[The effect of the initial level of immunity on the efficacy of antidiphtheria inoculations in children and adults]. / Vliianie iskhodnogo urovnia immuniteta na éffektivnost' protivodifteriinykh privivok u detei i vzroslykh.

Based on results of examination in the passive hemagglutination test of 1440 subjects at different ages, several distinguishing features were revealed of formation of artificial active antidiphtheria immunity depending on the basic level of immunity. Single revaccination of those subjects presenting with the basic immunity of less than 0.03 IU/ml provides defence against diphtheria in only 33.3 percent of adults and 50 percent of children, in those subjects presenting with immunity between 0.03 to 0.99 IU/ml it is highly effective, in the immunity 1 IU/ml and beyond the effect of further immunization is very low since 25 to 33.3 percent of subjects demonstrate enhancement of immunity, whereas 16.7 to 25 percent show lowering of it. The analysis of the immunological structure of the population shows that 45 to 60 percent of adults in different age groups need to be exposed to single revaccination, 14 to 37 present will find it insufficient, 3 to 36 percent redundant. We suggest that revaccination against diphtheria be conducted under control of the level of antitoxic immunity.

[The results of multiyear observations on the duration of the maintenance of immunity in those vaccinated and revaccinated against and recovered from measles]. / Rezul'taty mnogoletnikh nabliudenii za dlitel'nost'iu sokhraneniia immuniteta u vaktsinirovannykh, revaktsinirovannykh i perebolevshikh kor'iu.

The results of 5-year observations on the duration of immunity to measles virus in persons vaccinated and revaccinated against measles, as well as in persons having had this infection, are presented. The intensity of immunity was determined in the same persons with the use of the passive hemagglutination test. The study revealed differences in the formation, intensity and duration of postvaccinal immunity. A significant decrease in the concentration of antibodies over the period of 5 years was established in 50.0-52.3% of vaccines. Revaccination with live measles vaccine is an effective measure for enhancing immunity to measles virus in persons with initial antibody titers less than 1:10-1:20, but revaccination made in a single injection is not sufficient for the stable maintenance of measles morbidity at the sporadic level. Postinfectious immunity is characterized by stability and has no tendency towards decrease. Persons having had measles have no need in additional measures irrespective of the time elapsed after the disease.

[Epidemiological and immunological features of tetanus under conditions of long-term planned vaccine prophylaxis]. / Epidemiologicheskie i immunologicheskie osobennosti stolbianka v usloviiakh mnogoletnei planovoi vaktsinoprofilaktiki.

The introduction of mass immunization against tetanus has resulted in the decrease of morbidity rate (5.2 times), the leveling of morbidity rate among the urban and rural population and among males and females, though no essential effect on the seasonal distribution of tetanus morbidity has been observed. Persons over 50 years of age (housewives and pensioners) have become the main groups of risk at the post-immunization period. Mass immunization against tetanus over a period of many years has ensured the existence of a sufficient immune stratum (89.9 +/- 3.0% to 100 +/- 3.0%) and a sufficient level of antitoxic immunity (means geom equal to 6.72-9.6 I.U./ml) among children. Among adults, the proportion of persons protected from tetanus decreases in older age groups from 82.1 +/- 1.3% in persons aged 31-40 years to 22.1 +/- 2.0% in persons over 60 years. The observed differences between the coverage of the population with immunization and the proportion of persons having protective titers of tetanus antibodies require constant control of the intensity of immunity and its correction with regard to its initial level, especially in persons of older age groups.

[Duration of the preservation of postvaccinal immunity against measles and the results of a repeat immunization of children with various initial antibody levels]. / Dlitel'nost' sokhraneniia postvaktsinal'nogo immuniteta protiv kory i rezul'taty povtornoi immunizatsii detei s razlichnym iskhodnym soderzhaniem antitel.

The study of the blood sera of vaccinated children carried out by means of the indirect hemagglutination test with the use of dried erythrocytic diagnostic reagents prepared at the Pasteur Institute of Experimental Medicine, revealed that in groups free from measles infection for a long time immunity in children grew lower as the time elapsed since the date of vaccination increased. In 9-12 years antibody titers in the vaccines decreased, the percentage of children with protective titers dropping from 83.5 to 36.3. The revaccination of seronegative children ensured a significant increase in antibody titers in 51.6% of such children with the preservation of protective titers for 1 year (the term of observation). The repeated immunization of seropositive children with initial titers of 1:10 to 1:20 significantly stimulated their increase, lasting for a very short time, in 84.2-89.2% of children. In children with an initial antibody titer of 1:40 short-term seroconversion was detected only in 20-7% of cases, and in those with an initial titer of 1:80 no cases of seroconversion were observed. The data thus obtained suggest that the revaccination of seronegative children should be recommended.

[Evaluation of the epidemiological effectiveness of hospitalization of patients with dysentery]. / K otsenke épidemiologichesko éffektivnosti gospitalizatsii bol'nykh dizenteriei

The authors present materials on the study of epidemiological efficacy of hospitalization of dysentery patients by statistical analysis (calculation of tendencies, rates of increase, etc.) of the indices of focal morbidity per 1000 contacts in the total number of foci characterized by various periods of isolation of the first patient. The work was carried out on materials of two towns considerably differing by the extent of organization of public services and amenities. The results obtained pointed to the relative epidemiological efficacy of hospitalization of dysentery patients particularly marked at the territory with less favourable living conditions.