 - Researchers are investigating the use of DNA vaccines to treat various types of cancer by provoking an immune system response to tumor cells. DNA vaccines mimic the effect of normal vaccines given to prevent infectious diseases, but they have been less effective than anticipated in humans. To improve the effectiveness of DNA vaccines, researchers are studying alternate delivery methods, such as the investigational Derma VaxTrademark injection system that delivers the vaccine into the skin. However, because the Derma VaxTrademark system has not been studied in humans, more research is needed to determine whether this new vaccine delivery method is safe and tolerable, particularly in terms of pain levels and skin reactions. 