"SERUM TREATMENT OF ACUTE POLIOMYELITIS"

To the Editor:—  It has been generally overlooked that the advocacy of convalescent serum in therapy was probably based on a misconception. Because convalescent serum neutralized poliomyelitis virus in vitro, it was assumed that it would do so likewise in patients, without considering the time interval and the probable fixation of virus in the nervous tissue. In practically every region where poliomyelitis prevails, the disease was first recognized after paralysis had developed, and only later was it realized that diagnosis was possible during the preparalytic phase and that there was also a nonparalytic type. When serum treatment was instituted the results seemed almost uniformly favorable, since the ratio of the preparalytic to the nonparalytic could not be determined prior to treatment, nor could there be reliable knowledge of the incidence of unreported illness in the community that might have been due to unrecognized nonparalytic poliomyelitis.Harmon's review, to which reference