An experiment is reported in which was studied the effects of a concomitant vaccinal infection and of vaccinal immunity upon the reaction to syphilis in rabbits induced by intracutaneous inoculation.
The results obtained showed that the reaction was modified by both conditions. A vaccinal infection initiated at the time of syphilitic inoculation was associated with a defensive reaction of lessened efficiency, the ensuing syphilis being more severe than in control animals. A state of vaccinal immunity present at the time of syphilitic inoculation was associated with a reaction of heightened efficiency, the ensuing syphilis being very mild.
These results are in harmony with those obtained in other experiments in which the intratesticular route of syphilitic inoculation was employed.