[The results of an immunoepidemiological examination of foci of epidemic parotitis].

The immunoepidemiological survey of 54 foci of epidemic parotitis showed that the epidemiological effectiveness index at preschool institutions, equal to 2.7, was essentially higher than at schools (2.1). The significant difference (t = 3.35) in the epidemiological effectiveness indices was due to the presence of a large number of persons having had inapparent and faintly pronounced forms of epidemic parotitis among school children, as well as due to more close contacts of children with the foci of infection at preschool institutions. The study showed that among children immunized with some lots of parotitis vaccine elevated morbidity in epidemic parotitis was registered. In the foci of infection children, immunized in the presence of low initial titers of specific hemagglutinins in their sera, responded by a booster effect with different duration of stimulation of antibody formation. The hemagglutinin titer of 1:20 was shown to protect children from epidemic parotitis.