[Comparative immunomorphological study of the immunogenic activity of dysentery vaccines produced by different methods]. / Sravnitel'noe immunomorfologicheskoe izuchenie immunogennoi aktivnosti dizenteriinykh vaktsin razlichnogo sposoba izgotovleniia.

The morphological study of the ophthalmic mucosa of guinea pigs immunized locally with different dysentery vaccines has demonstrated the advantages of live dysentery vaccine prepared from Shigella sonnei 6S over heated vaccine and Shigella antigen extracts. The protective properties of dysentery vaccines, their capacity for protecting the mucous membrane from the penetration and intracellular multiplication of shigellae correlates with the degree of the manifestation of vaccine-induced plasmatocellular reaction in the epithelial and subepithelial zones. The importance of the virulence of the strains used for the preparation of vaccines, as well as the method of their preparation, for the immunogenic potency of vaccines is shown.

[Enteric dysentery vaccines and their effectiveness in a rabbit intestinal loop model. I. The residual virulence of attenuated vaccinal strains of Shigella administered into the intestinal loops]. / Izuchenie énteral'nykh dizenteriinykh vaktsin i ikh éffektivnosti na modeli kishechnykh petel' krolika. Soobshchenie I. Ostatochnaia virulentnost' attenuirovannykh vaktsinnykh shtammov shigell pri vvedenii v kishechnye petli.

Virulent Sh. flexneri strain 2a, Sh. sonnei strain, attenuated Sh. flexneri vaccine strain 2a 516M, and Sh. sonnei vaccine strain 6S (isolated by Yu. A. Belaya), as well as streptomycin-dependent Sh. flexneri strain 2a 1605/3 (isolated by V. V. Sergeev) were introduced into the ligated loops of the rabbit ileum. The use of light and immunofluorescent microscopy, the measurement of the volume of the fluid in the intestinal loops and the quantitative inoculation of their contents resulted in revealing the differences in the properties of the virulent and vaccine strains. The vaccine strains, in contrast to the virulent strains, did not proliferate in the lumen and did not cause the accumulation of fluid in the intestinal loops. They retained sharply limited, especially in the streptomycin-dependent bacteria, ability to penetrate into enterocytes and, via their cytoplasm, into the basement membrane, but lost their ability to proliferate in the cytoplasm of enterocytes (and probably even deteriorated there) and to cause plurulent ulcerous inflammation. This indicates that vaccine strains have insignificant residual virulence and suggests that the intestinal loop models, together with other models, may be used for testing the safety of vaccines prepared from Shigella strains.