Vaccination schemes are similar for both TBE vaccines. In clinical studies in adults and children, subjects who received the 3 doses of the primary vaccination course with the same brand showed similar seropositivity rates compared CHIR-99021 in vivo to subjects who received the third dose of the other brand

[6], [7], [8] and [9]. Clinical practice, as reflected by the queries of general practitioners and pediatricians to the marketing authorization holder (Baxter), has shown that incomplete and/or irregular vaccination histories are frequently encountered in both residents of and travelers to endemic geographies. Guidelines on how to proceed with the TBE vaccine FSME-IMMUN in subjects with an irregular and/or incomplete TBE vaccination history are therefore imperative but the body of evidence on the immunological effects of irregular TBE vaccination in both adults and children is scarce [10] and [11]. Different strategies are followed in current practice: (1) restart of the basic vaccination course, (2) measurement of the serum anti-TBE antibody concentration

to support the decision on the further vaccination schedule, or Osimertinib (3) administration of one or more catch-up vaccinations followed by continuation of the recommended schedule. The aim of this study was to generate a data basis reliable enough to derive practical recommendations on how to continue vaccination with FSME-IMMUN in subjects with an irregular TBE vaccination history. For this reason, the antibody response to a single

catch-up dose of FSME-IMMUN in irregularly vaccinated subjects because ≥6 years of age was assessed in an open manner. The study was conducted from May 1, 2005, to December 31, 2006 and was designed in accordance with the Recommendation on the Planning and Conduct of Post-authorization Observational Studies issued by the German Federal Institute for Drugs and Medical Devices [12] as a post-authorization multi-center open-label non-interventional study in individuals with irregularity patterns of their TBE vaccination histories. The study was carried out in accordance with the Declaration of Helsinki. The study protocol was reviewed and approved by five independent ethics committees. Healthy subjects ≥6 years of age (for details of the inclusion/exclusion criteria see supplementary data) with an irregular TBE vaccination history as depicted in Table 1 were eligible. Participation in the study included two visits: At the first visit written informed consent was obtained. Then a blood sample was drawn and the catch-up vaccination was administered (FSME-IMMUN Junior 0.25 ml in subjects ≥6 to <16 years of age, FSME-IMMUN 0.5 ml in subjects ≥16 years of age). The second visit was scheduled 3–12 weeks after the catch-up vaccination to obtain a second blood sample.