SINCE 1961 when the oral poliomyelitis vaccines were first made available for general use in the United States, scattered cases of paralytic disease have occurred in association with these vaccines. Many of the cases have been clinically indistinguishable from poliomyelitis. Epidemiologically, the pattern of their occurrence has raised the possibility that some may have been caused by the vaccine.
In 1962 when the existence of this problem was first appreciated, the Surgeon General of the Public Health Service convened a special advisory committee which met on a number of occasions between August and December. The Committee reviewed in detail reported cases of paralytic disease occurring within a period of 30 days following ingestion of the oral poliomyelitis vaccines. The Committee concluded that 18 cases of paralytic poliomyelitis were "compatible with the possibility of having been induced by the vaccine." Of these, 11 followed type III vaccine and 7 followed type