Dr. Slotkowski's comments on the lack of unanimity in terminology for the newly recognized complication of cowpox vaccination summarizes many important factors.
However, the cases with prolonged vaccinia represent more than an unfortunate and interesting complication of a minor office procedure. They are a "window" through which some of the fragments of the immune mechanism can be seen. At least 5 different types of defects have been recognized and not all are present in every case.