[Prevention of tick-borne encephalitis (TBE)].

Active immunization is the only reliable means of preventing TBE. Evidence suggests that effectiveness is greater than 95%. Breakthrough infections in fully immunized individuals, however, do occur. Recent data indicate that the duration of protection following basic immunization is substantially longer than previously appreciated. The vast majority of vaccinees are still seropositive > or = 8 years after the last dose. Thus, the current practice of administering booster doses every 3 years is a topic of intense debate. Until it is resolved, patients can be offered the determination of a serum anti-TBE IgG titre as an alternative to "blind" administration of a booster dose. It has recently been shown that seropositivity determined by some commonly used commercial ELISA tests correlates closely with the presence of protective antibody. In Switzerland, TBE vaccination is currently recommended for individuals older than 6 years of age who frequently dwell in endemic areas. Since 2005, health care insurances are required to cover for costs incurred by immunization according to these recommendations.