title: Attempts at immunization against syphilis with avirulent Treponemma pallidum.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000941:Antigens; D007114:Immunization; D008297:Male; D009113:Muramidase / Q000494:pharmacology; D011817:Rabbits; D013587:Syphilis / Q000517:prevention & control*; D014210:Treponema pallidum / Q000187:drug effects / Q000276:immunology*; D014465:Ultrasonics
chemical_list: D000941:Antigens; D009113:Muramidase