participants with SAEs;Part 1: Serological Response to Vaccination Measured by Enzyme-linked Immunosorbent Assay (S-ELISA) or Equivalent Assay 28 Days Post-dose 1;Part 1: Serological Response to Vaccination Measured by S-ELISA or Equivalent Assay 14 Days Post-dose 2;Part 2: Humoral Immune Response Expressed by the Geometric Mean Titer (GMT) of VNA 28 Days Post-dose 1 in Adolescents;Part 2: Humoral Immune Response Expressed by the GMT of VNA 14 Days Post-dose 2 in Adolescents;Part 2: Humoral Immune Response Expressed by the GMT of VNA 28 Days Post-dose 1 in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 14 Days Post-dose 2 in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 28 Days after First Vaccination in Adolescents;Part 2: Number of Participants with AESI (Including MIS-C);Part 2: Number of Participants with MAAEs Leading to Discontinuation;Part 2: Number of Participants with SAEs;Part 2: Serological Response to Vaccination as Measured by the GMT of VNA 14 Days Post-dose 2 in Adolescents;Parts 1 and 2: Number of Participants with MAAEs;Parts 1 and 2: Number of Participants with Medically-attended Adverse Events (MAAEs);Parts 1 and 2: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 1;Parts 1 and 2: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 2;Parts 1 and 2: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 1;Parts 1 and 2: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 2;Parts 1 and 2: Number of Participants with Unsolicited AEs 28 Days Post-dose 1;Parts 1 and 2: Number of Participants with Unsolicited AEs 28 Days Post-dose 2;Parts 1 and 2: Serological Response to Vaccination Measured by Virus Neutralization Assay (VNA) Titers 28 Days Post-dose 1;Parts 1 and 2: Serological Response to Vaccination Measured by VNA Titers 14 Days Post-dose 2

None

Part 1: Groups 1-3: Number of Participants with Adverse Events of Special Interest (AESI) (Including Multisystem Inflammatory Syndrome in Children [MIS-C]);Part 1: Groups 1-3: Number of Participants with MAAEs Leading to Discontinuation;Part 1: Groups 1-3: Number of Participants with Serious Adverse Events (SAEs);Part 1: Groups 4-6: Number of Participants with AESI (Including MIS-C);Part 1: Groups 4-6: Number of Participants with MAAEs Leading to Discontinuation;Part 1: Groups 4-6: Number of Participants with SAEs;Part 1: Serological Response to Vaccination Measured by Enzyme-linked Immunosorbent Assay (S-ELISA) or Equivalent Assay 28 Days Post-dose 1;Part 1: Serological Response to Vaccination Measured by S-ELISA or Equivalent Assay 14 Days Post-dose 2;Part 2: Humoral Immune Response Expressed by the Geometric Mean Titer (GMT) of VNA 28 Days Post-dose 1 in Adolescents;Part 2: Humoral Immune Response Expressed by the GMT of VNA 14 Days Post-dose 2 in Adolescents;Part 2: Humoral Immune Response Expressed by the GMT of VNA 28 Days Post-dose 1 in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 14 Days Post-dose 2 in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 28 Days after First Vaccination in Adolescents;Part 2: Number of Participants with AESI (Including MIS-C);Part 2: Number of Participants with MAAEs Leading to Discontinuation;Part 2: Number of Participants with SAEs;Part 2: Serological Response to Vaccination as Measured by the GMT of VNA 14 Days Post-dose 2 in Adolescents;Parts 1 and 2: Number of Participants with MAAEs;Parts 1 and 2: Number of Participants with Medically-attended Adverse Events (MAAEs);Parts 1 and 2: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 1;Parts 1 and 2: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 2;Parts 1 and 2: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 1;Parts 1 and 2: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 2;Parts 1 and 2: Number of Participants with Unsolicited AEs 28 Days Post-dose 1;Parts 1 and 2: Number of Participants with Unsolicited AEs 28 Days Post-dose 2;Parts 1 and 2: Serological Response to Vaccination Measured by Virus Neutralization Assay (VNA) Titers 28 Days Post-dose 1;Parts 1 and 2: Serological Response to Vaccination Measured by VNA Titers 14 Days Post-dose 2

Part 1: Groups 1-3: Number of Participants with Adverse Events of Special Interest (AESI) (Including Multisystem Inflammatory Syndrome in Children [MIS-C]);Part 1: Groups 1-3: Number of Participants with MAAEs Leading to Discontinuation;Part 1: Groups 1-3: Number of Participants with Serious Adverse Events (SAEs);Part 1: Groups 4-6: Number of Participants with AESI (Including MIS-C);Part 1: Groups 4-6: Number of Participants with MAAEs Leading to Discontinuation;Part 1: Groups 4-6: Number of Participants with SAEs;Part 1: Serological Response to Vaccination Measured by Enzyme-linked Immunosorbent Assay (S-ELISA) or Equivalent Assay 28 Days Post-dose 1;Part 1: Serological Response to Vaccination Measured by S-ELISA or Equivalent Assay 14 Days Post-dose 2;Part 2: Humoral Immune Response Expressed by the Geometric Mean Titer (GMT) of VNA 28 Days Post-dose 1 in Adolescents;Part 2: Humoral Immune Response Expressed by the GMT of VNA 14 Days Post-dose 2 in Adolescents;Part 2: Humoral Immune Response Expressed by the GMT of VNA 28 Days Post-dose 1 in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 14 Days Post-dose 2 in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 28 Days after First Vaccination in Adolescents;Part 2: Number of Participants with AESI (Including MIS-C);Part 2: Number of Participants with MAAEs Leading to Discontinuation;Part 2: Number of Participants with SAEs;Part 2: Serological Response to Vaccination as Measured by the GMT of VNA 14 Days Post-dose 2 in Adolescents;Parts 1 and 2: Number of Participants with MAAEs;Parts 1 and 2: Number of Participants with Medically-attended Adverse Events (MAAEs);Parts 1 and 2: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 1;Parts 1 and 2: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 2;Parts 1 and 2: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 1;Parts 1 and 2: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 2;Parts 1 and 2: Number of Participants with Unsolicited AEs 28 Days Post-dose 1;Parts 1 and 2: Number of Participants with Unsolicited AEs 28 Days Post-dose 2;Parts 1 and 2: Serological Response to Vaccination Measured by Virus Neutralization Assay (VNA) Titers 28 Days Post-dose 1;Parts 1 and 2: Serological Response to Vaccination Measured by VNA Titers 14 Days Post-dose 2

Part 1: Serological Response to Vaccination Measured by Enzyme-linked Immunosorbent Assay (S-ELISA) or Equivalent Assay 28 Days Post-dose 1;Part 1: Serological Response to Vaccination Measured by S-ELISA or Equivalent Assay 14 Days Post-dose 2;Part 2: Humoral Immune Response Expressed by the Geometric Mean Titer (GMT) of VNA 28 Days Post-dose 1 in Adolescents;Part 2: Humoral Immune Response Expressed by the GMT of VNA 14 Days Post-dose 2 in Adolescents;Part 2: Humoral Immune Response Expressed by the GMT of VNA 28 Days Post-dose 1 in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 14 Days Post-dose 2 in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 28 Days after First Vaccination in Adolescents;Part 2: Serological Response to Vaccination as Measured by the GMT of VNA 14 Days Post-dose 2 in Adolescents;Part 2: Seroresponse Rate of VNA to 14 Days Post-dose 2;Part 2: Seroresponse Rate of VNA to 28 Days Post-dose 1;Parts 1 and 2: Number of Participants with Adverse Events of Special Interest (AESI) (Including Multisystem Inflammatory Syndrome in Children [MIS-C]);Parts 1 and 2: Number of Participants with MAAEs;Parts 1 and 2: Number of Participants with MAAEs Leading to Discontinuation;Parts 1 and 2: Number of Participants with Medically-attended Adverse Events (MAAEs);Parts 1 and 2: Number of Participants with Serious Adverse Events (SAEs);Parts 1 and 2: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 1;Parts 1 and 2: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 2;Parts 1 and 2: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 1;Parts 1 and 2: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 2;Parts 1 and 2: Number of Participants with Unsolicited AEs 28 Days Post-dose 1;Parts 1 and 2: Number of Participants with Unsolicited AEs 28 Days Post-dose 2;Parts 1 and 2: Serological Response to Vaccination Measured by Virus Neutralization Assay (VNA) Titers 28 Days Post-dose 1;Parts 1 and 2: Serological Response to Vaccination Measured by VNA Titers 14 Days Post-dose 2

Part 1: Serological Response to Vaccination Measured by Enzyme-linked Immunosorbent Assay (S-ELISA) or Equivalent Assay 28 Days Post-dose 1;Part 1: Serological Response to Vaccination Measured by S-ELISA or Equivalent Assay 14 Days Post-dose 2;Part 2: Humoral Immune Response Expressed by the Geometric Mean Titer (GMT) of VNA 28 Days Post-dose 1 in Adolescents;Part 2: Humoral Immune Response Expressed by the GMT of VNA 14 Days Post-dose 2 in Adolescents;Part 2: Humoral Immune Response Expressed by the GMT of VNA 28 Days Post-dose 1 in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 14 Days Post-dose 2 in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 28 Days after First Vaccination in Adolescents;Part 2: Serological Response to Vaccination as Measured by the GMT of VNA 14 Days Post-dose 2 in Adolescents;Part 2: Seroresponse Rate of VNA to 14 Days Post-dose 2;Part 2: Seroresponse Rate of VNA to 28 Days Post-dose 1;Parts 1 and 2: Number of Participants with Adverse Events of Special Interest (AESI) (Including Multisystem Inflammatory Syndrome in Children [MIS-C]);Parts 1 and 2: Number of Participants with MAAEs;Parts 1 and 2: Number of Participants with MAAEs Leading to Discontinuation;Parts 1 and 2: Number of Participants with Medically-attended Adverse Events (MAAEs);Parts 1 and 2: Number of Participants with Serious Adverse Events (SAEs);Parts 1 and 2: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 1;Parts 1 and 2: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 2;Parts 1 and 2: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 1;Parts 1 and 2: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 2;Parts 1 and 2: Number of Participants with Unsolicited AEs 28 Days Post-dose 1;Parts 1 and 2: Number of Participants with Unsolicited AEs 28 Days Post-dose 2;Parts 1 and 2: Serological Response to Vaccination Measured by Virus Neutralization Assay (VNA) Titers 28 Days Post-dose 1;Parts 1 and 2: Serological Response to Vaccination Measured by VNA Titers 14 Days Post-dose 2

Part 1: Serological Response to Vaccination Measured by Enzyme-linked Immunosorbent Assay (S-ELISA) or Equivalent Assay 28 Days Post-dose 1;Part 1: Serological Response to Vaccination Measured by S-ELISA or Equivalent Assay 14 Days Post-dose 2;Part 2: Change from Baseline in Seroresponse Rate of VNA to 14 Days Post-dose 2;Part 2: Change from Baseline in Seroresponse Rate of VNA to 28 Days Post-dose 1;Part 2: Humoral Immune Response Expressed by the Geometric Mean Titer (GMT) of VNA 28 Days Post-dose 1 in Adolescents and Young Adults;Part 2: Humoral Immune Response Expressed by the GMT of VNA 14 Days Post-dose 2 in Adolescents and Young Adults;Part 2: Humoral Immune Response Expressed by the GMT of VNA 14 Days Post-dose 2 in Young Adults;Part 2: Humoral Immune Response Expressed by the GMT of VNA 28 Days Post-dose 1 in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 14 Days Post-dose 2 in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 14 Days Post-dose 2 in Adolescents and Young Adults;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 14 Days Post-dose 2 in Young Adults;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 28 Days after First Vaccination in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 28 Days after First Vaccination in Adolescents and Young adults;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 28 Days Post-dose 1 in Young Adults;Part 2: Serological Response to Vaccination as Measured by the GMT of VNA 14 Days Post-dose 2 in Adolescents;Part 2: Serological Response to Vaccination as Measured by the GMT of VNA 28 Days Post-dose 1 in Young Adults;Parts 1 and 2: Number of Participants with Adverse Events of Special Interest (AESI) (Including Multisystem Inflammatory Syndrome in Children [MIS-C]);Parts 1 and 2: Number of Participants with MAAEs;Parts 1 and 2: Number of Participants with MAAEs Leading to Discontinuation;Parts 1 and 2: Number of Participants with Medically-attended Adverse Events (MAAEs);Parts 1 and 2: Number of Participants with Serious Adverse Events (SAEs);Parts 1 and 2: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 1;Parts 1 and 2: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 2;Parts 1 and 2: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 1;Parts 1 and 2: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 2;Parts 1 and 2: Number of Participants with Unsolicited AEs 28 Days Post-dose 1;Parts 1 and 2: Number of Participants with Unsolicited AEs 28 Days Post-dose 2;Parts 1 and 2: Serological Response to Vaccination Measured by Virus Neutralization Assay (VNA) Titers 28 Days Post-dose 1;Parts 1 and 2: Serological Response to Vaccination Measured by VNA Titers 14 Days Post-dose 2

Part 1: Serological Response to Vaccination Measured by Enzyme-linked Immunosorbent Assay (S-ELISA) or Equivalent Assay 28 Days Post-dose 1;Part 1: Serological Response to Vaccination Measured by S-ELISA or Equivalent Assay 14 Days Post-dose 2;Part 2: Change from Baseline in Seroresponse Rate of VNA to 14 Days Post-dose 2;Part 2: Change from Baseline in Seroresponse Rate of VNA to 28 Days Post-dose 1;Part 2: Humoral Immune Response Expressed by the Geometric Mean Titer (GMT) of VNA 28 Days Post-dose 1 in Adolescents and Young Adults;Part 2: Humoral Immune Response Expressed by the GMT of VNA 14 Days Post-dose 2 in Adolescents and Young Adults;Part 2: Humoral Immune Response Expressed by the GMT of VNA 14 Days Post-dose 2 in Young Adults;Part 2: Humoral Immune Response Expressed by the GMT of VNA 28 Days Post-dose 1 in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 14 Days Post-dose 2 in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 14 Days Post-dose 2 in Adolescents and Young Adults;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 14 Days Post-dose 2 in Young Adults;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 28 Days after First Vaccination in Adolescents;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 28 Days after First Vaccination in Adolescents and Young adults;Part 2: Humoral Immune Response Expressed by the Seroresponse Rate of the VNA 28 Days Post-dose 1 in Young Adults;Part 2: Serological Response to Vaccination as Measured by the GMT of VNA 14 Days Post-dose 2 in Adolescents;Part 2: Serological Response to Vaccination as Measured by the GMT of VNA 28 Days Post-dose 1 in Young Adults;Parts 1 and 2: Number of Participants with Adverse Events of Special Interest (AESI) (Including Multisystem Inflammatory Syndrome in Children [MIS-C]);Parts 1 and 2: Number of Participants with MAAEs;Parts 1 and 2: Number of Participants with MAAEs Leading to Discontinuation;Parts 1 and 2: Number of Participants with Medically-attended Adverse Events (MAAEs);Parts 1 and 2: Number of Participants with Serious Adverse Events (SAEs);Parts 1 and 2: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 1;Parts 1 and 2: Number of Participants with Solicited Local Adverse Events (AEs) 7 Days Post-dose 2;Parts 1 and 2: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 1;Parts 1 and 2: Number of Participants with Solicited Systemic AEs 7 Days Post-dose 2;Parts 1 and 2: Number of Participants with Unsolicited AEs 28 Days Post-dose 1;Parts 1 and 2: Number of Participants with Unsolicited AEs 28 Days Post-dose 2;Parts 1 and 2: Serological Response to Vaccination Measured by Virus Neutralization Assay (VNA) Titers 28 Days Post-dose 1;Parts 1 and 2: Serological Response to Vaccination Measured by VNA Titers 14 Days Post-dose 2