A Study of Dengue Vaccine in Healthy Children, Teenagers and Adults in India

A Randomized, Double-Blind, Placebo-Controlled, Phase 3 Trial to Investigate the Safety and Immunogenicity of a Dengue Tetravalent Vaccine (Live, Attenuated) (TDV) Administered Subcutaneously to Healthy Subjects Aged 4 to 60 Years in India

The main aims of the study are to learn about side effects and a participant's immune response to Takeda's Dengue Vaccine when given twice within 3 months.

Participants will receive 2 doses of their randomized treatment (vaccine or placebo). Children, teenagers and adults will receive one dose of either the vaccine or placebo on Day 1 and the second dose of either the vaccine or placebo 3 months later. Up to 4 blood samples will be taken throughout the study.

During the study, participants will visit their study clinic 6 times.

The vaccine being tested in this study is called TDV (Live, Attenuated). TDV is being tested to prevent dengue. This study will assess the safety and immunogenicity of TDV in healthy participants.

The study will enroll approximately 480 patients. Participants will be randomly assigned (by chance, like flipping a coin) to receive either TDV or placebo- which will remain undisclosed to the participant, and investigator during the study:

• Cohort 1, ≥18 to ≤60 Age Group: TDV
• Cohort 1, ≥18 to ≤60 Age Group: Placebo
• Cohort 2, ≥4 to <18 Age Group: TDV
• Cohort 2, ≥4 to <18 Age Group: Placebo

This multi-center trial will be conducted in India. The overall duration of the study is approximately 9 months.

Key Inclusion Criteria:

1. Participants who can comply with trial procedures and are available for the duration of follow-up.

Key Exclusion Criteria:

At screening and at vaccination:

1. A body mass index (BMI) ≥35 kg/m^2.

2. Intent to participate in another clinical trial at any time during the conduct of this trial.

3. Plans to receive any of the following:

   1. A licensed vaccine within 14 days (for inactivated vaccines) or 28 days (for live vaccines) prior to TDV or placebo administration.
   2. A coronavirus vaccine within 14 days prior to TDV or placebo administration.
   3. A vaccine authorized for emergency use within 28 days of TDV or placebo administration.

4. Known substance or alcohol abuse within the past 2 years that may interfere with his/her ability to comply with requirements for trial participation.

5. Receipt of previous vaccination against dengue virus.

6. Previous participation in any clinical trial of a dengue candidate vaccine.

At Vaccination:

1. Participants with febrile illness or moderate or severe acute illness, or infection, at the time of random assignment.
2. Participants medicated with antipyretic and/or analgesic medication(s) within 24 hours prior to TDV or placebo administration.

NOTE: Other protocol defined Inclusion/exclusion criteria may apply.