The present invention relates to a combination of compounds for introducing nucleic acids and/or protein into animal cells, tissue, organs or organisms in vitro, extracorporal, or in vivo. This combination comprises preparations suitable for administration to an animal or human for medical purposes, comprising as one component a bacterial vector genetically manipulated to contain nucleic acid sequences comprising a transgene, and a second component for the subsequent transcription, possibly translation of the transgene by controlled induction of bacterial vector as it is present within the animal or human.