Time Relationships Between Injection of Antigen and Adjuvant I. Adjuvancy of Bordetella pertussis Given at Various Times Before the Primary Antigenic Stimulus.

The adjuvant activity of Bordetella pertussis was investigated, both at the cellular and humoral levels, when the bacterial adjuvant was administered at various times before the primary antigenic stimulus of both 8 x 10(6) and 4 x 10(8) sheep erythrocytes. In all experiments, both adjuvant and erythrocyte antigen were given intraperitoneally. Adjuvant activity was measured on the basis of the primary immune response and on the degree of priming for the secondary immune reaction. A maximal effect on the primary immune response was found in mice which had received B. pertussis vaccine simultaneously with the erythrocyte antigen. A significant degree of adjuvancy was also demonstrable when B. pertussis vaccine was administered within a period of 48 hr before antigen. Adjuvant effectiveness was less as the time interval between the injection of antigen and adjuvant increased. The process of priming for the secondary response, however, was found to be equally affected when the adjuvant was given either simultaneously with the antigen or 12, 24, and 48 hr before sheep erythrocytes. On the basis of these and previous findings, it is suggested that adjuvancy of B. pertussis is caused chiefly by additional recruitment of responding cells. It is also suggested that memory-cell production may develop concurrently with, but independently of, the cellular proliferative events which lead to antibody formation during the primary immune response.