Despite the ubiquity and severity of parasitic diseases and our desire to prevent them, there are no effective antiparasitic vaccines in widespread clinical use. This review focuses on strategies for development of a vaccine against cutaneous leishmaniasis as a representative parasitic disease of paramount interest to dermatologists and all who care for patients who live in or travel to the developing world. Any effective strategy will require attention to the central role that host innate immunity plays during induction of durable resistance to these virulent protozoa. The cell types, receptors, and molecules of the innate immune system that will likely play a role in any effective vaccine against cutaneous leishmaniasis are reviewed.
The problem of vaccines for parasites: cutaneous leishmaniasis as an example
Despite advances in understanding of their epidemiology, vector ecology, disease pathogenesis, and treatments, parasites continue to ravage humanity. Unlike many viral and bacterial illnesses, there remain no effective and safe vaccines for parasitic illness in widespread use. The economics of private sector drug and vaccine development likely contribute to the relative neglect of parasitic diseases. Increased attention to these neglected tropical diseases in the public and nonprofit sectors has also not yet led to parasite vaccines. Technical challenges and the complexity of immunity to parasites clearly contribute to the absence of vaccines. The history of attempts to vaccinate against cutaneous leishmaniasis may be 1000 years old. Progress, controversy, and challenges in Leishmania vaccination have been reviewed previously. In this review, we examine the specific role that innate immunity plays in past and future leishmania vaccination strategies.