TABLE 1.

Challenge results

ImmunogenNo. of DF+ lesions/total (%)aP valuebNo. of ulcerative lesions/total (%)P valueb
Fragment 18/32 (25)<0.00112/32 (37.5)<0.001
Fragment 222/24 (91.7)>0.0516/24 (66.7)<0.001
Fragment 327/32 (84.4)<0.02518/32 (56.3)<0.001
None32/32 (100)32/32 (100)
  • a Aspirates were taken from lesions and examined under a dark-field microscope for the presence of treponemes.

  • b Chi-square test comparing test values to unimmunized-control values.