The change from obligatory to optional or recommended vaccination seems to be inevitable. With obligatory vaccination more than 90% of children are adequately vaccinated against diphtheria, tetanus, poliomyelitis and hepatitis B. In contrast, with an optional or recommended vaccination strategy, it is difficult to obtain control and eradication. At the present time, polio eradication is about 99% but to achieve total eradication will require a considerable organizational and economic investment. Surveillance of AFP (acute flaccid paralysis) indicates the state of polio eradication. Only by monitoring and prevention can we be sure that there is no circulation of wild poliovirus.