Serological Immunity to Diphtheria in Sweden in 1978 and 1984

Abstract

Antibody levels in relation to diphtheria toxin were studied in 2409 serum specimens collected from different age-groups in Sweden in 1977–78 and 1983–84. Among children and young adults <20 years of age, 46% showed antibody levels considered to be protective (≥0.1 IU/ml). The corresponding percentage among adults was 21%. In the child population, 35% showed a relative degree of protection (<0.1-≥0.01 IU/ml), while 19% lacked immunity (<0.01 IU/ml). After 40 years of age, only 15% showed protective levels. No difference between males and females was seen in the younger population, while women had a lower prevalence of immunity than men among the adult population. Thus, more than 70% of the adult women lacked immunity, while the figure for the men was 50%.