I shall talk first about diphtheria, tetanus and whooping cough, and the use of single and then multiple antigens. Following this we will have a short period for discussion.
Diphtheria: Up to World War II it was generally assumed that most of the adult population of the United States was immune to diphtheria. Many studies since 1941 have shown this is no longer the case. Depending upon locality 25 to 50% of our adult population now is susceptible. Infants of susceptible mothers likewise are not immune, and there has been an increasing amount of diphtheria in infants under 6 months of age. This phenomenon, of course, is due to the steadily decreasing carrier rates. Immunity to diphtheria depends upon constant restimulation which now, in general, must be provided artificially. Immunity following active immunization cannot be counted on lasting more than 3 to 4 years.
Reactions to diphtheria toxoid have been one of the chief problems in diphtheria immunization, especially in older children and adults. Methods of purification developed by Pillemer and others in recent years have made available vastly superior toxoids which also contain considerably less alum than the pre-War products. One must remember, however, that some individuals are sensitive to toxoid itself, and such persons will react adversely to the material regardless of its freedom from impurities. Most infants and young children are not sensitive to diphtheria toxoid. Older children and adults should receive a Schick test and Schick test control prior to immunization in order to rule out those who definitely are sensitive to the material.
- Copyright © 1951 by the American Academy of Pediatrics