Modulation of immune responses with transcutaneously deliverable adjuvants

Transcutaneous immunisation is a novel vaccination strategy based on the application of antigen together with an adjuvant onto hydrated bare skin. This simple and non-invasive immunisation procedure elicits systemic and mucosal immune responses and therefore, it provides a viable and cost-effective strategy for disease prevention. For the induction of antigen-specific immune responses the use of adjuvants is critical. They potentiate and modulate the type of immune responses by stimulating the production of cytokines that drive the differentiation of T cells towards the Th1 or Th2-phenotype. These cells mediate protection against different infectious diseases and therefore, their selective induction is important for successful vaccination. In this review we give a brief overview of transcutaneously deliverable adjuvants and we discuss how they modulate immune responses to topically applied antigens.