Tick-Borne Encephalitis (TBE) Seropersistence After First Booster and Response to a Second Booster in Children, Adolescents and Young Adults (Follow-Up to Study 700401)

Pfizer

Status and phase: Completed; Phase 4

Conditions: Encephalitis, Tick-Borne

Treatments: Biological: FSME-IMMUN 0.25 mL Junior (1.2 µg TBE antigen/0.25 mL) or FSME-IMMUN 0.5 mL (2.4µg TBE antigen/0.5 mL)

Study type: Interventional

Funder types: Industry

Identifiers

NCT00894686

2009-009324-36 (EudraCT Number)

B9371021 (Other Identifier)

700802

Details and patient eligibility

About

The main purpose of this study is to assess the seropersistence of TBE virus antibodies in children, adolescents and young adults who received the first booster vaccination with either FSME-IMMUN 0.25 mL Junior or FSME-IMMUN 0.5 mL in precursor Study 700401.

Enrollment: 179 patients

Sex: All

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

Subjects who participated in precursor Study 700401 and meet ALL of the following criteria are eligible for participation in this study:

• Subject / parent(s) / legal guardian(s) provide(s) written informed consent (according to national law);
• Subject provides written assent to the study according to age and capacity of understanding;
• Subject received the first booster vaccination with either FSME-IMMUN 0.25 ml Junior or FSME-IMMUN 0.5 ml during the course of precursor Study 700401;
• Blood was drawn after the first booster vaccination in precursor Study 700401;
• Subject / parent(s) / legal guardian(s) understand(s) the nature of the study and is / are willing to comply with the requirements of the protocol (e.g. return for follow-up visits, completion of the Subject Diary).

Exclusion criteria

Subjects who participated in precursor Study 700401 and meet ANY of the following criteria are not eligible for participation in this study:

• Subject received any TBE vaccination since his / her first booster vaccination in precursor Study 700401;
• Subject has a history of infection with or vaccination against other flaviviruses (e.g. Dengue fever, yellow fever, Japanese B encephalitis) since his / her first booster vaccination in precursor Study 700401;
• Subject is known to be HIV positive since his / her first booster vaccination in precursor Study 700401 (a special HIV test is not required for the purpose of the study);
• Subject received a blood product or immunoglobulins within 90 days before any blood draw or in the period between the blood draw and the booster vaccination (as applicable);
• Subject has a known or suspected problem with drug or alcohol abuse (> 4 liters of wine/week or equivalent level of other alcoholic beverages);
• Subject / parent(s) / legal guardian(s) is / are in a dependent relationship with the study investigator or with a study team member. Dependent relationship includes close relatives (i.e., children or grandchildren, partner / spouse, siblings) as well as employees of the investigator or the site conducting the study.

Trial design

179 participants in 1 patient group

All subjects

Experimental group

Description:

Assessment of seropersistence of TBE antibodies at yearly intervals from approximately 3 years (38 months) to 10 years (118 months) after the first booster vaccination (in Study 700401), as well as antibody response to a second booster vaccination with either FSME-IMMUN 0.25 mL Junior or FSME-IMMUN 0.5 mL, depending on the subject´s age. Timing of the second booster vaccination will depend on the level of serum TBE antibodies detected at the defined assessment time points. Subjects who are not protected against TBE for an entire further season (NT titer \<= 20 and/or ELISA value \<=126 VIE U/mL) will be invited to receive the second booster vaccination at either the 40, 48, 60, 72, 84, 96, 108, or 120-month time point.

Treatment:

Biological: FSME-IMMUN 0.25 mL Junior (1.2 µg TBE antigen/0.25 mL) or FSME-IMMUN 0.5 mL (2.4µg TBE antigen/0.5 mL)