Vaccines for smallpox have been delivered to the skin dating back to Edward Jenner's first experiments in 1796 demonstrating that exposure to cowpox could protect against smallpox infection. A variety of scarification techniques and devices have been used to allow virus introduction, including knives, needles, scalpels, and rotary lancets. During the global smallpox eradication campaign, both multi-dose nozzle jet injectors and bifurcated needles were used for ID vaccinia virus inoculation (Henderson et al. 2008 ).