Fig. 7
From: A methodological approach for using high-level Petri Nets to model the immune system response
Typical immune system primary and secondary response. Different antigens (X and Y) induce the stimulation of B cells with different specificity, and thus entitle the production of different antibodies (a reflection of specificity). The secondary response to the antigen X is more rapid and stronger than the primary response (underlying memory importance) and is different from the primary response to the antigen Y (again reflecting specificity). Antibody levels decline with time after each immunization