Use of vaccinia virus in the treatment of metastatic malignant melanoma.

Of 19 patients with proved metastases from malignant melanoma treated by inoculations of smallpox vaccine, intradermal deposits disappeared completely in six out of ten cases. Five of these remained well 2 to 22 months after initial treatment. The response was limited strictly to the site of inoculation. The mechanism of action of vaccinia virus in malignant melanoma is not clear.