Liposomes as a Vaccine Delivery System

Among the various particulate delivery systems, liposomes—bubble-like nano/microsized lipidic bilayer structures—have shown great promise as an antigen-carrying vehicle. Few liposomal vaccines have been introduced to the market. The key advantages of liposomes as a vaccine delivery system are their ability to protect antigens against degradation, carry single or multiple hydrophilic and lipophilic antigens, control the release of antigens, enhance cellular uptake, and improve antigen-specific immune responses. Physicochemical properties of liposomes such as size, charge, and membrane fluidity can be modified to improve their ability to target antigen-presenting cells. Understanding how the different physicochemical properties of liposomes affect the overall immune response is important for the development of successful liposome-based vaccines. This chapter discusses the use of liposomes as vaccine carriers, the impacts of formulation parameters on liposome-mediated immunity, the different types of liposomes, and their manufacturing perspectives from the bench to large scale.