Oral poliomyelitis vaccine: time to change?

For 3 decades, vaccination against poliomyelitis has rested mainly on the use of the oral attenuated vaccine (OPV). In countries where wild type poliomyelitis has been successfully controlled by OPV, the rare cases of poliomyelitis that can still be identified occur in vaccinees or their contacts and are caused by vaccine related strains. Over years, data indicating that the inactivated vaccine (IPV) also has the potential to control poliomyelitis and that there are no known risks associated with the use of this vaccine have accumulated. The reasons for changes in vaccine policy in industrialised countries and the situation of the global effort of poliomyelitis immunisation are described. Some of the issues and challenges for the future are reviewed.