This invention includes fusion proteins comprising a bacterial ADP-ribosylating exotoxin (bARE), or a variant or portion thereof, fused to a STa exotoxin, or a portion or variant thereof. Optionally, the exotoxins are fused via a peptide linker. The invention also includes compositions formulated for transcutaneous immunizations and/or induction of an immune response by epicutaneous administration comprising an effective amount of a fusion protein comprising a bacterial ADP-ribosylating exotoxin fused to a STa exotoxin. Optionally, the exotoxins are fused via a peptide linker.