DURATION OF IMMUNITY FOLLOWING SMALL-POX VACCINATION

A certain degree of reticence is felt about recording observations on the subject on which so much work has been done and with which I have had a relatively short experience. The collection of the present data, however, was prompted first, by the observation made in a larger series of cases that successful revaccination after relatively short intervals is met with surprising frequency, and, second, the variance of my results with the ideas commonly held by physicians with whom I have come in contact. In dealing with patients reporting for compulsory vaccination, and who have a certain degree of antipathy to being inoculated, not infrequently objections are offered based on statements alleged to have been made by physicians by whom they have been previously vaccinated. If the patient has an unusually sore arm not only he, but sometimes his physician as well, is inclined to believe that a permanent protection