[The use of the cluster selection method for assessing the status of immunity to controlled infections (measles, diphtheria and tetanus)].

The use of the method of cluster selection in mass serological examination makes it possible to obtain statistically significant results with very low expenditures. The coincidence of the results on the number of seronegative children, obtained by the method of cluster selection, with the results of mass serological examination of all children aged 6-7 years in the district (children found to be seronegative to measles constituted 5.5% and 5.0% respectively) is indicative of the statistical significance of the method used in this investigation. The results obtained by the method of cluster selection indicate that the level of protection among the children of the district was high both with respect to measles (94.5 +/- 1.8%) and tetanus (96.5 +/- 1.7%); with respect to diphtheria, the immune stratum was found to be less (91.1 +/- 2.3%). These data may be helpful in working out scientifically substantiated administrative decisions contributing to an increase in the effectiveness of planned mass immunization.