• The effectiveness of immunization to diphtheria, tetanus, and pertussis was studied in a group of infants between 2 and 6 months of age. Two dosage levels were tried. The titers for diphtheria and tetanus antitoxin and for pertussis agglutinin were determined a month after the injections and again at the end of a year. With but one exception, the larger dose resulted in the higher titer. The feasibility and advisability of immunizing infants starting between the second and sixth months was demonstrated. The alum-adsorbed toxoids gave better results than the fluid preparations. Assays in the guinea pig afford some indication of the effectiveness of toxoids in man. Since the size of the dose was found to be so important, the search for more accurate methods of assay is justified.
Greenberg L, Benoit R. CONTROL OF POTENCY AND THE DOSAGE OF DIPHTHERIA AND TETANUS TOXOIDS. JAMA. 1956;160(2):108-113. doi:10.1001/jama.1956.02960370018005