[Quantitative characteristics of the survival phenomenon in experimental plague].

The method for the quantitative evaluation of the effect of the survival phenomenon is proposed, which makes it possible to carry out the rapid single-stage determination of the immunogenicity of Pasteurella pestis avirulent strains. The low specificity of the survival phenomenon in plague has been shown. The accumulation of immunogenic avirulent cells in the population of virulent P. pestis has been found to decrease their pathogenic action to a greater extent than the accumulation of nonimmunogenic avirulent cells.