In recent years, the epidemic situation in diphtheria has deteriorated sharply. An essential point in assessing the dynamics of the epidemic process of diphtheria is the determination of the state of immunity of the population. Judging by the numerous publications [4-5], the number of immune persons and the level of antibodies in them in different years and in certain territories are different. Given that the highest incidence is currently observed among adults, we decided to study the state of protection not of the total population, but of adults. The intensity of immunity to diphtheria and tetanus in the adult population of Kazan was studied by us in 1992 against the background of epidemic well-being, at that time in Moscow, St. Petersburg, Moscow, Leningrad, Irkutsk regions, Primorsky Krai, there was a significant increase in the incidence of diphtheria.

Tension of antidi phtheria immunity among uninoculated persons in various indicatory groups of population of Tatarstan Republic in the presence of epidemic process intensification is studied. It is revealed that in 44,576,5% of uninoculated inhabitants in various indicatory groups and classes of population the titers were lower than protective. Taking into account a large percent of unprotected persons and absence of financial and material possibilities of determining the immunity level before inoculation the practice of performing thrice-repeated inoculation of adults older than 30 is justified.

Level of antidiphtherial immunity among indicatory groups of Tatarstan Republic is studied for improving vaccinal prevention and developing management decisions and recommendations. The increase of antitoxic immunity in groups aged 23 to 1617 and its decrease with age rise especially in persons aged 3637 and 4647 are noted. For revaccination of persons aged 2627 it is appropriate to perform single immunization, for persons aged 3637, 4647, 56 and older selective immunization is used taking into account the results of passive hemagglutination reaction

The intensity of immunity to diphtheria and the indicated groups of population in Tatarstan Republic is studied. The work organization described allows, furthermore, to perform a comparative analysis for population of various classes and to create the data base for the realization of similar work in perspective.