Fig. 1. Schematic illustration of several transcutaneous antigen delivery technologies used for transcutaneous vaccination. (A) Patch, (B) E. coli vectors/Viral vectors, (C) Vesicular systems, such as liposomes, niosomes, transfersomes, and vesosomes, (D) Ultrasound, (E) Nanoparticles or Microemulsions, (F) Iontophoresis or Electroporation (G) Micro-needles/Nano-needles, (H) Cell penetrating peptide-conjugated proteins (I) Tape-stripping.
