Study of a Tetravalent Dengue Vaccine in Healthy Adult Subjects Aged 18 to 45 Years in India

The aim of this study is to evaluate the immunogenicity and safety of the CYD dengue vaccine in India adult subjects.

Primary Objectives:

* To describe the neutralizing antibody response to each dengue virus serotype before the first vaccination and after each vaccination with CYD dengue vaccine in all subjects.
* To describe the safety of the CYD dengue vaccine after each dose in all subjects.

Secondary Objective:

* To detect symptomatic dengue cases occurring at any time in the trial.

Participants will receive 3 doses of their randomized treatment (vaccine or placebo). Flavivirus status will be determined at baseline (before the first dose) and the vaccine immunogenicity assessment will be at 28 days after each vaccination. Reactogenicity data will be collected in all subjects after each dose. Serious adverse events and adverse events of special interest will be collected throughout the study.

Eligibility Criteria:
Inclusion Criteria:

* Aged 18 to 45 years on the day of inclusion
* Informed consent form has been signed and dated by the subject (and by an independent witness, if applicable)
* Subject is able to attend all scheduled visits and to comply with all trial procedures
* Subject in good health, based on medical history and physical examination

Exclusion Criteria:

* Subject is pregnant, or lactating, or of childbearing potential (to be considered of non-childbearing potential, a female must be post-menopausal for at least 1 year, surgically sterile, or using an effective method of contraception or abstinence from at least 4 weeks prior to the first vaccination and until at least 4 weeks after the last vaccination)
* Participation in another clinical trial investigating a vaccine, drug, medical device, or medical procedure in the 4 weeks preceding the first trial vaccination
* Planned participation in another clinical trial during the present trial period
* Planned receipt of any vaccine in the 4 weeks following any trial vaccination
* Receipt of blood or blood-derived products in the past 3 months, which might interfere with assessment of the immune response
* Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy within the preceding 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months)
* Known seropositivity for human immunodeficiency virus (HIV), hepatitis B, and hepatitis C reported by the subject
* Known systemic hypersensitivity to any of the vaccine components, or history of a life-threatening reaction to the vaccine(s) used in the trial or to a vaccine containing any of the same substances
* Chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with trial conduct or completion
* Current alcohol abuse or drug addiction that might interfere with the ability to comply with trial procedures
* Deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalized involuntarily
* Identified as an Investigator or employee of the Investigator or study center, with direct involvement in the proposed study, or identified as an immediate family member (i.e., parent, spouse, natural or adopted child) of the Investigator or employee with direct involvement in the proposed study.