Thermal poration of skin has been used to deliver vaccines into skin. Microporation systems are designed to porate the skin and are being developed by a number of companies. In this method, an array of micropores is created in the skin by removal of stratum corneum by the application of focused thermal energy based on resistive heating via the contact of electrically heated small-diameter wires to the skin surface (Bramson et al. 2003) (Fig. 4c ) or other methods based on radiofrequency or laser-based approaches. In this study, the microporation tip was comprised of a set of 80 lm diameter tungsten wires with control circuitry allowing for precise control of the electrical current pulses that were passed through each wire. The software user interface was designed to enable the control of various microporation parameters including micropore density, resistive element temperature, current pulse width, number of pulses, pulses pacing, and contact pressure. The temperature of the tip that was placed in contact with the skin was calibrated by an optical calibrator device. The study showed that microporation significantly increased the penetration of topically delivered vaccine. Microporation enhanced expression of luciferase upon placement of adenovirus vectors by 100-300-fold. The same procedure led to increased CTL response and increased IFN-c secreting cells. In a related study, the same technology has been shown to deliver influenza vaccine into mouse skin. Eighty micropores were created in 1 cm 2 area and the vaccine was placed on the porated skin. This procedure generated adequate protective response in mice (Garg et al. 2007 ).