Immunological Memory
Antibody Titer: The amount of antibody in the serum.
Pattern of Antibody Levels During Infection
Primary Response:
After initial exposure to antigen, no antibodies are found in serum for several days.
A gradual increase in titer, first of IgM and then of IgG is observed.
Most B cells become plasma cells, but some B cells become long living memory cells .
Gradual decline of antibodies follows.
Secondary Response:
Subsequent exposure to the same antigen displays a faster and more intense antibody response.
Increased antibody response is due to the existence of memory cells, which rapidly produce plasma cells upon antigen stimulation.