ABSTRACT
Vaccination is critical in the control of infectious diseases, but it frequently fails to eradicate certain refractory infections for which an effective vaccine is desperately sought but remains elusive. The generation of memory response and protection against infection are critical parameters in vaccination, while a significant issue is the effective delivery of antigen in an intelligent manner to elicit a robust immune response. In this regard, nanotechnology is making significant contributions to the development of effective vaccine adjuvants and delivery systems. These can shield the encapsulated antigen from the host’s in vivo environment while simultaneously releasing it in a sustained manner to induce a long-lasting immunostimulatory effect. This chapter summarizes nanoscale-based adjuvants and delivery vehicles such as viral vectors, virus-like particles (VLPs), and virosomes; non-viral vectors such as nanoemulsions, lipid nanocarriers, biodegradable and non-biodegradable nanoparticles, calcium phosphate nanoparticles (NPs), colloidally stable NPs, and proteosomes; and pattern recognition receptors such as c-type lectin. In many cases, failure to develop a vaccine is attributed to the candidates’ inability to elicit appropriate immune responses for establishing humoral as well as cellular immunity. Over the last few decades, NPs ranging in size from 10 to 500 nm, such as liposomes, inorganic or metal NPs, VLPs, emulsions, immune-stimulating complexes, and polymeric NPs, have been developed as a potential carrier for vaccines to stabilize and deliver the adjuvant and antigens, thus forming proper vaccine adjuvant-delivery systems.
