A study of immunization against diphtheria, tetanus, and pertussis by means of two injections of a mixture of aluminum hydroxide adsorbed diphtheria and tetanus toxoids containing H. pertussis vaccine was reported by Miller et al1 in 1944. Two injections of 1.0 cc. each of this triple adsorbed mixture* were shown to lead to the production of unusually high levels of tetanus antitoxin and to uniform Schick negativity. On the other hand, the protection obtained against pertussis as gauged by estimations of serum agglutinins and by the results of clinical exposures was not entirely satisfactory. Two cases of pertussis following indoor exposure occurred in the group. It was therefore recommended that the total dose of 40 billion H. pertussis, contained in the 2.0 cc. of triple mixture injected, be augmented. This has been done, and in a second group of infants and children the original schedule of two injections of mixed adsorbed toxoids with vaccine, injected at a 12 week interval, was modified by an additional injection of a Phase I H. pertussis vaccine in saline* given midway between the above two injections (6 weeks after the first injection). Varying doses of vaccine were used for this additional injection—20 or 30 billion cells in the form of 1.0 or 1.5 cc. of a 20 billion per cc. saline suspension, and 40 or 60 billion cells in the form of a 1.0 or 1.5 cc. of a 40 billion per cc. saline suspension.In the original study, herein referred to as Group
展开▼
