Inclusion:

• Healthy male or female adult 18-45 years at the time of vaccination
• Free of obvious health problems as established by medical history and physical examination before entering into the study
• Written informed consent obtained from the subject
• Able to read the Subject Information Sheet and Consent Form
• Subjects who the investigator believes can and will comply with the requirements of the protocol
• Females must be of non-childbearing potential, or, if of childbearing potential, she must be abstinent or have used adequate contraceptive precautions as defined in the protocol for 30 days prior to vaccination, have a negative pregnancy test within 48 hours prior to vaccination and must agree to continue such precautions for 60 days after completion of the vaccination series

Exclusion:

History of:

• recurrent migraine headache
• any neurological or behavioral disorder or seizures
• drug abuse or alcohol consumption (more than 2 drinks per day)
• allergic disease/reaction likely to be exacerbated by vaccine
• urticaria related to mosquito bites requiring medical attention
• Acute or chronic, clinically significant pulmonary, cardiovascular, hepatic, renal, hematologic or endocrine functional defect
• Any confirmed or suspected immunosuppressive or immunodeficient condition;
• Seropositive for HBsAg, anti-HCV or anti-HIV
• Acute disease at the time of enrollment
• Chronic hepatomegaly or splenomegaly
• Use of any investigational or non-registered drug or vaccine within 30 days preceding study or planned use
• Planned administration of a vaccine not foreseen by the study protocol 30 days ±each vaccine dose
• Planned move during study
• Chronic administration (defined as more than 14 days) of immunosuppressants or other immune-modifying drugs or administration of immunoglobulins and/or blood products, within 90 days preceding the first dose or planned administration during the study period
• Any chronic systemic drug therapy to be continued during the study period