THE EPIDEMIOLOGICAL EVALUATION OF A NON-CELLULAR PERTUSSIS ANTIGEN

A brief discussion of the background and current status of pertussis immunization has indicated the need for a more satisfactory immunizing agent. The clinical evaluation of a new non-cellular pertussis antigen is described. Statistical analysis of data from 197 children completely immunized with the non-cellular antigen, 207 completely immunized with whole organism vaccine and 238 non-immunized control children suggest the following conclusions: The epidemiological data relating to the non-cellular antigen indicates its ability to produce a satisfactory level of immunity to pertussis. The significantly higher agglutinin titers and better protection in humans suggest that there is a better response to time non-cellular antigen than to the control vaccine even though mouse protective activities were approximately equal. The non-cellular pertussis antigen caused a febrile reaction of shorter duration than the control vaccine and other less quantitative measures of toxicity indicated that the non-cellular antigen was less toxic than the control vaccine. The frequency of pertussis cases in both immunized groups was significantly lower than in the non-immunized control group. The groups employed in the study were significantly uniform and thus permitted a valid comparison of the results among the various groups.