Study of CYD Dengue Vaccine in Healthy Children and Adolescents in South America

Immunogenicity and Safety of CYD Dengue Vaccine in Healthy Children and Adolescents Aged 9 to 16 Years in South America

The purpose of this study is to generate immunogenicity and safety data in preparation for efficacy studies in Latin America.

Primary Objectives:

• To describe the immune response to dengue viruses before and after each vaccination with CYD dengue vaccine.
• To evaluate the safety of each vaccination with CYD dengue vaccine.

Participants in the Dengue Vaccine Group will receive 3 vaccinations with CYD Dengue vaccine. Participants in the Control Group will receive placebo vaccinations for the first 2 vaccinations, followed by tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine adsorbed (ADACEL®) (in Venezuela) or Meningococcal A+C vaccine (in Brazil) as a way of providing therapeutic benefit to the participants in the control group.

Inclusion Criteria :

• Aged 9 to 16 years on the day of inclusion
• Participant in good health, based on medical history and physical examination
• Provision of assent form/informed consent form signed by the participant and by the parent(s) or another legally acceptable representative
• Participant and parent(s)/legally acceptable representative(s) able to attend all scheduled visits and to comply with all trial procedures
• For a female participant of child-bearing potential, avoid becoming pregnant (use of an effective method of contraception or abstinence) for at least 4 weeks prior to first vaccination until at least 4 weeks after the last vaccination

Exclusion Criteria :

• Personal or family history of thymic pathology (thymoma), thymectomy, or myasthenia
• For a female participant of child-bearing potential, known pregnancy or positive urine pregnancy test at Visit 1
• Participation in another clinical trial investigating a vaccine, drug, medical device, or a medical procedure in the 4 weeks preceding the first trial vaccination
• Breast-feeding woman
• Planned participation in another clinical trial during the present trial period
• Known or suspected congenital or acquired immunodeficiency, immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy within the preceding 6 months, or long-term systemic corticosteroids therapy
• Known systemic hypersensitivity to any of the components of any of the trial vaccines or history of a life-threatening reaction to any of the trial vaccines or to a vaccine containing any of the same substances
• Chronic illness at a stage that could interfere with trial conduct or completion, in the opinion of the Investigator
• Current alcohol abuse or drug addiction that may interfere with the participant's ability to comply with trial procedures
• Receipt of blood or blood-derived products in the preceding 3 months that might interfere with the assessment of immune response
• Receipt of any vaccine in the 4 weeks preceding the first trial vaccination
• Planned receipt of any vaccine in the 4 weeks following the first trial vaccination
• Participant deprived of freedom by administrative or court order, or in an emergency setting, or hospitalized without his/her consent
• Febrile illness (temperature ≥ 38.0 ºC) or moderate or severe acute illness/infection on the day of vaccination, according to Investigator judgment
• Thrombocytopenia, bleeding disorder or anticoagulants in the 3 weeks preceding inclusion contraindicating intramuscular vaccination
• Severe diseases with or without fever, convulsions or neurological abnormalities without treatment or in progression.