Research status and perspectives for pathogenic spirochete vaccines.

Leptospira interrogans, Borrelia burgdorferi, and Treponema pallidum are important pathogenic spirochetes. The incidence of human diseases caused by pathogenic spirochetes, e.g., leptospirosis, Lyme disease, and syphilis, has been recently increased, posing a threat to public health. Mechanisms of spirochete pathogenicity are not yet fully understood, and no safe and effective vaccine to prevent and control the infection by pathogenic spirochetes is currently available. In this article, we review the progress of research into the pathogenic spirochete vaccine, mainly in terms of vaccine types. The development of relevant vaccines against pathogenic spirochetes has generally proceeded via several stages, such as the whole-cell inactivated vaccine, live attenuated vaccine, and gene-engineered vaccine, and will likely enter a new stage with the application of gene editing technology. In this review, we mainly summarized the types of pathogenic spirochete vaccines and conducted a preliminary analysis on the protective effect of immunity, and proposed a further prospect for the development of pathogenic spirochete vaccines.