AN IMMUNIZING STRAIN OF THE VIRUS OF POLIOMYELITIS.

In this communication we have described a strain of the virus of poliomyelitis derived from a rapidly fatal human case, which exhibits mild degrees of infective power and marked degrees of protective effect for the monkey. While Macacus rhesus displays perceptible differences in suceptibility to the attenuated virus, nearly all individuals respond to the inoculation and none succumbs to the infection induced. As compared with previously described examples of experimental poliomyelitis, the modified disease described in this paper is distinguished by its relatively benign nature and its tendency to end in recovery rather than, as with the earlier observed instances, in death.