Immunogenicity and Safety of ChimeriVax™ Japanese Encephalitis Vaccine in Thai Toddlers and Children
Condition: Japanese Encephalitis; Hepatitis A
MeSH terms: Hepatitis A; Encephalitis, Japanese; Hepatitis; Encephalitis
Intervention: Japanese encephalitis vaccine (Day 0) Hepatitis A vaccine (Day 28); Hepatitis A vaccine (Day 0) Japanese encephalitis vaccine (Day 28); Japanese encephalitis vaccine (Day 0) Hepatitis A vaccine (Day 28); Hepatitis A vaccine (Day 0) Japanese encephalitis vaccine (Day 28)
Intervention description: ≥4.0 Log10 Plaque forming units (PFU), Subcutaneous (SC; Day 0); 0.5 mL intramuscular (IM; Day 28); 0.5 mL IM (Day 0); ≥4.0 Log10 PFU SC (Day 28); ≥4.0 Log10 PFU SC (Day 0); 0.5 mL IM (Day 28); 0.5 mL IM (Day 0); ≥4.0 Log10 PFU SC (Day 28)
Intervention MeSH terms: Vaccines
Phase: Phase 2
Study type: Interventional
Primary purpose: Prevention
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Enrollment: 300.0
Sex: All
Minimum age: 12 Months
Maximum age: 5 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: Japanese encephalitis (JE); Hepatitis A; Inactivated Mouse-Brain

Summary:

      Safety:

      To describe the safety profiles following vaccination.

      Immunogenicity:

      To describe the immune response after a single dose of vaccine.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Provision of consent form signed by at least one parent or another legally acceptable
             representative, and by at least one independent witness.

          -  Completion of vaccinations according to the national immunization schedule

          -  Subject and parent/legally acceptable representative able to attend all scheduled
             visits and comply with all trial procedures.

          -  Previous receipt of two doses of a mouse-brain-derived JE vaccine at 12 to 15 months
             of age according to the national immunization schedule and aged 2 to 5 years on the
             day of inclusion.

          -  Aged 12 to 24 months on the day of inclusion and have not received any JE vaccine.

        Exclusion Criteria:

          -  Participation in another clinical trial investigating a vaccine, drug, medical device,
             or a medical procedure in the 4 weeks preceding the first trial vaccination.

          -  Known or suspected congenital or acquired immunodeficiency, immunosuppressive therapy
             such as anti-cancer chemotherapy or radiation therapy within the preceding 6 months,
             or long-term systemic corticosteroids therapy.

          -  Known systemic hypersensitivity to any of the vaccine components or history of a
             life-threatening reaction to the trial vaccine or to a vaccine containing any of the
             same substances.

          -  Chronic illness, at a stage that could interfere with trial conduct or completion, in
             the opinion of the Investigator.

          -  Receipt of blood or blood-derived products in the past 3 months, that might interfere
             with the assessment of the immune response.

          -  Receipt of hepatitis A vaccine.

          -  History of flavivirus infection (confirmed either clinically, serologically or
             microbiologically).

          -  Administration of any anti-viral within 2 months preceding the screening visit.

          -  History of central nervous system disorder or disease.

          -  Personal or family history of thymic pathology (thymoma), thymectomy, or myasthenia.

          -  Planned participation in another clinical trial during the present trial period.

          -  Receipt of any vaccine in the 4 weeks preceding the first trial vaccination.

          -  Planned receipt of any vaccine in the 4 weeks following any trial vaccination.

          -  Personal human immunodeficiency virus, hepatitis B or hepatitis C seropositivity in
             the blood sample taken at screening.

          -  Thrombocytopenia, bleeding disorder or anticoagulants in the 3 weeks preceding
             inclusion contraindicating IM vaccination.

          -  Previous vaccination against flavivirus disease at any time before the trial other
             than a mouse-brain-derived JE vaccine given in a two-dose regimen at 12 to 15 months
             of age in accordance with the national immunization schedule.

          -  Febrile illness or any acute illness/infection on the day of vaccination, according to
             investigator judgment

          -  History of seizures.

          -  Previous vaccination against flavivirus disease.