A Randomized, Age-Descending, Double-Blind, Placebo-Controlled, Phase 3 Trial to Evaluate the Safety and Immunogenicity of 2 Doses of a Subcutaneous Dengue Tetravalent Vaccine (Live, Attenuated) (TDV) Administered Within the Routine Vaccination Schedule of Pediatric Participants ≥6 Months to <21 Months of Age
Dengue fever is caused by an infection with the dengue virus. Vaccination with Dengue Tetravalent Vaccine (TDV) can help prevent dengue fever. The purpose of this study is to collect information of vaccination with TDV when given to children younger than 2 years. The main aims of this study are to learn how safe the vaccine is and how well it works to activate a young child's immune system (this is called immunogenicity). Children between the age of 6 and 21 months will receive two vaccinations with either TDV or placebo 3 months apart. Blood samples will be taken before and after the vaccination as well as throughout the study. These are necessary to check how well the vaccine works to activate the immune system. During the study, participants will visit their study clinic 8 times for vaccinations, blood draws and health checks.
⁃ Participant eligibility is determined according to the following criteria:
• Participant is aged \>=6 to \<21 months at the time of entry into the trial.
• Participant is male or female.
• Participant is in good health at the time of entry into the trial as determined by medical history, physical examination (including vital signs), and the clinical judgment of the investigator.
• Participant's legally acceptable representative (LAR) has signed and dated a written informed consent form (ICF) and any required privacy authorization prior to the initiation of any trial procedure, and after the nature of the trial has been explained according to local regulatory requirements.
• The participant and participant's LAR can comply with trial procedures and can be available for the duration of follow-up, according to the LAR.