The purpose of this study is to assess the seropersistence of TBE antibodies in children and adolescents aged 1 to 15 years at the time of their first vaccination, 24 months and 34 months after completion of primary immunization with FSME-IMMUN 0.25 ml (3 vaccinations during the predecessor study 209), as well as the immune response to a booster vaccination with FSME-IMMUN 0.25 ml or FSME-IMMUN 0.5 ml administered 36 months after the third vaccination (in Study 209).
Protocol amendment of October 2006: The study has been prolonged for children and adolescents who still showed highly positive TBE virus antibody concentrations at approximately 3 years after the third vaccination and therefore did not receive a booster vaccination at this time point. Further follow-up of TBE antibody persistence is now included for these subjects at 46 and 58 months after the third vaccination (in Study 209), as well as a booster vaccination offered at either 48 or 60 months after the third vaccination (in Study 209), depending on individual TBE antibody levels.
Who can participate
Age range
3 Years – 18 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* Participated in Baxter study 209 and:
* They and/or their parents / legal guardians understand the nature of the study and agree to its provisions
* Written informed consent is available from the parents / legal guardians according to national law
* Written informed assent is available from the child/adolescent according to age and capacity of understanding
* They received the third vaccination with FSME-IMMUN 0.25 ml during the course of Baxter study 209
* Blood was drawn after their third vaccination during the course of Baxter study 209
* They showed an ELISA concentration \> 126 VIE U/ml and / or a NT titer \>=10 after the third vaccination in Baxter study 209
* They or their parents / legal guardians agree to keep a Subject Diary
Exclusion Criteria:
* Received any TBE vaccination since their third vaccination with FSME-IMMUN 0.25 ml
* Have a history of infection with or vaccination against other flaviviruses (Dengue fever, yellow fever and / or Japanese B-encephalitis virus) since their third vaccination with FSME-IMMUN 0.25 ml
* Are known to be HIV positive (a special HIV test is not required for the purpose of the study) since their third vaccination with FSME-IMMUN 0.25 ml
* Received a blood transfusion or immunoglobulins within 30 days of the first and second blood draw (as applicable)
* Have a known or suspected problem with drug or alcohol abuse (\> 4 liters wine / week or equivalent level of other alcoholic beverages)
* Have participated i…
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Seropositivity rate measured by ELISA and/or NT according to Adner et al., 2001 at each available time point after the third vaccination in study 209 and separately at each available time point after the booster vaccination in this study
Timeframe: TBE virus antibody tests at pre-determined intervals with the last test at 21-35 days after the booster vaccination in this study