Tick-borne encephalitis (TBE) is a substantial public health problem in many 
parts of Europe and Asia. To assess the effect of increasing TBE vaccination 
coverage in Austria, we compared incidence rates over 40 years for highly 
TBE-endemic countries of central Europe (Czech Republic, Slovenia, and Austria). 
For all 3 countries we found extensive annual and longer range fluctuations and 
shifts in distribution of patient ages, suggesting major variations in the 
complex interplay of factors influencing risk for exposure to TBE virus. The 
most distinctive effect was found for Austria, where mass vaccination decreased 
incidence to ≈16% of that of the prevaccination era. Incidence rates remained 
high for the nonvaccinated population. The vaccine was effective for persons in 
all age groups. During 2000-2011 in Austria, ≈4,000 cases of TBE were prevented 
by vaccination.