The purpose of this study is to assess whether ChimeriVax™ JE vaccine (a new vaccine to be used for vaccination against Japanese encephalitis) is safe and well tolerated when compared to placebo (dummy) vaccination.

Inclusion Criteria:

• Informed consent obtained from the subject.
• Aged 18 years or above at screening.
• In good general health
• Subject available for the study duration
• For female subjects (of child bearing potential) a negative pregnancy tests at Screening and Day 0.

Exclusion Criteria:

• A history of vaccination against or infection with JE.
• Known or suspected immunodeficiency, use of immunosuppressive or antineoplastic drugs.
• History of thymoma, thymic surgery (removal) or myasthenia gravis.
• Clinically significant abnormalities on laboratory assessment
• Anaphylaxis or other serious adverse reactions characterised by urticaria or angioedema to foods, Hymenoptera (bee family) stings, or drugs including vaccines).
• Transfusion of blood or treatment with any blood product, including intramuscular or intravenous serum globulin within six months of the Screening Visit or up to Day 30.
• Administration of another vaccine or antiviral within 30 days preceding the Screening visit or up to Day 30.
• Physical examination indicating any clinically significant medical condition.
• Oral temperature >38°C (100.4°F) or acute illness within 3 days prior to inoculation.
• Intention to travel out of the area for an extended period that may affect the subjects ability to attend clinic visits prior to the study visit up to Day 30.
• Seropositive to hepatitis C virus (HCV) or HIV or positive for Hepatitis B Surface Antigen.
• Lactation or intended pregnancy in female subjects.
• Excessive alcohol consumption, drug abuse, significant psychiatric illness.
• A known or suspected physiological or structural condition that compromises the integrity of the blood-brain barrier (e.g. cerebrovascular disease, multiple sclerosis, trauma, infection, inflammation of the brain or meninges).
• Participation in another clinical study within 30 days of the screening visit for this study.
• Employee of the study site, Sponsor or Clinical Research Organization (CRO) involved with the management of the study.
• Any other reasons, which in the investigator's opinion, makes the subject unsuitable to participate in the study.