Safety and Immunogenicity of Takeda's Tetravalent Dengue Vaccine (TDV) in Healthy Children

An Open Label, Phase 2 Study to Investigate Cell-mediated Immunity and Safety of a Tetravalent Dengue Vaccine Candidate (TDV) Administered Subcutaneously in Healthy Children Aged 4 to 16 Years

The purpose of this study is to assess the cellular immune responses following 2 doses given 3 months apart of tetravalent dengue vaccine candidate (TDV) in 4 to 16 years' healthy participants.

The vaccine tested in this study was TDV. This study assessed cellular immune responses and safety up to 3 years post second TDV administration to healthy children aged 4 to 16 years and in dengue endemic regions.

The study enrolled 200 participants. Participants received:

• TDV 0.5 mL subcutaneous (SC) injection into the upper arm at Day 1 (Month 0) and at Day 90 (Month 3).

This multi-center trial was conducted in Panama and Philippines. 198 participants received the 2-dose schedule of TDV, and 2 participants received only the first dose of TDV (Day 1). Participants made multiple visits to the clinic and were contacted at least every week for the entire study duration post first injection.

Main Inclusion Criteria:

1. Is aged 4 to 16 years, inclusive (Latin America) or 4 to 8 years, inclusive (Asia).
2. Are in good health at the time of entry into the study as determined by medical history, physical examination (including vital signs), and clinical judgment of the investigator.

Main Exclusion Criteria:

1. Febrile illness (body temperature ≥38°C) or moderate or severe acute illness or infection at the time of enrolment.
2. History or any illness that, in the opinion of the investigator, might interfere with the results of the study or pose an additional risk to the participant due to participation in the study.
3. Receipt of any other vaccines within 14 days (for inactivated vaccines) or 28 days (for live vaccines) prior to Day 1 (Month 0) or planning to receive any vaccines within 28 days after Day 1 (Month 0).
4. Previous participation in any clinical study of a dengue candidate vaccine, or previous receipt of any dengue vaccines (investigational or licensed).