No poliovirus vaccines can be expected to eliminate the paralytic poliomye.litis that is caused by nonpolio enteroviruses or the cases that have been and continue to be diagnosed erroneously as paralytic poliomyelitis. Polioviruses have been recovered from the feces of patients with paralytic disease that is definitely not poliomyelitis, and very rare cases of so-called “vaccine-associated” paralytic disease cannot be regarded as having been caused by the vaccine virus when it is present in the feces and even more so when no virus is recovered. Surveys for residual poliomyelitis paralysis in tropical countries indicate an average annual incidence that is as high or higher than in the United States in the prevaccine era. Oral poliovirus vaccine has eliminated paralytic poliomyelitis caused by polioviruses in many temperate-climate countries in which a large proportion of children remain unvaccinated or incompletely .vaccmated: Oral poliovirus vaccine can also eliminate paralytic poliomyelitis from tropical countnes but a different strategy is needed for using the vaccine.