[New answers to the questions of continued rabies control in Germany].

With the assistance of a computer simulation model changed rabies spreading in immunised fox populations is examined. The influence of long-time and large-scale vaccination on the virus-host-system is analysed and new effects and their causes are shown. Rabies can persist for many years despite continuous vaccination with high immunisation rates. Because of the characteristic low-level prevalence the disease is provable by random only without using untreatable surveillance measures. Therefore one has to keep in mind the possibility of continued rabies within areas suspected rabies-free by surveillance. Consequences for emergency programs after termination of the vaccination will be discussed.