Protective immunization against Treponema pallidum using specific immune complexes--an attempt.

Rabbits were immunized using isolated and dissolved specific immune complexes obtained from patients suffering from early syphilis. After immunization the rabbits were infected intradermally with living Treponema pallidum. Some of them did not develop lesions at the infection sites. In comparison to controls there was a delayed and reduced production of antibodies. The effect of immunization may be induced by a treponemal protein antigen as a constituent of the specific immune complexes.