[Active vaccination against early summer meningoencephalitis].

TBE is a rather rare disease (incidence in Switzerland 0.46/1,000,000 population per year). Acquisition occurs only in well known endemic areas through bites of infected ticks. The course of the disease is not trivial: 0.5-2% of cases are fatal, 2.7% have persistent serious paralysis and some 33% a postencephalitic syndrome. There is no specific therapy. An active vaccine is commercially available which is reliably immunogenic (99% of vaccinated persons develop protective antibodies) and involve only a few mild side effects. Mass vaccination seems not to be cost-effective but would be epidemiologically efficient, as a vaccination campaign in Austria has shown. Because of the increasing importance of leisure-acquired TBE infections, the Swiss recommendations could be formulated more liberally: active vaccination is recommended for everyone who regularly spends time in forests in an endemic area, be it for work or leisure.