Production and application of a live Salmonella gallinarum vaccine

The production and application of a freeze-dried Salmonella gallinarum vaccine are described in this report. The vaccine is stable when kept at 4 degrees C and a single injection elicits a good immunity for 2 months, though its effect gradually diminishes. Immunity is neither enhanced nor depressed by repeated injections of the live vaccine, and no interference effect was observed in experimentally infected chickens. Furazolidone therapy jeopardizes the immunogenicity of a live vaccine, but its effect can be countered by the administration of either an inactivated or a live vaccine when medication is commenced and this is followed by the application of live vaccine 6 days after cessation of medication.