A Potent Vaccine Delivery System: The Promise and the Challenge

A vaccine typically contains an agent that resembles a live attenuated or killed pathogen, its toxins or surface proteins. It stimulates the body's immunity to recognize the agent as foreign, destroy it, and "remember" it, so that the immune system can Successfully defend the body from later encounters. Vaccines are now being delivered through carriers, adjuvants to enhance the recipient's immunological response to a supplied antigen, while keeping the injected foreign material to a minimum, this eliminates the need for booster doses. Adjuvants can act as a depot for the antigen thus leading to their sustained release and targeting. This paper reviews liposomes, microspheres, nanoparticles, dendrimers, micellar systems, ISCOMs, plant-derived viruses and needle-free technologies used to administer the vaccines.