[The protective activity of individual proteins and immunogenic fractions isolated from Rickettsia prowazekii]

The immunogenic properties and protective activity of basic protein I and tris-soluble antigens isolated from R. prowazekii were analyzed in comparison with those of chemical typhus vaccine on the model of anti-infectious immunity in guinea pigs. The analysis revealed that purified protein I has protective activity for guinea pigs, which is less pronounced in protein I from strain E with weak pathogenicity than protein I from strains EVir and Breinl. The activity and immunogenic properties of tris-soluble antigens, especially antigen I, are comparable with those of chemical typhus vaccines in the parameters under study.