DNA vaccine against a pathogen affecting farmanimals, in particular bovines or porcines, comprisinga plasmid containing a nucleotide sequence encoding animmunogen of a pathogen of the animal speciesconsidered, under conditions allowing the in vivoexpression of this sequence, and a cationic lipidcontaining a quaternary ammonium salt, of formula(see above formula)in which R1 is a saturated or unsaturated linearaliphatic radical having 12 to 18 carbon atoms, R2 isanother aliphatic radical containing 2 or 3 carbonatoms, and X a hydroxyl or amine group, this lipidbeing preferably DMRIE.
