Immunity against diphtheria and tetanus in various age groups after 40 years since implementation of the mass vaccination program

The aim of this study was to determine immunity against diphtheria and tetanus in various age groups and to compare it with the results of seroepidemiological studies conducted during previous 40 years. The level of diphtheria and tetanus antibody was determined by means of ELISA tests in 1534 sera obtained from persons aged 1-81 years. As elsewhere in Europe, the present study confirms the insufficiency of humoral immunity to diphtheria among Polish adults. Groups with the lowest levels of diphtheria antibody include persons aged 30-60 years (62% protected). Tetanus immunity was highest during the first three decades of life (above 90% protected), and then declined with increasing age. The comparison with results of several serologic surveys performed earlier showed gradually increasing immunity level against tetanus in all age groups.