Immunogenicity Study of the Japanese Encephalitis Vaccine IC51

Observer Blinded, Randomized Phase 3 Study to Investigate the Non-Inferiority of IC51 vs. JE-VAX as Vaccines for Japanese Encephalitis in Healthy Subjects

The objective is to demonstrate the non-inferiority of the Japanese Encephalitis vaccine IC51 compared to JE-VAX in healthy subjects aged > or = 18 years

Inclusion Criteria:

• At least 18 years of age
• Written informed consent obtained prior to study entry

Exclusion Criteria:

• History of clinical manifestation of any flavivirus infection
• History of vaccination against Japanese encephalitis (JE), Yellow fever and Dengue fever (an anti-JEV neutralizing antibody titer >= 1:10 at baseline is acceptable for inclusion, these subjects will be part of the safety population, but will not be analyzed for immunogenicity in the per-protocol analysis)
• Use of any other investigational or non-registered drug or vaccine in addition to the study vaccine during the study period or within 30 days preceding the first dose of study vaccine
• Immunodeficiency including post-organ-transplantation or immunosuppressive therapy
• A family history of congenital or hereditary immunodeficiency
• History of autoimmune disease
• Any acute infections within 4 weeks prior to enrollment
• Infection with HIV, Hepatitis B or Hepatitis C
• Pregnancy, lactation or unreliable contraception in female subjects