The main purpose of this study is to evaluate the efficacy of 2 doses of Tetravalent Dengue Vaccine Candidate (TDV) in preventing symptomatic dengue fever of any severity and due to any of the four dengue virus serotypes in 4 to 16 year old participants.
Who can participate
Age range
4 Years – 16 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Is aged 4 to 16 years, inclusive, at the time of randomization.
. Is in good health at the time of entry into the trial as determined by medical history, physical examination (including vital signs) and clinical judgment of the Investigator.
. The participant and/or the participant's parent/guardian signs and dates an assent/written informed consent form where applicable, and any required privacy authorization prior to the initiation of any trial procedures, after the nature of the trial has been explained according to local regulatory requirements.
. Can comply with trial procedures and are available for the duration of follow-up.
. Is included in the per-protocol set (PPS) of the trial.
. Was aged 4 to 11 years at the time of randomization in the study (Day 1 \[Month 0\]).
Exclusion criteria
. Has febrile illness (temperature ≥38°C) or moderate or severe acute illness or infection at the time of randomization.
. Has history of or any illness that, in the opinion of the Investigator, might interfere with the results of the trial or pose an additional risk to the participant due to participation in the trial.
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Vaccine Efficacy (VE) of Two Doses of Tetravalent Dengue Vaccine Candidate (TDV) in Preventing Virologically-Confirmed Dengue Fever Induced by Any Dengue Serotype
Timeframe: 30 days post-second vaccination (Day 120 [Month 4]) until the end of Part 1 (Month 15) when at least 120 cases of dengue fever were confirmed and minimum duration of participant follow-up was 12 months post-second vaccination
. Has received any other vaccine within 14 days (for inactivated vaccines) or 28 days (for live vaccines) prior to Day 1 (Month 0) or planning to receive any vaccine within 28 days after Day 1 (Month 0).
. Has participated in any clinical trial with another investigational product 30 days prior to Day 1 (Month 0) or intent to participate in another clinical trial at any time during the conduct of this trial.
. Has previously participated in any clinical trial of a dengue candidate vaccine, or previous receipt of a dengue vaccine.
. Is first degree relative of individuals involved in trial conduct.
. Females of childbearing potential who are sexually active, and who have not used any of the acceptable contraceptive methods for at least 2 months prior to Day 1 (Month 0).
. Females of childbearing potential who are sexually active, and who refuse to use an acceptable contraceptive method up to 6 weeks post-second vaccination.