Adjuvant effect of Bordetella pertussis vaccine to sheep erythrocytes in mice: enhancement of cell-mediated immunity by subcutaneous administration of adjuvant and antigen

The subcutaneous route (s.c.) was used to study the adjuvant effect of Bordetella pertussis vaccine (PV) on cell-mediated immunity to sheep erythorcytes (SRBC). The immune response was measured by a sensitive assay procedure in which the antigen is injected intracutaneously into the mouse ear and the inflammatory swelling is measured with calipers. PV significantly enhanced cell-mediated immunity to SRBC, and the enhancement persisted for at least 3 weeks. PV administered up to 6 days before SRBC also significantly enhanced the response; PV injected 1 or more days after SRBC was not effective. In addition, it was found that PV per se released into the suspension medium a cell-free component(s) (pertussis supernatant) that contributed significantly to adjuvanticity. The adjuvanticity of both PV and PS was completely eliminated by heat.