Boosterability of Live Attenuated Japanese Encephalitis (JE) Vaccine in Children Who Have Previously Received Inactivated JE Vaccine
Condition: Japanese Encephalitis
MeSH terms: Encephalitis, Japanese; Encephalitis
Intervention: Live, Attenuated Japanese Encephalitis SA 14-14-2 Vaccine (LJEV)
Intervention description: Manufactured by Chengdu Institute of Biological Products (CDIBP), Chengdu, China; batch 200611A078-1. Administered subcutaneously in the right upper arm using 23 gauge needles.
Phase: Phase 4
Study type: Interventional
Primary purpose: Prevention
Allocation: Non-Randomized
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 305.0
Sex: All
Minimum age: 2 Years
Maximum age: 5 Years
Healthy volunteers: Accepts Healthy Volunteers

Summary:

      To facilitate introduction of live attenuated SA 14-14-2 Japanese encephalitis vaccine (LJEV)
      into the National Immunization Programme of Sri Lanka, we evaluated the safety and
      immunogenicity of co-administration of LJEV and measles vaccine in children at 2 and 5 years
      of age. The primary hypothesis was that the seropositivity rate at 28 days post vaccination
      of SA 14-14-2 in subjects 2 and 5 years of age who have already received at least two doses
      of mouse brain-derived inactivated JE vaccine is greater than 80%.

      Japanese encephalitis virus is the leading cause of viral neurological disease and disability
      in Asia. The severity of sequelae, together with the volume of cases, make JE the most
      important cause of viral encephalitis in the world. Approximately 3 billion people-including
      700 million children-live in areas at risk in Asia for JE. JE most commonly infects children
      between the ages of 1 and 15 years, and can also infect adults in areas where the virus is
      newly introduced. More than 50,000 cases are reported annually and cause an estimated 10,000
      to 15,000 deaths. This figure is believed to represent only a small proportion of the disease
      burden that actually exists.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Healthy child 2 years (±3 months) or 5 years (±3 months) of age at the enrollment
             visit.

          -  Subject was a full-term infant.

          -  Subject's parent or legal guardian is literate and willing to provide written informed
             consent.

          -  Subject is up-to-date for all vaccinations recommended in the Sri Lankan childhood
             immunization schedule.

        Exclusion Criteria:

          -  Enrolled in another clinical trial involving any therapy.

          -  Subject and/or parent(s) or guardian(s) are unable to attend the scheduled visits or
             comply with the study procedures.

          -  Received any non-study vaccine within 2 weeks prior to enrolment or refusal to
             postpone receipt of such vaccines until 28 days after study entry.

          -  Prior or anticipated receipt of immune globulin or other blood products, or injected
             or oral corticosteroids or other immune modulator therapy except routine vaccines
             within 6 weeks of administration of study vaccine. Individuals on a tapering dose
             schedule of oral steroids lasting <7 days may be included in the trial as long as they
             have not received more than one course within the last 2 weeks prior to enrolment.

          -  History of documented or suspected encephalitis, encephalopathy, or meningitis.

          -  History of measles.

          -  History of Japanese encephalitis.

          -  Serious adverse event related (i.e., possible, probably, definite) to previous receipt
             of any JE vaccine, if applicable.

          -  Persistent inconsolable crying (>3 hours) observed after previous receipt of any JE
             vaccine, if applicable.

          -  Hypotonic - hyporesponsiveness after past receipt of any JE vaccine, if applicable.

          -  Suspected or known hypersensitivity to any of the investigational or marketed vaccine
             components.

          -  History of serious chronic disease (cardiac, renal, neurologic, metabolic, or
             rheumatologic).

          -  Underlying medical condition such as inborn errors of metabolism, failure to thrive,
             bronchopulmonary dysplasia, or any major congenital abnormalities requiring surgery or
             chronic treatment.

          -  History of thrombocytopenic purpura.

          -  History of seizures, including history of febrile seizures, or any other neurologic
             disorder.

          -  Known or suspected immunologic function impairment of any kind and/or known HIV
             infection.

          -  Parent with known or suspected immunologic function impairment of any kind and/or
             known HIV infection.

          -  Any condition that, in the opinion of the investigator, would pose a health risk to
             the participant or interfere with the evaluation of the study objectives.