DNA vaccines offer many potential benefits when compared to earlier generation technologies. For example, a DNA vaccine does not have the safety issues presented by a live attenuated virus to an immunocompromised individual. In addition, DNA vaccines benefit from more economical manufacturing processes and can typically be stored without refrigeration. This feature makes a DNA vaccine easier and less expensive to handle and store; a major benefit for developing countries with limited resources.

However, there are significant challenges faced in the development of DNA vaccines. In particular, efficacy for a DNA vaccine is dependent on the ability to achieve intracellular delivery of the DNA plasmid payload. When injected by conventional syringe either subcutaneously or intramuscular, tissue cell membranes are a significant barrier to uptake of the DNA material. The implementation of drug-delivery technologies to DNA vaccine development is showing significant benefits to efficacy. Electroporation is a technique shown to increase intracellular delivery by the transient increase in cell membrane permeability by producing a controlled electric field during injection of the vaccine. Upon termination of electroporation, cell membrane integrity and function is rapidly returned to normal. Electroporation has potential for DNA delivery to skeletal muscle, skin, lung, and other tissues. Another prominent technique is the “gene gun,” which uses compressed helium to drive plasmid DNA that has been adsorbed onto gold or tungsten microparticles into target cells. Both techniques have demonstrated significant increases in immune response. Other drug-delivery technologies being investigated include nasal, inhalation, and oral routes of administration. Formulation approaches to increase immune response include cationic liposomal and biodegradable microsphere technologies.

Development of DNA vaccines continues to show promise. A veterinary DNA vaccine for horses has been approved and there are currently more than 15 human diseases being investigating using the technology.