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

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