A Seamless Phase II/III, Observer-blind, to Evaluate Immunogenicity and Safety of Chikungunya Virus Vaccine in Healthy Subjects 12-65Years of Age.

Exclusion Criteria10

• \. Subject a known case of diabetes mellitus (Type 1 and 2). 3. History of degenerative neurological disease (e.g. Guillain Barre Syndrome, Multiple Sclerosis).
• \. Any clinically significant laboratory values or illness or any other current or pre-existing health condition (e.g. any major pulmonary, cardiovascular, renal, neurological, metabolic, gastro-intestinal, hepato-biliary, haematological functional abnormality, mental or physical disability, blood dyscrasia, major congenital defects, etc.) which in the opinion of the Investigator may affect the safety of the subject or the study endpoints.
• \. History of allergic/hypersensitivity reactions or anaphylaxis to any vaccine or components of study vaccine.
• \. Subject has any acute illness (moderate or severe) at the time of vaccination and/or fever (oral temperature ≥ 38°C or ≥ 100.4 °F) within 48 hours prior to vaccination.
• \. Subject has history of cancer, organ transplant, any other clinically significant immunosuppressive condition or autoimmune disease (e.g. Systemic Lupus Erythematosus, autoimmune thyroid disease). 8. Subjects who are pregnant or breastfeeding. 9. Prior major surgery or radiation therapy within 4 weeks of Visit 1. 10. Known or suspected cases of HIV and Hepatitis B surface antigen (HBsAg); or any potentially communicable infectious disease as determined by the Investigator.
• \. Current (within 14 days before Visit 1) or anticipated concomitant immune-modifying or immunosuppressive therapy (excluding inhaled, topical skin, or eye drop-containing corticosteroids, low-dose methotrexate, or corticosteroids at a dose less than 20 mg/day).
• \. Administration of blood or blood product derivatives or any immunoglobulin preparation, 90 days before Visit 1.
• \. Active addictive drug or alcohol use or dependence that, in the opinion of the Investigator, would interfere with adherence to study requirements or assessment of immunologic endpoints.
• \. Participating in a clinical trial of any vaccine, including CHIKV, within 30 days before Visit 1 or planning to participate during the study.
• \. Any other condition which in the opinion of the Investigator may affect subject's safety or participation.