Encephalitis, Tick-Borne
Conditions
Keywords
tick-borne encephalitis
Brief summary
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.
Interventions
Subjects receive one vaccination with either FSME-IMMUN 0.25 ml or FSME-IMMUN 0.5 ml, depending on their age.
Sponsors
Pfizer
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
3 Years to 18 Years
Healthy volunteers
Yes
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 in another Baxter vaccine study within the last six months (with the exception of follow-up studies) Subjects will not be eligible for booster vaccination if they: * Do not meet the inclusion /
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| 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 | TBE virus antibody tests at pre-determined intervals with the last test at 21-35 days after the booster vaccination in this study |
Countries
Austria, Germany, Poland
Outcome results
None listed