Ixiaro as Booster After Mouse-brain Derived Vaccines for Japanese Encephalitis

Study Overview
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Brief Summary
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The old mouse brain derived Japanese encephalitis vaccines (MBJEV) have been reported to cause serious adverse effects and are therefore replaced with the novel Ixiaro vaccine. The present study investigates whether vaccinees primed with MBJEV can be boosted with Ixiaro. Travellers receiving Japanese encephalitis vaccines are enrolled for a follow-up of immune responses in four groups: A) primary immunization with BMJEV, B) primary and secondary immunizations with MBJEV, C) primary immunizations with Ixiaro and S) Primary immunization with MBJEV and secondary immunization with Ixiaro. Immune responses are followed with help of serum samples collected before and after vaccination.

Official Title
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Ability of the New Vero-cell-derived Inactivated Japanese Encephalitis Vaccine (IXIARO) to Elicit a Booster Response in Travellers Previously Vaccinated With Traditional Mouse-brain Derived Vaccine (JE-MB)

Conditions
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Japanese Encephalitis

Intervention / Treatment
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* Biological: Mouse brain derived japanese encephalitis vaccine (MB-JEV)
* Biological: Primary and booster immunizations with MB-JEV
* Biological: C) primary immunizations with Ixiaro
* Biological: S) Ixiaro booster to MBJEV primed


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male and female travellers ≥ 18 years of age. General good health. Written informed consent. Ability to attend all visits scheduled in this study. Travellers who have previously got a primary vaccination series of 2 or 3 doses of JE-MB and now receive a booster vaccination , either MB-JEV or IXIARO, at the travel clinic for their journey to Asia, OR Travellers with no previous vaccination against JE who are given the primary vaccination series with IXIARO at a travel clinic prior to their journey to Asia. Exclusion Criteria: - < 18 years of age. Acute disease at the time of enrollment. Pregnancy or lactation. Known immunodeficiency or immune suppressive treatment. Any chronic illness that might interfere with the immune response; history of JE. Alcohol or drug abuse. Any clinically significant history of known or suspected anaphylaxis or hypersensitivity (based on the investigator's judgement).

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: A) primary immunization with MB-JEV<br>Volunteers immunized with MB-JEV | Biological: Mouse brain derived japanese encephalitis vaccine (MB-JEV)<br>* a) 2-3 doses of MB-JEV vaccine 0.5ml given on day 0, 7, 30 immunization and one booster dose of Ixiaro 0.5 ml > 2 years later<br>* Other names: Korean Green Cross;|
| Active Comparator: Primary and booster MBJEV vaccinations<br>Booster immunization with MB-JEV of vaccinees primed with MB-JEV | Biological: Primary and booster immunizations with MB-JEV<br>* 2-3 doses of MB-JEV vaccine 0.5ml given on day 0, 7, 30 as primary immunization and one booster dose of 0.5 ml > 2 years later<br>* Other names: Korean Green Cross;|
| Active Comparator: C) primary immunizations with Ixiaro<br>Primary immunization with Ixiaro 2 dose | Biological: C) primary immunizations with Ixiaro<br>* 2 0.5 ml doses of Ixiaro 28 days apart<br>* Other names: Ixiaro;|
| Active Comparator: S) Ixiaro booster to MBJEV primed<br>Actual study group:Booster immunization with Ixiaro to those primed previously with MB-JEV | Biological: S) Ixiaro booster to MBJEV primed<br>* 0.5ml Ixiaro to volunteers previously primed with 2-3 doses of MB-JEV<br>* Other names: Ixiaro;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Antibody titers 1 month after last vaccine dose | Determination of antibody titers 1 month after last vaccine dose | 1 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Antibody titers two years after vaccination | Measurement of antibody titers two years after vaccination | 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Ixiaro, japanese encephalitis vaccine, booster