Antigen A Antigen A Antigen B Anti-A Anti-B Secondary anti-A respons E Primary Primary antI-A anti-B response response 2 4 8 0 12 Weeks Figure 1-4 Specificity, memory, and self limitation of Immune responses. Antigens a and B induce the production of different antibodies Is ficityl. The secondary response to antigen A is more rapid and larger than the primary response(memory). Antibody levels decline with time after each immunization iself limitation