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Oral polio vaccine (OPV) is recommended for routine immunization in the United States in part because of its ability to induce intestinal and pharyngeal immunity to reinfection. Mucosal immunity produced by OPV and enhanced-potency inactivated polio vaccine (E-IPV) was compared by challenging vaccines with type 1 OPV. Fewer OPV (25%) than E-IPV (63%) vaccinees excreted OPV virus in stool after challenge. The mean stool virus titer was higher and the duration of shedding longer among E-IPV excreters. Only one E-IPV and three OPV vaccinees shed virus in the pharynx after challenge. Prechallenge serum neutralizing antibody levels were not statistically different among E-IPV vaccinees who did and did not shed virus; these levels were much higher than those of OPV vaccinees. Poliovirus-specific IgA levels in stool did not correlate with viral excretion. E-IPV was less effective than OPV in preventing and limiting intestinal infection, even though it induced higher postvaccination serum antibody levels.

Adults who travel to areas where poliovirus is endemic or epidemic have a statistically small yet potentially important risk of exposure to wild poliovirus. Vaccination is recommended for persons at risk of acquiring poliovirus infection. The vaccination schedule depends on the time remaining before departure and the patient's immunization status.

Since 1974, greater than 100 different surveys have been carried out throughout the developing world to estimate the prevalence of lameness due to poliomyelitis. Reported prevalence rates have ranged from less than 1 to a high of 25 per 1,000 children surveyed and have prompted many countries to undertake polio vaccination programs. A review of surveys conducted to date reveals considerable variation in both the choice and use of survey methods and in the assumptions made in the analysis and interpretation of findings. More precise and comparable data about the risk of poliomyelitis could be obtained in future surveys by incorporating a standard case definition, by using house-to-house case-finding methods in representative community-based samples, by analyzing and presenting rates in more clearly defined ways, and by selecting stable populations for study.