A novel approach to the development of needed vaccines uses DNA for immunization. DNA represents the genetic blueprint for life. When DNA is used for immunization, the DNA in plasmid form provides the code for the vaccinating protein. The actual production of the immunizing protein takes place in the DNA-inoculated host, initiating both humoral and cellular immunity. DNA vaccines are administered in saline using hypodermic needles or by propelling DNA-coated gold beads into skin using gene guns. Recent results obtained in animal models indicate that this new technology may revolutionize the vaccination of humans. Protective immunity has been achieved for such major killers as diarrhea-causing viruses, tuberculosis-inducing bacteria, and malaria-inducing parasites. These new DNA vaccines also hold promise for being safer, less expensive, and easier to produce and administer than conventional vaccines. This report is based on a colloquium of experts convened to consider this new and extremely promising technology.