To evaluate effect of previous flavivirus exposure on the safety and immunogenicity of the ChimeriVax™ dengue tetravalent vaccine

Primary Objectives:

• To describe the safety of one injection of ChimeriVax™ dengue tetravalent vaccine.
• To describe the immune response against dengue before and after one injection of ChimeriVax™ dengue tetravalent vaccine

This study will evaluate a dengue tetravalent vaccine formulation in subjects aged 18 to 40 years and previously immunised with a dengue or YF vaccine.

Inclusion Criteria :

• Aged 18 to 40 years on the day of inclusion.
• Informed consent form signed.
• For a woman, inability to bear a child or negative serum pregnancy test.
• Completed the one-year follow-up of Study DIV12.
• Able to attend all scheduled visits and to comply with all trial procedures.
• For a woman of child-bearing potential: use of an effective method of contraception or abstinence for at least four weeks prior to vaccination and at least four weeks after vaccination.

Exclusion Criteria :

• History of thymic pathology (thymoma), thymectomy, or myasthenia gravis.
• Breast-feeding.
• Systemic hypersensitivity to any of the vaccine components or history of a life-threatening reaction to the trial vaccine or a vaccine containing the same substances.
• Previous flavivirus vaccination, e.g. Japanese encephalitis or yellow fever.
• Current abuse of alcohol or drug addiction that may interfere with the subject's ability to comply with trial procedures.
• Planned participation in another clinical trial during the present trial period.
• History of flavivirus infection (confirmed either clinically, serologically or microbiologically).
• Congenital or acquired immunodeficiency, immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy within the preceding six months, or long-term systemic corticosteroids therapy.
• Chronic illness at a stage that could interfere with trial conduct or completion.
• Blood or blood-derived products received in the past three months.
• Vaccination planned in the four weeks following the trial vaccination.
• Flavivirus vaccination planned during the present trial period.
• Planned travel during the present trial period to areas with high dengue endemicity.
• Subject deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalised without his/her consent.
• Participation in another clinical trial in the four weeks preceding the trial vaccination.
• Any vaccination in the four weeks preceding the trial vaccination.
• Human Immunodeficiency Virus (HIV), Hepatitis B (Ag HBs) or Hepatitis C (HC) seropositivity in blood sample taken at screening.
• Laboratory abnormalities considered clinically significant upon the Investigator's judgement in blood sample taken at screening.
• Positive flavivirus serological test in blood sample taken at screening (for Controls only).