Aims C. McGuinness

Hyperimmune whooping cough serum

Summary 1. Hyperimmune whooping cough serum obtained from donors immunized with phase I pertussis vaccine has been employed in passive immunization of 308 infants and children subsequent to exposure to whooping cough and in the treatment of 442 patients with whooping cough following the onset of paroxysms. 2. The results obtained closely parallel those reported earlier in the studies which indicated that the serum was of considerable value in the prevention and treatment of the disease. 3. The possible use of toxoid and/or purified agglutinogen for the development of hyperimmune serum, either one alone or in combination with vaccine, is in the process of investigation.

Studies with H. Pertussis

Summary Antitoxin for the two known toxins of H. pertussis is not found in human convalescent or hyperimmune human serum. Agglutinins or antibacterial antibodies are found in high titer in the hyperimmune serum of known high clinical potency. Agglutination is recommended as a means of assay of such sera and should be used routinely as a laboratory control test in the production of such sera for clinical use. A procedure for immunization of adult donors is discussed, and the technique for use of agglutination in such assays is presented in detail. Titers of the sera of a group of human donors during the course of immunization are recorded. Most striking is the variation that occurs in different donors in response to immunization and also in any given donor from time to time. This makes it imperative to follow immunization by laboratory assays of the sera and to use the results as a guide in the selection of donors.

Studies with hemophilus pertussis

Summary 1. Cross agglutination between B. parapertussis and H. pertussis inphase I has been shown by means of absorptive tests to be due to a common minor antigen. 2. The findings of Miller have been confirmed with respect to a generalwide incidence of parapertussis agglutinins among the general population. By means of agglutinin absorption, it has been shown that these agglutinins for B. parapertussis are specific in large measure, presumably as a result of specific infection by B. parapertussis , and are not the result of the common minor antigen which exists in both B. parapertussis and H. pertussis . Incidence of agglutinins for B. parapertussis in both children and inadults in two institutions, has been found to be lower than in the general population. In the general population, the incidence found has increased with age. 3. As a result of intensive immunization of either man or animals, the agglutinative titer versus the heterologous species is increased through the agency of the common minor antigen, but it is not known whether such agglutinins are effective in clinical cross protection against either disease. Skin testing for susceptibility to whooping cough with purified agglutinogen also stimulates production of these same agglutinins as well as those versus the major phase I antigen. 4. The use of purified agglutinogen as an intradermal reagent forstimulation of immunity, as well as in skin testing for susceptibility to whooping cough, is suggested. 5. The results of the present study suggest that only the relatively serious cases of parapertussis are diagnosed clinically and that these are similar to mild cases of whooping cough; the nature of the typical disease of parapertussis apparently is not recognized clinically in relation to the specific etiologic agent.