Evaluation of Immunogenicity of Different Tick Borne Encephalitis (TBE) Fast Protective Traveler Schemes With Inactivated TBE Whole Virus Vaccine

Study Overview
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Brief Summary
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The study aims to answer this question: whether adequate immunity can be achieved in a short time, that is, by a rapid immunisation process, using at least one of 3 new TBE immunisation schedules? The investigators will test the immunogenicity (the degree of immunity achieved) of each of the immunisation schedules at various times after the injections. If the results of this clinical study are positive, it may then be possible to develop the most successful immunisation schedule so that it can be used routinely. This means that the results of the clinical study have an enormous practical value in preventing TBE in people travelling or moving into areas with a high TBE risk.

Detailed Description
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The data from at least 99 individuals will be needed if the study is to draw reliable conclusions. One-third of these individuals will receive 3 injections in all: 2 on the first day and the third injection 4 days later (immunisation schedule 1). Another one-third will receive 2 injections in all: one on the first day and one injection 4 days later (immunisation schedule 2). The remaining one-third will also receive 2 injections, both of these on the first day (immunisation schedule 3). Participants will be assigned completely randomly (by chance) to one of these three groups. So each participant stands a 33% chance (a 1:2 chance) of receiving any one particular immunisation schedule. If you agree to take part, the process will be as follows: Brief Overview of the Course of the Clinical Study: Vaccination scheme 1 Vaccination scheme 2 Vaccination scheme 3 Vaccinations: I = Vaccination with FSME-IMMUN 0,5ml Scheme 1: 2 vaccinations at U1 (day 0), one injection into the left and the right upper arm each, 1 vaccination at U2 (day 4), injection into the left upper arm Scheme 2: one vaccination at U1 (day 0) and at U2 (day 4), injections into the left upper arm each Scheme 3: 2 vaccinations at U1 (day 0), one injection into the left and the right upper arm each

Official Title
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Clinical Study to Test the Immunogenicity of Variant Schedules for TBE Rapid Immunisation Using Inactivated TBE (FSME) Vaccine

Conditions
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Tick Borne Encephalitis

Intervention / Treatment
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* Biological: FSME vaccination (FSME-Immun)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: written informed consent FSME antibody level < 7IU/ml (ELISA), retrospective FSME antibody (IgG) < 63 VIEU/ml (ELISA), retrospective FSME antibody (IgM) negative FSME antibody inhibition capacity <1:10-retrospective available for the next 56 days Exclusion Criteria: age not 19 or over 65 pregnancy risk of becoming pregnant

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 65 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: Randomized
Intervention Model: Factorial Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1FSME vaccination<br>2 vaccination on day 0 | Biological: FSME vaccination (FSME-Immun)<br>* intra muscular 0.5 ml<br>* Other names: FSME-Immun 0.5 ml;|
| Experimental: 2 FSME vaccination<br>1 vaccination on day 0 and one vaccination on day 4 | Biological: FSME vaccination (FSME-Immun)<br>* intra muscular 0.5 ml<br>* Other names: FSME-Immun 0.5 ml;|
| Experimental: 3 FSME vaccination<br>2 vaccinations on day 0 and 1 vaccination on day 4 | Biological: FSME vaccination (FSME-Immun)<br>* intra muscular 0.5 ml<br>* Other names: FSME-Immun 0.5 ml;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| achievement of FSME-Antibody-level (IgG) >25IU/ml at visit U2, U3, U4, U5, U6, U7, U8 and U9-yes/no achievement of FSME antibody-level (IgG) of >126VIEU/ml at U2, U3;U4, U5, U6, U7, U8 and U9-yes/no |  | U2 (=day4) U3 (=day7) U4 (=day10) U5 (=day 14) U6 (=day21) U7 (=day28) U8 (=day42) U9 (=day56) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| FSME antibody level at U2, U3, U4, U5, U6, U7, U8 and U9 |  | U2 (=day4) U3 (=day7) U4 (=day10) U5 (=day 14) U6 (=day21) U7 (=day28) U8 (=day42) U9 (=day56) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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encephalitis, FSME, central european encephalitis