Extracellular vesicle-based vaccines: A promising approach for parasitic diseases.

The development of vaccines to prevent diseases caused by parasites is urgent. Current treatments are highly toxic and ineffective. In addition, these diseases are more prevalent in vulnerable populations and can be fatal in children and immunocompromised individuals. Vaccines for parasites are a challenge in several aspects, including their complex life cycle and mechanisms of evading the immune response. Extracellular vesicles (EVs) are particles released by cells that carry different biomolecules, thus participating in cell-cell communication. EVs released by parasites play a role in the parasite-host interaction. Parasite molecules carried by EVs interact with host immune cells, activating or modulating their function. Thus, unraveling the role of these EVs in immunity could contribute to the identification of molecules with vaccine potential, leading to the development of EV-based vaccines to prevent parasitic diseases. In this chapter, we will discuss the main studies and findings on the protective role of parasite-derived EVs in vaccine preparations.