Abstract
Vaccines are primarily employed for triggering the acquired immune response of the body to combat against diverse pathogenic organisms. Conventional approaches for vaccine delivery possess multiple challenges for effective delivery owing to lack of potential for targeting ability to a particular antigen and protection of antigens from physiological environments of body. In the past a few decades, nanocolloidal carriers have gained higher attention in vaccine delivery due to advantages of targeting ability, reduced immunogenicity and significant augmentation in immune response. Instances of colloidal carriers employed for vaccine delivery include liposomes, niosomes, microspheres, proteosomes, virosomes and virus like particles, reconstituted influenza viruses, immunostimulating complexes, antigen cochleates, etc. Further, surface engineering of these carriers with ligands, functional moieties and monoclonal antibodies has yielded enhanced immune recognition potential to the vaccine antigens for eliciting immune response by promoting differentiation of the antigen specific memory T-cells. In a nutshell, the present review provides an updated and exhaustive account on the recent advancements in various colloidal delivery systems employed for vaccine delivery outlining their potential applications, mechanism of augmenting the immune response and instances of the products existing in market in an explicit manner.