Inoculation Syphilis in Human Volunteers

Segregation of B and T Cell Epitopes of Treponema pallidum Repeat Protein K to Variable and Conserved Regions During Experimental Syphilis Infection

“…The Ab response directed to variable regions of TprK may help explain the lack of heterologous protection in rabbits and humans (5,6), as heterologous isolates do not have identical TprK variants (11). Another protein with similar discrete variable regions, C. trachomatis MOMP, has been implicated in conferring strain-specific immunity in humans (28).…”

“…How these treponemes are able to escape the robust immune responses, invade a wide range of tissues, and persist is largely unknown. It is also unknown why infection-induced homologous protection in the rabbit model does not protect against heterologous isolates (5) and why humans can be infected multiple times (6).…”

Syphilis: using modern approaches to understand an old disease

“…Individuals with lesions of early syphilis are most likely to transmit T. pallidum. While the risk of infection in exposed individuals is approximately 30% (range, 10%-80%) (4)(5)(6), inoculation studies with the Nichols strain of T. pallidum suggest that the intradermal ID 50 is only 57 organisms (7). The natural history of T. pallidum infection is summarized in Figure 1.…”

Ethical Failures and History Lessons: The U.S. Public Health Service Research Studies in Tuskegee and Guatemala

“…25,26,31,32 Even when a major review of inoculation studies was published in 1956 with Cutler as one of the authors, the study in Guatemala remained unmentioned. 33 While anecdotal evidence suggests rumors about this study had circulated within the U.S. Centers for Disease Control and Prevention (CDC) for years, until I brought it their attention in 2010 it remained unacknowledged. (For details on how the story made its way through the CDC and on to the White House, see Reverby 2010.…”