Abstract
Only a small fraction of any administered drug, including a vaccine, reaches its intended target tissue or cells. Homing vaccines to antigen-presenting cells (APC), where they can do their magic, has been the focus of attention for several decades. Since they are equipped with proper co-stimulatory signals, only professional APC are able to correctly process antigens and stimulate T and B cells to mount specific immune responses. With advances in the fields of modern immunology and nanotechnology, the new vaccine delivery platforms are emerging. APC-targeted vaccine delivery is required to elicit protective immunity, to reduce manufacturing costs, to minimize unanticipated effects of vaccines caused by off-target effects (thus reducing immunosuppressive mechanisms and toxicity), and to dramatically increase immunization efficacy. Indeed, in vivo targeting of APCs may represent the best hope for the generation of strategies leading to a personalized immunization without the need of expensive and complex ex vivo manipulation of patients’ PBMCs. Here, we will review and compare novel approaches on nanoparticle-based-targeted vaccine platforms, evaluating their molecular mechanisms of action, their translation ability, their efficacy, and their cost.