Universal use of inactivated polio vaccine.

OBJECTIVES To present an update on the status of poliomyelitis worldwide, number of cases per year, regions most affected by the disease, vaccines currently available, their risks and benefits, monovalent vaccine use, risks of disseminating a mutant virus in the community, progress that has been made in terms of worldwide eradication and the World Health Organization's (WHO) proposals in this transition period between global eradication and the post-eradication period. SOURCES OF DATA Data for the period from 1955 to 2005 were searched in MEDLINE, LILACS, The Web, Doctor's Guide, WHO website and the Pan American Health Organization (PAHO) website and text book. SUMMARY OF THE FINDINGS In 1988, the WHO established the goal of eradicating the disease and interrupting transmission of the wild virus globally. Since then, there has been a dramatic decline of the disease, although in 2005 there were still some countries considered endemic and others where polio returned on account of imported viruses. The vaccines used worldwide are the classical tOPV and IPV, and in this eradication process, the use of mOPV vaccines has been encouraged in places where only one type of poliovirus circulates. In addition to spreading the virus in the community, the OPV vaccines may, however, cause paralyses by reversal of the neurovirulence process. CONCLUSIONS For a world free of poliomyelitis disease, it would be necessary to interrupt circulation of the virus, which will only be possible if the OPV virus were to be discontinued, in accordance with the WHO proposals for this transition period and the post-eradication period.