Skin abrasion using an abrasive paper is perhaps the most commonly used method of disrupting the stratum corneum for immunization. For example, abrasion with emery paper, after skin hydration, has been shown to induce adequate penetration of anthrax vaccine (Matyas et al. 2004 ) and influenza virus vaccine (Guebre-Xabier et al. 2003) , among others. This has led to the development of a Skin Prep System (SPS) to provide a controlled method of stratum corneum disruption for transcutaneous immunization currently under development by Intercell (Frerichs et al. 2008) (Fig. 4a ). This technique has been shown to be effective in humans. Specifically, the skin was prepared by use of two mild strokes with the skin preparation device containing a mild abrasive affixed to a pressure-controlled device. The device was a single-use, disposable system and was discarded immediately after use. Following skin preparation, the patch containing vaccine against traveler's diarrhea (LT patch) was applied within the marked area and worn for 6 h at each vaccination, then removed and discarded by the participant. 59 LT-patch recipients were protected against moderate-to-severe diarrhea (protective efficacy of 75%) and severe diarrhea (protective efficacy of 84%). LT-patch recipients who became ill had shorter episodes of diarrhea (0.5 vs 2.1 days) with fewer loose stools than placebo . In another study, a similar technique was used to boost response against influenza vaccine. In this case, prior to application, the patch area was lightly abraded with ECG-grade emery paper on skin wetted with 10% glycerol/70% alcohol to disrupt the stratum corneum. In weeks following vaccination, hemagglutination inhibition (HAI) responses in LT immunostimulatory patch recipients showed improvement over those receiving vaccine alone (Frech et al. 2005) .