A Study of Dengue Tetravalent Vaccine (TDV) in Healthy Participants in Japan

A Randomized, Double-Blind, Placebo-Controlled (Participants Aged 18 to 60 Years) and Open-Label (Participants Aged 4 to 17 Years), Phase 2/3 Trial to Evaluate the Immunogenicity and Safety of 2 Doses of a Dengue Tetravalent Vaccine (Live, Attenuated) (TDV) Administered Subcutaneously to Healthy Adults, Adolescents, and Children in Japan

Dengue fever is caused by an infection with the dengue virus. Vaccination with TDV can help prevent dengue fever.

The main purpose of this study is to learn about TDV's ability to create an immune response in adults, adolescents, and children administered. In this study, participants will receive 2 vaccinations with TDV (the second 3 months after the first). During the study, participants will visit their study clinic 5 times.

Participants will be in this study for approximately 270 days (9 months).

Inclusion Criteria:

1. Participant aged >=4 to less than or equal to (<=) 60 years at the time of signing the informed consent/pediatric assent form.
2. Participant is Japanese 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 clinical judgment of the investigator.
4. Participant and/or the participant's legally acceptable representative (LAR) who have signed and dated a written, informed consent/pediatric assent form, and any required privacy authorization prior to the initiation of any trial procedures, and after the nature of the trial has been explained.
5. Participant can comply with trial procedures and is available for the duration of follow-up.

Exclusion Criteria:

1. Participant has contraindication(s), warning(s), and/or precaution(s) applicable to vaccination with TDV as specified in the Investigator's Brochure.

2. Participant has a known hypersensitivity or allergy to any of the IMP components (including excipients of the IMP).

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 a clinically significant 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 (Month [M] 0).

   Note: In principle, oral temperature should be measured for body temperature. In cases where it is difficult to measure oral temperature, such as in young children, underarm (axillary) temperature may be used instead.

6. 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.

7. Participant has a known or suspected impairment/alteration of immune function, including:

   1. Chronic administration of oral and/or parenteral steroids at doses considered sufficiently immunosuppressive (example, >=2 milligram per kilogram [mg/kg] body weight prednisone [or equivalent] for >=14 consecutive days, or >=20 milligram per day [mg/day] prednisone [or equivalent] administered for >=14 consecutive days) within 60 days prior to Day 1 (M0), Note: use of corticosteroids by inhaled, intranasal, intra-articular, bursal, tendon injection, or topical routes is allowed.
   2. Receipt of blood, immunoglobulins, blood products, and/or plasma derivatives within the 90 days 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. Reported or known symptomatic HIV infection or asymptomatic HIV infection when accompanied by evidence of impaired immune function.
   6. Reported or known Hepatitis B and/or Hepatitis C virus infection.
   7. Genetic immunodeficiency.

8. Participant has known or suspected abnormalities of splenic or thymic function.

9. Participant has a known bleeding diathesis, or any condition that may be associated with a prolonged bleeding time.

10. 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.

11. Participant is participating in any clinical trial with another investigational product within 30 days prior to Day 1 (M0) or plans to participate in another clinical trial at any time during the conduct of this trial.

12. Participant has previously received a vaccination against flavivirus other than Japanese encephalitis (JE) (investigational or licensed).

13. Participant who received any other vaccines within 14 days (for inactivated vaccines) or 28 days (for live vaccines) prior to Day 1 (M0) or who are planning to receive any vaccine other than IMP within 28 days of IMP administration.

14. Participant who received a coronavirus vaccine within 14 days prior to Day 1 (M0).

15. Participant who received a vaccine authorized for emergency use within 28 days prior to Day 1 (M0).

16. Participant who received any JE vaccines within 28 days prior to Day 1 (M0) or who are planning to receive any JE vaccines during the trial period.

17. Previous participation in any clinical trial of a dengue or other flavivirus candidate vaccine, except for participants who received placebo in those trials.

18. Participant with body mass index (BMI) >=35 kilograms per square meter (kg/m^2) on Day 1 (M0).

19. Participant who intends to travel to dengue endemic areas during the trial period.

20. Participant with documented or suspected disease caused by a flavivirus and participants with a history of prolonged (>=1 year) habitation in a dengue endemic area.

21. Participant with history of substance or alcohol abuse within the past 2 years prior to Day 1 (M0).

22. Female participants who are pregnant (that is, a positive or indeterminate pregnancy test) or breastfeeding.

23. 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 (M0).

    1. "Childbearing potential" is defined as status post onset of menarche and not meeting any of the following conditions: menopausal for at least 2 years, status after bilateral tubal ligation for at least 1 year, status after bilateral oophorectomy, or status after hysterectomy.

    2. Acceptable contraceptive methods" are defined as one or more of the following:

       • Hormonal contraceptive.
       • Barrier method (condom or diaphragm) every time during intercourse.
       • Intrauterine device.
       • Monogamous relationship with a vasectomized partner. The partner must have been vasectomized for at least 6 months prior to the participant's trial enrollment.

24. Females of "childbearing potential" or non-sterilized males, who refuse to use an "acceptable contraceptive method" up to 6 weeks post second IMP administration on Day 90 (M3). In addition, they must be advised not to donate ova or sperm during this period.

25. A first degree relative is involved in the conduct of this trial.