Studies on Diphtheria. III. The duration of immunity against diphtheria following vaccination as compared with that following clinical disease and carrier state

Abstract

SUMMARY A comparison is made between the antitoxin values found in the following groups of subjects: I. Subjects vaccinated two years and one year ago; II and III. Cases of clinical diphtheria 2 and 20 years ago; IV and V. Diphtheria carriers 2 and 20 years ago and VI. Non‐immunized control subjects. The results are condensed in table 6. The following facts should be stressed: The vaccinated subjects are by far better off, as judged from the antitoxin concentration, than the former clinical cases or carriers. The former carriers have on the whole somewhat better antitoxin values than the former clinical cases, when examined after 2 and 20 years but the difference is not very striking. The results do not give support to the view often held, namely, that the diphtheria cases represent a selection of poor reactors.