THE PRESENT article was prepared at the request of the American Medical Association as part of the symposium on poliomyelitis. It represents the author's evaluation of published and unpublished data pertinent to the prophylactic use of gamma globulin in prevention of poliomyelitis. The chief sources of data are the four recently published papers of Dr. Hammon and his associates.1 The critical analyses and opinions of Dr. Alexander Langmuir, Dr. William Clark, Dr. Albert Sabin,2 Dr. Karl Habel,3 Dr. Harry Weaver, and others have been obtained through personal communication and carefully considered prior to preparing this discussion.
Inasmuch as many and varied hypotheses have been advanced concerning the epidemiology of poliomyelitis, it is first necessary to summarize very briefly the generally held epidemiologic concept of the natural occurrence of poliomyelitis, so as to bring our thinking onto common ground. Since the paralytic disease is of primary concern, it