Needles hurt. Worse, they can spread disease. PowderMed's new vaccine gun, the PMED, requires no sharps. The flashlight-shaped device relies on pressurized helium to shoot microscopic DNA vaccine particles just below the skin's surface at 1,500 miles an hour. The shot is painless because it hits just above nerve endings, where immunity-producing cells gather in large numbers. As a result, the PMED requires one thousandth the dose of a needle injection&8212;a major cost savings. And the powders don't need a fridge, so they're easier to store and transport. Vaccine powders for influenza and hepatitis are in the works.
source:
http://www.popsci.com/popsci/bown2005/p ... drcrd.html
