A physician has had recurrent herpes simplex for nineteen years. For the first twelve years it was localized to the shaft of the penis; for the last seven, to the right buttock. The attacks never occurred more often than two or three times a year. The last attack subsided April 5, 1947. On April 13 this physician began vaccinating patients. (The Department of Health of New York City recommended that all the population receive cowpox vaccination at once.) Four days later this physician had another attack of herpes on the same buttock, this lesion being about 1 inch (2.5 cm.) from the location of the last. The physician himself had not been vaccinated at this time.
It is impossible for one giving many vaccinations to avoid receiving some of the vaccine lymph on his fingers, without local reaction. It is statistically reasonable, in view of this nineteen year history, to