Disclosed are plasmids that contain and express in vivo in a feline host cell nucleic acid molecules. The plasmid can include nucleic molecule(s) having sequence(s) encoding infectious peritonitis virus M; feline immunodeficiency virus env, or gag, or pro, or gag and pro, or env and gag and pro; rabies G; or feline leukemia virus env and/or gag. Compositions containing such plasmids, methods of use employing such plasmids, and kits involving such plasmids, are also disclosed.