[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.