Immunity to poliomyelitis: situation in northern Italy and in some other European population groups.

The aim of the program to eradicate poliomyelitis is expected to be achieved in the space of very few years and therefore, as they approach this goal, countries find themselves faced with various problems to be tackled. Among these is the decision about how and when to stop polio vaccination, which also depends on seroepidemiological evaluations, necessary because of the possible persistence of circulating strains of poliovirus of vaccine origin which might continue even after the suspension of vaccination. For this reason, the results of seroepidemiological surveys carried out in some European countries in different periods of time and on various samples of the population are discussed.