Trivalent Poliomyelitis Vaccine Administered Orally in a Cloistered Community

DURING the ten-year period since the first patient was deliberately fed a culture of attenuated poliomyelitis virus1 until the present time, probably more than 10,000,000 human beings have been fed a similar culture of poliovirus or mixtures of polioviruses. Moreover, numerous other such immunization programs are being instituted in much of the Western world, indicating the relative, if not utter, safety of such procedures. Despite some laboratory evidence to the contrary,2 the theoretical possibility of reversion to virulence has not been observed as a clinical phenomenon. Most of the published observations have been made among children and young adults, especially . . .