Live salmonella vaccine with a host species-adapted attenuation and an anti-epidemic potential

摘要

The vaccines are suitable for the active immunisation of humans and of productive livestock and are based on strains whose level of attenuation corresponds to a virulence reduction appropriate for the host species, whose stability (absence of back-mutation to the wild strain under non-selective conditions) derives in the case of one-marker strains from a non-detectable or /=10-8, and in the case of two-, three- or multi-marker strains from a /=10-7, reversion frequency per marker, and whose reduced excretion and diminished survival time in the outside world limits the possibility of the development of a chain of infection by the vaccine strain. The features of the invention comprise a single use or preferably a combination of virulence-reducing markers (aspartic acid auxotrophy, virulence-reducing metabolic drift markers) and, where appropriate, antiepidemic Hst, Rbt or Rtt markers. Also described are a process for the preparation of such vaccines and the use thereof.