Tick-Borne Encephalitis in Vaccinated Patients: A Retrospective Case-Control Study and Analysis of Vaccination Field Effectiveness in Austria From 2000 to 2018.

The FE of TBE vaccination is excellent. The observed higher proportion of severe disease in vaccinated persons with TBE does not reflect a higher risk associated with vaccination but is rather due to a somewhat lower FE against severe TBE. Because this effect was more pronounced in children, we recommend adapting the immunization schedule.