Freed D L, Eyres K E
Br J Dermatol. 1979 Jun;100(6):731-3. doi: 10.1111/j.1365-2133.1979.tb08081.x.
Severe warts of 20 years duration, highly resistant to therapy, were found to contain a soluble factor which blocked the local expression of cellular immunity, without affecting systemic immune responsiveness. This finding enabled us to propose therapy by infection, and this had a limited success.