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RecruitingNCT06665035Updated Jun 29, 2026

A Study of 2 Doses of Tetravalent Dengue Vaccine (TDV) in Infants and Toddlers

A Phase 3 interventional study of TDV and Placebo in Dengue Fever, sponsored by Takeda. Recruiting at 4 sites in 2 countries. Open to participants aged 6 Months to 20 Months, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-06-29.

Sponsored by Takeda · Phase 3, Interventional, and Prevention

From the registry’s dates

  • Started Jun 2025; still recruiting 1 year 4 months later.
Phase
Phase 3
Study type
Interventional
Enrollment
212
Allocation
Randomized
Ages
6 Months to 20 Months
Sex
All
01

Study summary

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.

02

Conditions studied

  • Dengue Fever

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Keywords

  • Drug Therapy
03

In context

Dengue

283 studies on the registry are indexed under Dengue; 44 are open to participants now.

This study's planned enrollment of 212 is above the median of 132 across 197 interventional studies indexed under Dengue.

Browse Dengue studies →

Lead sponsor

Takeda is the lead sponsor of 1,026 studies on the registry; 89 are open to participants now.

Of its 178 completed or terminated interventional studies of FDA-regulated products, 154 (87%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
6 Months to 20 Months
Sexes eligible
All
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

Participant eligibility is determined according to the following criteria:

  1. Participant is aged >=6 to \<21 months at the time of entry into the trial.
  2. Participant is male or female.
  3. 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.
  4. Participant's legally acceptable representative (LAR) has signed and dated a written 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.
  5. 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.

Exclusion criteria

Exclusion Criteria

Any participant who meets any of the following criteria will not qualify for randomization:

  1. Participant has (s), warning(s) and/or precaution(s) applicable to vaccination with TDV as specified in the investigator's brochure (IB)and/or the approved product label (as applicable) in the participating country.
  2. Participant has a known or allergy to any of the medicinal product (IMP) components (including ).
  3. Participant has behavioral or cognitive impairment or psychiatric disease that, in the opinion of the investigator, may interfere with the participant's ability to participate in the trial.
  4. Participant has a history of progressive or severe neurologic disorder, seizure disorder or neuro-inflammatory disease (example, Guillain-Barré syndrome).
  5. Participant has an illness, or history of any illness that, in the opinion of the investigator, might interfere with the results of the trial or pose additional risk to the participant due to involvement in this trial.
  6. Participant has a known or suspected impairment/alteration of immune function, including:

    1. Chronic administration of oral and/or parenteral at doses considered sufficiently (example, >=2 mg/kg [milligrams per kilograms] body weight/day prednisone [or equivalent] for 14 consecutive days, or, >=20 milligram per day [mg/day] prednisone [or equivalent] for >=14 consecutive days) within 60 days prior to Day 1 month 0 (M0) (note: use of corticosteroids by inhaled, intranasal, intraarticular, bursal, tendon injection, or topical routes is allowed).
    2. Receipt of blood, immunoglobulins, blood products, and/or plasma derivatives within the 3 months prior to Day 1 (M0).
    3. Receipt of immunostimulants within 60 days prior to Day 1 (M0).
    4. Immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy within 6 months prior to Day 1 (M0).
    5. infection or HIV-related disease.
    6. virus infection.
    7. virus infection.
    8. Genetic immunodeficiency.
  7. Participant has known or suspected abnormalities of splenic or thymic function.
  8. Participant has a known bleeding diathesis, or any condition/medication that may be associated with a prolonged bleeding time.
  9. Participant has a serious chronic or progressive disease deemed to be preclusive to trial entry, that is., not medically stable according to the judgment of the investigator.
  10. Participant has previously received a vaccination against dengue virus (investigational or licensed).
  11. Participant has a active infection (as assessed by the investigator) or body temperature greater than (>) 38.0 degrees Celsius (°C) (>100.4 degrees Fahrenheit [°F]) within 3 days of intended IMP administration on Day 1 (M0).
  12. Participant has used antipyretics and/or analgesic medications within 24 hours prior to vaccination. The reason for their use (prophylaxis vs treatment) must be documented. Trial entry must be delayed to allow for a full 24 hours to have passed since last use of antipyretics and/or analgesic medications.
  13. Participant has received any of the following:

    1. A licensed vaccine within 14 days (for inactivated vaccines) or 28 days (for ) prior to IMP administration on Day 1 (M0). This includes co-administration with routine vaccines.
    2. A coronavirus vaccine within 14 days prior to IMP administration on Day 1 (M0).
    3. A vaccine authorized for emergency use within 28 days prior to IMP administration on Day 1 (M0).
  14. Participant is scheduled to receive any other vaccine within 28 days after IMP administration on Day 1 (M0).
  15. Participant is participating in any clinical trial with another investigational product 30 days prior to Day 1 (M0) or plans to participate in another clinical trial at any time during the conduct of this trial.
  16. Participant has taken part in any clinical trial of a dengue or other flavivirus (example, West Nile virus) candidate vaccine, except if it is known that the participant received placebo in the trial(s).
  17. A first degree relative is involved in the conduct of this trial.
Terms in these criteria, in plain language(12)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Contraindication

A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.

Hypersensitivity

An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

Excipients

The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

Immunosuppression

A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.

Read whether the line is about a condition or about medicines, and which medicines and doses it means.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

Live vaccines

Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.

05

Study design

Phase
Phase 3
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Sequential assignment
Masking
Double (Participant, Investigator)
Enrollment
212 participants (estimated)

Study arms

  • Experimental
    Cohort 1: Tetravalent Dengue Vaccine (TDV) 0.5 mL (Age group: >=12 to <21 months)

    Participants with the age group \>= 12 to \< 21 months receive TDV 0.5 mL subcutaneous (SC) injection, on Day 1 and Day 90.

    Biological: TDV

  • Experimental
    Cohort 1: Placebo (Age group: >=12 to <21 months)

    Participants with the age group \>= 12 to \< 21 months receive placebo (normal saline), SC injection, on Day 1 and Day 90.

    Other: Placebo

  • Experimental
    Cohort 2: TDV 0.5 mL(Age group: >=6 to <12 months)

    Participants with the age group \>=6 to \<12 months receive TDV, 0.5 mL SC injection, on Day 1 and Day 90.

    Biological: TDV

  • Experimental
    Cohort 2: Placebo (Age group: >=6 to <12 months)

    Participants with the age group \>=6 to \<12 months receive placebo (normal saline), SC injection, on Day 1 and Day 90.

    Other: Placebo

Interventions

  • BiologicalTDV

    TDV SC injection.

    Also known as: QDENGA, TAK-003

  • OtherPlacebo

    Placebo SC injection.

06

What researchers measure

Primary outcomes

  1. Percentage of Participants with Solicited Local (Injection Site) Adverse Events (AEs) Within 7 Days Post Vaccination at Day 1 (Overall and by Severity)

    Solicited local AEs are injection site pain/tenderness, erythema, and swelling at the vaccination site. All solicited AEs at the injection site will be considered related to the study vaccine administration. The AEs of severity will be graded by investigator as Grade 1: mild, Grade 2: moderate and Grade 3: severe.

    Time frame: Within 7 Days post-vaccination at Day 1

  2. Percentage of Participants with Solicited Local (Injection Site) AEs Within 7 Days Post Vaccination at Day 90 (Overall and by Severity)

    Solicited local AEs are injection site pain/tenderness, erythema, and swelling at the vaccination site. All solicited AEs at the injection site will be considered related to the study vaccine administration. The AEs of severity will be graded by investigator as Grade 1: mild, Grade 2: moderate and Grade 3: severe.

    Time frame: Within 7 days post-vaccination at Day 90

  3. Percentage of Participants with Solicited Systemic AEs Within 14 Days Post Vaccination at Day 1 (Overall and by Severity)

    Solicited systemic AEs include fever (body temperature greater than or equal to \[\>=\] 38-degree Celsius \[C\], drowsiness, irritability/fussiness and loss of appetite. The AEs of severity will be graded by investigator as Grade 1: mild, Grade 2: moderate and Grade 3: severe.

    Time frame: Within 14 days post-vaccination at Day 1

  4. Percentage of Participants with Solicited Systemic AEs Within 14 Days Post Vaccination at Day 90 (Overall and by Severity)

    Solicited systemic AEs include fever (body temperature \>= 38 degree (C), drowsiness, irritability/fussiness and loss of appetite. The AEs of severity will be graded by investigator as Grade 1: mild, Grade 2: moderate and Grade 3: severe.

    Time frame: Within 14 days post-vaccination at Day 90

  5. Percentage of Participants with Unsolicited AEs Within 28 Days Post Vaccination at Day 1

    An unsolicited AE is any AE reported by the participant that is not specified as a solicited AE or is specified as a solicited AE but starts outside the period for reporting a solicited AE (that is, 7 days and 14 days in total including the day IMP administration).

    Time frame: Within 28 days post-vaccination at Day 1

  6. Percentage of Participants with Unsolicited AEs Within 28 Days Post Vaccination at Day 90

    An unsolicited AE is any AE reported by the participant that is not specified as a solicited AE or is specified as a solicited AE but starts outside the period for reporting a solicited AE (that is, 7 days and 14 days in total including the day of IMP administration).

    Time frame: Within 28 days post-vaccination at Day 90

  7. Percentage of Participants with Medically-attended AEs (MAAEs)

    MAAEs are defined as AEs leading to an unscheduled visit to or by a healthcare professional including visits to an emergency department (medically attended visits), but not fulfilling seriousness criteria.

    Time frame: From Day 1 through the end of trial (up to Day 1170)

  8. Percentage of Participants with Serious Adverse Events (SAEs)

    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.

    Time frame: From Day 1 through the end of trial (up to Day 1170)

  9. Geometric Mean Titers (GMTs) of Neutralizing Antibodies by Microneutralization Test (MNT) for Each of 4 Dengue Virus Serotypes at Day 120

    GMTs of neutralizing antibodies will be measured by MNT against 4 dengue virus serotypes. The 4 dengue virus serotypes are dengue virus (DENV-1, DENV-2, DENV-3 and DENV-4) will be reported.

    Time frame: Day 120

Secondary outcomes

  1. GMTs of Neutralizing Antibodies by MNT for Each of the 4 Dengue Virus Serotypes

    GMTs of neutralizing antibodies will be measured by MNT against 4 dengue virus serotypes. The 4 dengue virus serotypes are DENV-1, DENV-2, DENV-3 and DENV-4.

    Time frame: Day 1, Day 30, Day 270, Day 450, Day 810 and Day 1170

  2. Seropositivity Rates for 4 Dengue Virus Serotypes

    Seropositive rate is defined the percentage of participants with MNT titer \>=10 against each of the four dengue virus serotypes. The four dengue virus serotypes (DENV-1, DENV-2, DENV-3 and DENV-4) will be reported.

    Time frame: Day 1, Day 30, Day 120, Day 270, Day 450, Day 810 and Day 1170

  3. Seropositivity Rates For Multiple (2, 3, or 4) Dengue Virus Serotypes

    Seropositive rate is defined the percentage of participants with MNT titer \>=10 against multiple (2, 3, or 4) dengue virus serotypes. The 4 dengue virus serotypes are DENV-1, DENV-2, DENV-3 and DENV-4.

    Time frame: Day 1, Day 30, Day 120, Day 270, Day 450, Day 810 and Day 1170

07

Study locations

1 of 4 sites recruiting
08

References and documents

Individual participant data

Plan to share: Yes — Takeda provides access to the de-identified individual participant data (IPD) for eligible studies to aid qualified researchers in addressing legitimate scientific objectives (Takeda's data sharing commitment is available on https://clinicaltrials.takeda.com/takedas-commitment?commitment=5). These IPDs will be provided in a secure research environment following approval of a data sharing request, and under the terms of a data sharing agreement.

Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report

Access criteria: IPD from eligible studies will be shared with qualified researchers according to the criteria and process described on https://vivli.org/ourmember/takeda/. For approved requests, the researchers will be provided access to anonymized data (to respect patient privacy in line with applicable laws and regulations) and with information necessary to address the research objectives under the terms of a data sharing agreement.

Data sharing details ↗ · vivli.org

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jun 29, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT06665035
Lead sponsor
Takeda
Responsible party
Sponsor
First posted
Oct 30, 2024
Start date
Jun 16, 2025
Primary completion
Mar 3, 2030 (estimated)
Completion
Mar 3, 2030 (estimated)
Last update
Jun 29, 2026

Study contacts

Takeda Contact
Contact
medinfoUS@takeda.com
+1-877-825-3327
Study Director Study Director
study director · Takeda

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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