Efficient nanoparticle-mediated needle-free transcutaneous vaccination via hair follicles requires adjuvantation

Trans-follicular (TF) vaccination has recently been studied as a unique route for non-invasive transcutaneous vaccination. The present study aims to extensively characterize the immune responses triggered by TF vaccination using ovalbumin loaded chitosan-PLGA (poly lactic-co-glycolic acid) nanoparticles without skin pre-treatment to preserve skin integrity. The impact of formulation composition i.e. antigenic solution or antigen-loaded nanoparticles with or without adjuvant [bis-(3′,5′)-cyclic dimeric adenosine monophosphate] on immune response quality following TF immunization was analyzed and compared with immune responses obtained after tape stripping the skin. The results presented in this study confirm the ability of nanoparticle based vaccine formulations to deliver antigen across the intact skin via the follicular route, but at the same time demonstrate the necessity to include adjuvants to generate efficient antigen-specific humoral and cellular immune responses.From the Clinical EditorThis study confirms the ability of nanoparticle based vaccine formulations to deliver antigen across the intact skin via the follicular route, and highlights the necessity to include adjuvants to generate efficient immune responses.

Graphical AbstractEasy to use, needle-free and efficient vaccination strategies are desperately needed to meet the current challenges of vaccine development. In this perspective, transfollicular vaccination aims to deliver antigens to the abundant peri-follicular APCs without compromising the SC barrier function. The present work clearly demonstrates the potential of nanoparticulate systems as an approach to deliver antigens as well as stimulating and modulating efficient humoral and cellular immune response across intact skin (without breaching the barrier system) provided co-administration of an adjuvant in the delivery system.Figure optionsDownload high-quality image (184 K)Download as PowerPoint slide