[Immunity aspects in syphilis].

Until lately, the host-parasite relationship in syphilis registered a certain latency because of the difficult approach to the problem and especially because of the enthusiasm caused by the possible eradication of the disease by penicillin. As these expectations were not confirmed, attention was again focussed on study by modern means of the biology of pathogenic treponema, its antigenic properties, possibility of in vitro cultivation and certain humoral and cellular immune aspects that govern the evolution of the disease and, probable, the acquiring of specific immunity. The attempts made for obtaining a live vaccine, attenuated by irradiation and experimented in animals, appear to foreshadow the possible use of this vaccine in the near future in man.