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

Inclusion Criteria: 1. Healthy male and female subjects aged between 12 to 65 years (both inclusive).

2. Subject or Subject's Parent should be willing to give voluntary written informed consent and/or assent prior to inclusion in the study.

3. Must be able to comprehend and comply with study requirements and procedures and be able and willing to complete subject diary.

4. Willing to consent to the storage and future use of biological samples for CHIKV related research.

5. Male subjects who are sexually active or married and female subjects who are sexually active or married and are of child-bearing potential should be willing to follow effective birth control* methods for at least 3 months after the last dose of vaccine.

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Exclusion Criteria: 1. History of rheumatoid arthritis and moderate or severe arthritis or arthralgia within past 90 days prior to Visit 1.

2. Subject a known case of diabetes mellitus (Type 1 and 2). 3. History of degenerative neurological disease (e.g. Guillain Barre Syndrome, Multiple Sclerosis).

4. 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.

5. History of allergic/hypersensitivity reactions or anaphylaxis to any vaccine or components of study vaccine.

6. 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.

7. 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.

11. 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).

12. Administration of blood or blood product derivatives or any immunoglobulin preparation, 90 days before Visit 1.

13. 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.

14. Participating in a clinical trial of any vaccine, including CHIKV, within 30 days before Visit 1 or planning to participate during the study.

15. Any other condition which in the opinion of the Investigator may affect subject's safety or participation.