A Prospective, Open Label Study of Human T Cell Responses to Live Attenuated Japanese Encephalitis Vaccine SA14-14-2
Condition: Japanese Encephalitis; Japanese Encephalitis Vaccine
MeSH terms: Encephalitis, Japanese; Encephalitis
Intervention: Live attenuated Japanese encephalitis vaccine SA14-14-2
Intervention description: Live attenuated Japanese encephalitis vaccine SA14-14-2
Phase: Phase 4
Study type: Interventional
Primary purpose: Basic Science
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 17.0
Sex: All
Minimum age: 18 Years
Maximum age: 50 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: Japanese encephalitis; Japanese encephalitis vaccine; T lymphocyte; Immune response

Summary:

      Japanese encephalitis (JE) live attenuated vaccine SA14-14-2 has been in use for more more
      than 20 years in Asia. JE vaccine SA14-14-2 is licensed in India and has been widely used
      since 2006. JE vaccines give protection by generating a neutralizing antibody response, but
      both naturally exposed persons and patients with JE also have T cell responses. Whether JE
      vaccine SA14-14-2 elicits T cell responses is unknown. This study tests the hypothesis that T
      cell responses are generated in response to JE SA14-14-2 vaccination. The aim of this study
      is to characterize T cell responses to JE vaccine SA14-14-2 in healthy people, and to
      investigate differences in T cell responses between natural exposure, vaccination and
      disease.
    

Eligibility criteria:

        Inclusion criteria:

          -  A male or female adult between 18 and 50 years of age.

          -  Written informed consent.

          -  Free of obvious health problems as established by medical history and history-
             directed physical examination before entering the study.

          -  Expected continuous residence in India during study period, without travel outside
             India

          -  An efficacious method of contraception must be used during the study for women of
             childbearing potential.

        Exclusion Criteria:

          -  Use of any investigational or non-registered drug or vaccine other than the study
             vaccine within 30 days preceding administration of SA14-14-2 vaccine, or planned use
             during the study period.

          -  Chronic administration of immunosuppressants or other immune-modifying drugs within a
             period of six months before vaccination or at any time during the study period.

          -  Any confirmed or suspected immunosuppressive or immunodeficient condition.

          -  A family history of congenital or hereditary immunodeficiency.

          -  Any antiviral drug therapy within a period of six months before vaccination or at any
             time during the study period.

          -  History of significant allergic disease or reactions likely to be exacerbated by any
             component of the study vaccine, especially allergic disease or reactions to any
             previous dose of any vaccine.

          -  History of having received JE vaccine, yellow fever vaccine, tick-borne encephalitis
             vaccine or experimental flavivirus vaccine.

          -  History of documented JE infection.

          -  Detectable anti JE or West Nile neutralizing antibodies in screening tests.

          -  Acute disease at the time of enrollment. Entry into the study may be deferred until
             the illness is resolved.

          -  Acute or chronic, clinically significant, pulmonary, cardiovascular, hepatic,
             neurological or renal functional abnormality, as determined by history and physical or
             laboratory examination that is not controlled by drugs.

          -  Administration of immunoglobulins and/or any blood products within the three months
             preceding administration of vaccine, or planned administration during the study
             period.

          -  Seropositive for HIV, HCV or HbsAg.

          -  Lactation, pregnancy or intention to get pregnant.

          -  History of excessive alcohol consumption, drug abuse or significant psychiatric
             illness.

          -  Any other condition that in the opinion of the investigator would pose a health risk
             to the participant or interfere with the evaluation of the vaccine.