Immunity to diphtheria in the 4-70 year age group in Italy.
Diphtheria antibody level in serum samples obtained from 270 subjects aged 4-70 was measured by in vitro seroneutralization test on Vero cells. Of the studied population, 27.8% had an antibody titre below the protective level (< 0.01 IU/ml). The prevalence of susceptible subjects showed a significant age-related increase (p < 0.01), with the highest value (53.8%) in the 31-40 age group. Mean antibody titre was maximum in individuals aged 13-14, then decreased reaching the minimum level in the 41-50 age group. These data suggest that in individuals aged 30-50, diphtheria immunity is not satisfactory, both for prevalence of immune subjects and for antibody levels. Therefore, a revaccination of adults with reduced doses of diphtheria toxoid may be advisable.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000276:immunology*; D000907:Antibodies, Bacterial / Q000096:biosynthesis / Q000097:blood; D002648:Child; D002675:Child, Preschool; D004165:Diphtheria / Q000276:immunology* / Q000503:physiopathology; D004198:Disease Susceptibility / Q000276:immunology; D005260:Female; D006801:Humans; D007117:Immunization, Secondary; D007558:Italy; D008297:Male; D008875:Middle Aged; D009500:Neutralization Tests
D000907:Antibodies, Bacterial