POLIOMYELITIS VACCINATION - WHAT ARE THE OPTIONS

Two vaccines are available to prevent poliomyelitis. They are inactiva ted poliovirus administered by injection (IPV, also known as Salk vacc ine) and live attenuated poliovirus administered orally (OPV, also kno wn as Sabin vaccine). The World Health Organization recommends OPV, be cause it suppresses the circulation of wild poliovirus and is relative ly inexpensive. About 80% of the world's children in the first year of life have been fed OPV and wild poliovirus is now disappearing from t he world. It has been entirely eradicated from the Western Hemisphere, so that presently there are no cases in the region and wild polioviru s can no longer be found. The single drawback of OPV is the occurrence of about 1 case of vaccine-associated poliomyelitis per 10(6) doses d istributed. IPV does not have this deficiency, and is still used in a few countries. A combination of IPV and OPV is used in Denmark, Israel , Gaza and the West Bank with excellent results (no polio cases and no circulation of wild virus), but this vaccine combination boosts the c osts of polio immunisation. However, once the virus can no longer be d etected in the world, a combination of IPV and OPV can be used for a s hort period to finish the job and the world can save millions of dolla rs each year by stopping vaccination, for there will be no wild poliov irus remaining.