Vaccines and the Looming Threat of Syphilis

During the past several decades, syphilis has increased in the US and explosively so in China and Russia.While most current cases can be cured by penicillin or second line antibiotics, strains of the syphilis spirochete (Treponema pallidum) resistant to the latter have emerged.And the potential of strains to acquire resistance to penicillin via plasmids has recently been recognized.The 36 million-plus undertreated cases of syphilis in the world represent metaphorically a vast global 37°C incubator allowing exchange of antibiotic resistant genes among the human-borne bacteria and theoretically permitting the emergence of penicillin resistant strains.None has yet been identified but they seem inevitable along with the threat of multi-resistant strains. There is now concern over the lack of new antibiotics to succeed the penicillins.Since such new drugs would likely require a decade or so of research and federal approval, vaccine-based protection is of immediate consideration here.This approach may exploit the new knowledge about the biology of T. pallidumstrainstheir many complex antigens, serotypes, and the latter’s distribution in populations. Equally important are recent insights into immunology, such as cellular aspects and antigenic competition