[Polio vaccination today: critical remarks].

Vaccination against poliomyelitis remains an absolutely mandatory measure to prevent resurgence of this dreadful viral infection. Today, however, when the chance to get infected is extremely low, one has to reconsider much more the inherent risk of such a living vaccine which is principally able to induce neurologic disease especially in immunocompromised host the number of which is increasing in our population. Since these attenuated vaccine strains multiply largely in the orointestinal tract of a vaccine, those viruses are shed and easily spread into surroundings so that other persons which are not aware of this event are exposed. But also in normal hosts the vaccine strains are able to produce disease because the genetic mutation leading to reduced virulence is not absolutely stable. Back mutations with increased virulence develop during multiplication in the vaccinee and may threaten the vaccinee as well as contact persons. For the sake of security these consequences should be respected much more. Since a dead vaccine of polioviruses is available, one should much more often profit from this choice.