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)

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.