Infectious tolerance describes an in vivo process in which tolerance is passed on from one population of lymphocytes to another. In this way, short-term therapy aimed at generating infectious tolerance has the potential to achieve long term, self-perpetuating immune homeostasis in a clinical setting. In recent years, a number of differing strategies have successfully achieved tolerance in vivo. These include harnessing regulatory T cells and tolerogenic antigen presenting cells, promoting tolerogenic interactions or inhibiting activation of effector cells. Many of these are just beginning to face the harsh realities of the therapeutics industry.