Improved DNA vaccine plasmids are disclosed that contain novel immunostimulatory RNA compositions. The improved plasmids eliminate all extraneous sequences, incorporate a novel antibiotic free short RNA based selectable marker, increase eukaryotic expression using a novel chimeric promoter, improve yield and stability during bacterial production, and improve immunostimulation. These vectors are utilised in immunisation to elicit improved immune responses or therapy to induce type 1 interferon production.