Immunity against diphtheria in the age group 15 to 25 years

Levels of diphtheria antitoxin in 254 serum samples were estimated in subjects in the age group 15 to 25 years with no previous history of immunisation against diphtheria using indirect haemagglutination test. All the individuals showed more than 0.03 IU/ml of diphtheria antitoxin level. This indicates that the age group studied was not susceptible to diphtheria. No significant relationship could be, however, ascertained between diphtheria antitoxin level and epidemiological factors like age, area (rural/urban), socioeconomic status, family size, education status and religion.