An Extension Study to Determine the Persistence of Tick-borne Encephalitis (TBE)-Specific Antibody Responses Among Children and Adolescents Previously Immunized Against TBE

Study Overview
=================
Brief Summary
-----------------
This study will evaluate the durability of antibody responses in children and adolescents after primary immunization with TBE vaccine

Official Title
-----------------
A Phase IV, Open-label, Multi-center Follow-up Study to Determine the Persistence of Tick-borne Encephalitis (TBE)-Specific Antibody Responses Among Children and Adolescents Previously Immunized Against TBE

Conditions
-----------------
Tick Borne Encephalitis (TBE)

Intervention / Treatment
-----------------
* Other: Serology blood draw


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Healthy study subjects from the parent study who completed the primary vaccination series, with parental or legal guardian informed consent Exclusion Criteria: Subjects who did not receive complete schedule of primary vaccination in the parent study Subjects enrolled in other investigational studies at the same time and within the last three months Subjects with any condition which, in the opinion of the investigator, might interfere with the evaluation of the study objectives

Ages Eligible for Study
-----------------
Minimum Age: 4 Years
Maximum Age: 14 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Arm 1<br> | Other: Serology blood draw<br>* Blood draw only, no vaccine<br>|
| Active Comparator: Arm 2<br> | Other: Serology blood draw<br>* Blood draw only, no vaccine<br>|
| Active Comparator: Arm 3<br> | Other: Serology blood draw<br>* Blood draw only, no vaccine<br>|
| Active Comparator: Arm 4<br> | Other: Serology blood draw<br>* Blood draw only, no vaccine<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Analysis of immunogenicity (TBE neutralizing antibody levels) 3 years after vaccination |  | 3 years after vaccination | 
| Analysis of immunogenicity (TBE neutralizing antibody levels) 4 years after vaccination |  | 4 years after vaccination | 
| Analysis of immunogenicity (TBE neutralizing antibody levels) 5 years after vaccination |  | 5 years after vaccination | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Analysis of immunogenicity (TBE antibody levels as measured by ELISA) at 3 years after vaccination |  | 3 years after vaccination | 
| Analysis of immunogenicity (TBE antibody levels as measured by ELISA) at 4 years after vaccination |  | 4 years after vaccination | 
| Analysis of immunogenicity (TBE antibody levels as measured by ELISA) at 5 years after vaccination |  | 5 years after vaccination | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
TBE, Tick Borne Encephalitis