The VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific reverse transcriptase polymerase chain reaction (RT-PCR). The primary endpoint of VE was assessed using the number of virologically-confirmed dengue fever cases that occurred during Part 1.

PPS included all participants in the FAS who had no major protocol violations. FAS included all randomized participants who received at least 1 dose of the trial vaccines. Overall number of participants analyzed is the number of participants with data available for analyses.

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of cases requiring hospitalization due to virologically-confirmed dengue fever that occurred during Part 1 and Part 2.

PPS included all participants in the FAS who had no major protocol violations. FAS included all randomized participants who received at least 1 dose of the trial vaccines. Overall number of participants analyzed is the number of participants with data available for analyses.

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of virologically-confirmed dengue fever cases that occurred during Part 1 and Part 2.

PPS included all participants in the FAS who had no major protocol violations. FAS included all randomized participants who received at least 1 dose of the trial vaccines. Overall number of participants analyzed is the number of participants with data available for analyses.

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of virologically-confirmed dengue fever cases that occurred during Part 1 and Part 2.

PPS included all participants in the FAS who had no major protocol violations. FAS included all randomized participants who received at least 1 dose of the trial vaccines. Overall number of participants analyzed is the number of participants with seronegative baseline status and with data available for analyses.

VE is defined as 1 - (λv/λC), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of virologically-confirmed dengue fever cases that occurred during Part 1 and Part 2.

PPS included all participants in the FAS who had no major protocol violations. FAS included all randomized participants who received at least 1 dose of the trial vaccines. Overall number of participants analyzed is the number of participants with seropositive baseline status and with data available for analyses.

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. Severe cases were determined by Adjudication Committee. VE was assessed using the number of severe cases due to virologically-confirmed dengue fever that occurred during Part 1 and Part 2.

PPS included all participants in the FAS who had no major protocol violations. FAS included all randomized participants who received at least 1 dose of the trial vaccines. Overall number of participants analyzed is the number of participants with data available for analyses.

Solicited local AEs at injection site are defined as pain, erythema and swelling that occurred within 7 days after each vaccination. The participant/legal guardian recorded the severity of each AE (except erythema and swelling) according to the diary card instruction as none, mild, moderate, or severe. Severity grades for erythema and swelling were derived from the recorded diameters. Percentages were rounded off to the nearest single decimal place except the data points where rounding-up may lead to data misinterpretation.

The Safety Set (SS)- Immunogenicity Subset included all randomized participants in the safety/immunogenicity subset who received at least 1 dose of the trial vaccines (TDV or placebo). Number analyzed is the number of participants with data available for analyses for the specified category.

Solicited systemic AEs in children (< 6 years) are defined as fever, irritability/fussiness, drowsiness and loss of appetite that occurred within 14 days after each vaccination. Solicited systemic AEs in children (≥ 6 years) are defined as fever, headache, asthenia, malaise and myalgia that occurred within 14 days after each vaccination. The participant/legal guardian recorded the severity of each AE (except fever) according to the diary card instruction as none, mild, moderate, or severe. Severity grades for fever were derived from the recorded body temperature measurements and presented using the proposed temperature increments published by the Brighton Collaboration. Percentages were rounded off to the nearest single decimal place except the data points where rounding-up may lead to data misinterpretation.

The SS- Immunogenicity Subset included all randomized participants in the safety/immunogenicity subset who received at least 1 dose of the trial vaccines (TDV or placebo). Number analyzed is the number of participants with data available for analysis for the specified category.

An AE is defined as any untoward medical occurrence in a clinical investigation participant administered a trial vaccine; it does not necessarily have to have a causal relationship with trial vaccine administration. Unsolicited AEs are any AEs that are not solicited local or systemic AEs, as defined by this study. Percentages were rounded off to the nearest single decimal place.

The SS-Immunogenicity Subset included all randomized participants in the safety/immunogenicity subset who received at least 1 dose of the trial vaccines (TDV or placebo). Number analyzed is the number of participants with data available for analysis for the specified category.

An AE is defined as any untoward medical occurrence in a clinical investigation participant administered a trial vaccine; it does not necessarily have to have a causal relationship with trial vaccine administration. A serious adverse event (SAE) is any untoward medical occurrence or effect that at any dose results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability / incapacity, is a congenital anomaly / birth defect or is medically important due to other reasons than the above mentioned criteria. Percentages were rounded off to the nearest single decimal place. In the category 'Part 1 and 2 combined' participants are counted only once even if they experienced events in both Part 1 and Part 2 in order to yield total of unique participants who had SAEs.

The SS included all randomized participants who received at least one dose of the investigational product (IP) (TDV or placebo). Number analyzed is the number of participants at risk at the start of the specified analysis period.

An AE is defined as any untoward medical occurrence in a clinical investigation participant administered a trial vaccine; it does not necessarily have to have a causal relationship with trial vaccine administration. A SAE is any untoward medical occurrence or effect that at any dose results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability / incapacity, is a congenital anomaly / birth defect or is medically important due to other reasons than the above mentioned criteria. Percentages were rounded off to the nearest single decimal place except the data points where rounding-up may lead to data misinterpretation.

The SS included all randomized participants who received at least one dose of the IP (TDV or placebo). Overall number of participants analyzed are the number of participants with data available for analyses. Number analyzed is the number of participants at risk at the start of the specified analysis period.

Seropositivity rate, defined as the percentage of participants seropositive, is derived from the titers of dengue-neutralizing antibodies. Seropositivity is defined as a reciprocal neutralizing titer ≥10. The four DENV serotypes are DENV-1, DENV-2, DENV-3 and DENV-4. Percentages were rounded off to the nearest single decimal place except the data points where rounding-up may lead to data misinterpretation.

Per-Protocol Set for Immunogenicity (PPSI): all participants in Full Analysis Set for Immunogenicity (FASI) who had no major protocol violations. The FASI were based on FAS & included all randomized participants in subset for whom a valid pre-dosing and at least one valid post-dosing blood sample have been received for immunogenicity. Number analyzed is the number of participants with data available for analysis at the specified time point.

Seropositivity rate for multiple Dengue serotypes, defined as the percentage of participants seropositive for any one (monovalent), two (bivalent), three (trivalent), and four (tetravalent) dengue serotypes, as well as at least bivalent (seropositive for ≥2 dengue serotypes) and at least trivalent (seropositive for ≥3 dengue serotypes), is derived from the titers of dengue-neutralizing antibodies. Seropositive response is defined as a reciprocal neutralizing titer ≥ 10. The four DENV serotypes are DENV-1, DENV-2, DENV-3 and DENV-4. Percentages were rounded off to the nearest single decimal place except the data points where rounding-up may lead to data misinterpretation.

PPSI: all participants in FASI who had no major protocol violations. The FASI were based on FAS & included all randomized participants in subset for whom a valid pre-dosing and at least one valid post-dosing blood sample have been received for immunogenicity. Number analyzed is the number of participants with data available for analysis at the specified time point.

GMTs of neutralizing antibodies were measured via microneutralization test 50% (MNT50). The four DENV serotypes are DENV-1, DENV-2, DENV-3 and DENV-4.

PPSI: all participants in FASI who had no major protocol violations. The FASI were based on FAS & included all randomized participants in subset for whom a valid pre-dosing and at least one valid post-dosing blood sample have been received for immunogenicity. Number analyzed is the number of participants with data available for analysis at the specified time point.

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of cases due to virologically-confirmed dengue fever that occurred during the first half of Part 3.

PPS included all participants in the FAS who had no major protocol violations. FAS included all randomized participants who received at least 1 dose of the trial vaccines. Overall number of participants analyzed is the number of participants with data available for analyses.

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of cases due to virologically-confirmed dengue fever that occurred during the second half of Part 3.

PPS included all participants in the FAS who had no major protocol violations. FAS included all randomized participants who received at least 1 dose of the trial vaccines. Overall number of participants analyzed is the number of participants with data available for analyses.

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of cases requiring hospitalization due to virologically-confirmed dengue fever that occurred during the first half of Part 3.

PPS included all participants in the FAS who had no major protocol violations. FAS included all randomized participants who received at least 1 dose of the trial vaccines. Overall number of participants analyzed is the number of participants with data available for analyses.

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of cases requiring hospitalization due to virologically-confirmed dengue fever that occurred during the second half of Part 3.

PPS included all participants in the FAS who had no major protocol violations. FAS included all randomized participants who received at least 1 dose of the trial vaccines. Overall number of participants analyzed is the number of participants with data available for analyses.

The VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of virologically-confirmed dengue fever cases.

The Per-Protocol Set-Booster (PPS-B) included all participants in the FAS-B who had no major protocol violations. The Full Analysis Set-Booster (FAS-B) included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo).

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of virologically-confirmed dengue fever cases.

The PPS-B included all participants in the FAS-B who had no major protocol violations. The FAS-B included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo).

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of virologically-confirmed dengue fever cases. Participants are counted only once for the "Any Dengue Serotype" category but counted separately for each dengue serotype they belong to.

The PPS-B included all participants in the FAS-B who had no major protocol violations. The FAS-B included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo). Overall number of participants analyzed is the number of participants with seronegative baseline status and with data available for analyses.

VE is defined as 1 - (λv/λC), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of virologically-confirmed dengue fever cases. Participants are counted only once for the "Any Dengue Serotype" category but counted separately for each dengue serotype they belong to.

The PPS-B included all participants in the FAS-B who had no major protocol violations. The FAS-B included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo). Overall number of participants analyzed is the number of participants with seropositive baseline status and with data available for analyses.

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of cases requiring hospitalization due to virologically-confirmed dengue fever.

The PPS-B included all participants in the FAS-B who had no major protocol violations. The FAS-B included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo).

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. Severe cases were determined by Adjudication Committee. VE was assessed using the number of severe cases due to virologically-confirmed dengue fever.

The PPS-B included all participants in the FAS-B who had no major protocol violations. The FAS-B included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo).

The VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of virologically-confirmed dengue fever cases. Participants are counted only once for the any dengue serotype.

The Per-Protocol Set-Booster (PPS-B) included all participants in the FAS-B who had no major protocol violations. The Full Analysis Set-Booster (FAS-B) included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo).

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of virologically-confirmed dengue fever cases. Participants are counted separately for each dengue serotype.

The PPS-B included all participants in the FAS-B who had no major protocol violations. The FAS-B included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo).

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of virologically-confirmed dengue fever cases. Participants are counted only once for the "Any Dengue Serotype" category but counted separately for each dengue serotype they belong to.

The PPS-B included all participants in the FAS-B who had no major protocol violations. The FAS-B included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo). Overall number of participants analyzed is the number of participants with seronegative baseline status and with data available for analyses.

VE is defined as 1 - (λv/λC), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of virologically-confirmed dengue fever cases. Participants are counted only once for the "Any Dengue Serotype" category but counted separately for each dengue serotype they belong to.

The PPS-B included all participants in the FAS-B who had no major protocol violations. The FAS-B included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo). Overall number of participants analyzed is the number of participants with seropositive baseline status and with data available for analyses.

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of cases requiring hospitalization due to virologically-confirmed dengue fever.

The PPS-B included all participants in the FAS-B who had no major protocol violations. The FAS-B included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo).

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. Severe cases were determined by Adjudication Committee. VE was assessed using the number of severe cases due to virologically-confirmed dengue fever.

The PPS-B included all participants in the FAS-B who had no major protocol violations. The FAS-B included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo).

The VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of virologically-confirmed dengue fever cases.

The PPS-B included all participants in the FAS-B who had no major protocol violations. The FAS-B included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo).

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of virologically-confirmed dengue fever cases.

The PPS-B included all participants in the FAS-B who had no major protocol violations. The FAS-B included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo).

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of virologically-confirmed dengue fever cases. Participants are counted only once for the "Any Dengue Serotype" category but counted separately for each dengue serotype they belong to.

The PPS-B included all participants in the FAS-B who had no major protocol violations. The FAS-B included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo). Overall number of participants analyzed is the number of participants with seronegative baseline status and with data available for analyses.

VE is defined as 1 - (λv/λC), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of virologically-confirmed dengue fever cases. Participants are counted only once for the "Any Dengue Serotype" category but counted separately for each dengue serotype they belong to.

The PPS-B included all participants in the FAS-B who had no major protocol violations. The FAS-B included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo). Overall number of participants analyzed is the number of participants with seropositive baseline status and with data available for analyses.

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. VE was assessed using the number of cases requiring hospitalization due to virologically-confirmed dengue fever.

The PPS-B included all participants in the FAS-B who had no major protocol violations. The FAS-B included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo).

VE is defined as 1 - (λv/λc), where λv and λc denote the hazard rates for the TDV and placebo arms, respectively. A virologically-confirmed dengue case is defined as febrile illness (defined as temperature ≥38°C on any 2 of 3 consecutive days) or illness clinically suspected to be dengue by the Investigator with a positive serotype-specific RT-PCR. Severe cases were determined by Adjudication Committee. VE was assessed using the number of severe cases due to virologically-confirmed dengue fever.

The PPS-B included all participants in the FAS-B who had no major protocol violations. The FAS-B included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo).

Solicited local AEs at injection site are defined as pain, erythema and swelling that occurred within 7 days after each vaccination. The participant/legal guardian recorded the severity of each AE (except erythema and swelling) according to the diary card instruction as none, mild, moderate, or severe. Severity grades for erythema and swelling were derived from the recorded diameters. Percentages were rounded off to the nearest single decimal place.

Safety Set-Booster-Immunogenicity Subset included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo) in the safety subset. Number analyzed is the number of participants with data available for analyses for the specified category.

Solicited systemic AEs are defined as fever, headache, asthenia, malaise and myalgia that occurred within 14 days after each vaccination. The participant/legal guardian recorded the severity of each AE (except fever) according to the diary card instruction as none, mild, moderate, or severe. Severity grades for fever were derived from the recorded body temperature measurements and presented using the proposed temperature increments published by the Brighton Collaboration. Percentages were rounded off to the nearest single decimal place except the data point where rounding-up may lead to data misinterpretation.

Safety Set-Booster-Immunogenicity Subset included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo) in the safety subset. Number analyzed is the number of participants with data available for analyses for the specified category.

An AE is defined as any untoward medical occurrence in a clinical investigation participant administered a trial vaccine; it does not necessarily have to have a causal relationship with trial vaccine administration. Unsolicited AEs are any AEs that are not solicited local or systemic AEs, as defined by this study. Percentages were rounded off to the nearest single decimal place.

Safety Set-Booster-Immunogenicity Subset included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo) in the safety subset.

An AE is defined as any untoward medical occurrence in a clinical investigation participant administered a trial vaccine; it does not necessarily have to have a causal relationship with trial vaccine administration. A serious adverse event (SAE) is any untoward medical occurrence or effect that at any dose results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability / incapacity, is a congenital anomaly / birth defect or is medically important due to other reasons than the above mentioned criteria. Percentages were rounded off to the nearest single decimal place. In the category 'Part 4 and 5 combined' participants are counted only once even if they experienced events in both Part 4 and Part 5 in order to yield total of unique participants who had SAEs.

Safety Set-Booster (SS-B) included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo). Number analyzed is the number of participants at risk at the start of the specified analysis period.

An AE is defined as any untoward medical occurrence in a clinical investigation participant administered a trial vaccine; it does not necessarily have to have a causal relationship with trial vaccine administration. A SAE is any untoward medical occurrence or effect that at any dose results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability / incapacity, is a congenital anomaly / birth defect or is medically important due to other reasons than the above mentioned criteria. Percentages were rounded off to the nearest single decimal place except the data points where rounding-up may lead to data misinterpretation. In the category 'Part 4 and 5 combined' participants are counted only once even if they experienced events in both Part 4 and Part 5 in order to yield total of unique participants who had SAEs.

SS-B included all participants 4 to 11 years of age at the time of randomization in the trial (Day 1 [Month 0]) who were included in the PPS and who received the booster dose of trial vaccine (TDV or placebo). Number analyzed is the number of participants at risk at the start of the specified analysis period.

Seropositivity rate, defined as the percentage of participants seropositive, is derived from the titers of dengue-neutralizing antibodies. Seropositivity is defined as a reciprocal neutralizing titer ≥10. The four DENV serotypes are DENV-1, DENV-2, DENV-3 and DENV-4. Percentages were rounded off to the nearest single decimal place except the data points where rounding-up may lead to data misinterpretation.

Per-Protocol Set for Immunogenicity-Booster (PPSI-B):all participants in Full Analysis Set for Immunogenicity-Booster (FASI-B) who had no major protocol violations. FASI-B: all participants from FAS-B who were included in booster immunogenicity subset & for whom there is valid pre-booster measurement & at least 1 valid post-booster measurement for immunogenicity assessments. Number analyzed: participants with data available for analyses for the specified category.

Seropositivity rate for multiple Dengue serotypes, defined as the percentage of participants seropositive for any one (monovalent), two (bivalent), three (trivalent), and four (tetravalent) dengue serotypes, as well as at least bivalent (seropositive for ≥2 dengue serotypes) and at least trivalent (seropositive for ≥3 dengue serotypes), is derived from the titers of dengue-neutralizing antibodies. Seropositive response is defined as a reciprocal neutralizing titer ≥ 10. The four DENV serotypes are DENV-1, DENV-2, DENV-3 and DENV-4. Percentages were rounded off to the nearest single decimal place except the data points where rounding-up may lead to data misinterpretation.

PPSI-B: all participants in FASI-B who had no major protocol violations. FASI-B: all participants from FAS-B who were included in booster immunogenicity subset & for whom there is valid pre-booster measurement & at least 1 valid post-booster measurement for immunogenicity assessments. Number analyzed: number of participants with data available for analyses for specified category.

GMTs of neutralizing antibodies were measured via MNT50. The four DENV serotypes are DENV-1, DENV-2, DENV-3 and DENV-4.

PPSI-B: all participants in FASI-B who had no major protocol violations. FASI-B: all participants from FAS-B who were included in booster immunogenicity subset & for whom there is valid pre-booster measurement & at least 1 valid post-booster measurement for immunogenicity assessments. Number analyzed: number of participants with data available for analyses for specified category.

The GMR is the geometric mean of the ratio of the two visits being compared.

PPSI-B: all participants in FASI-B who had no major protocol violations. FASI-B: all participants from FAS-B who were included in booster immunogenicity subset & for whom there is valid pre-booster measurement & at least 1 valid post-booster measurement for immunogenicity assessments. Overall number of participants analyzed: number of participants with data available for analyses. Number analyzed: number of participants with data available for analyses for specified category.

The GMR is the geometric mean of the ratio of the two visits being compared.

PPSI-B: all participants in FASI-B who had no major protocol violations. FASI-B: all participants from FAS-B who were included in booster immunogenicity subset & for whom there is valid pre-booster measurement & at least 1 valid post-booster measurement for immunogenicity assessments. Overall number of participants analyzed: number of participants with data available for analyses. Number analyzed: number of participants with data available for analyses for specified category.

The geometric mean ratio is the geometric mean of the ratio of the two visits being compared.

PPSI-B: all participants in FASI-B who had no major protocol violations. FASI-B: all participants from FAS-B who were included in booster immunogenicity subset & for whom there is valid pre-booster measurement & at least 1 valid post-booster measurement for immunogenicity assessments. Overall number of participants analyzed: number of participants with data available for analyses. Number analyzed: number of participants with data available for analyses for specified category.

The geometric mean ratio is the geometric mean of the ratio of the two visits being compared.

PPSI-B: all participants in FASI-B who had no major protocol violations. FASI-B: all participants from FAS-B who were included in booster immunogenicity subset & for whom there is valid pre-booster measurement & at least 1 valid post-booster measurement for immunogenicity assessments. Overall number of participants analyzed: number of participants with data available for analyses. Number analyzed: number of participants with data available for analyses for specified category.