Oral delivery of poly(lactide-co-glycolide) encapsulated vaccines.

The induction of mucosal immune responses by oral delivery of vaccines is highly desirable. However vaccines to be used in this context will require protection from degradation in the gut and the use of specialised vehicles for their delivery and presentation. Using the biodegradable and biocompatible polymer, poly(lactide-co-glycolide), we have encapsulated bacterial and viral proteins, synthetic peptides and plasmid DNA in microparticles, and compared the immune responses resulting from their oral and parenteral administration to mice. The successful induction of specific systemic and mucosal humoral immune responses, as well as cell-mediated immune responses, demonstrates the potential of this polymer formulation as a vehicle for the oral delivery of vaccines.