Describe the secondary (memory) response: characteristics, intensity, duration and cells.

A small percentage of the cells produced by B cell proliferation do not secrete antibodies but survive as memory B cells, long-lived cells with BCRs complementary to the specific antigen that triggered their production. In a primary immune response, relatively small amounts of antibodies are produced slowly and are of limited effectiveness. When an antigen is encountered a second time, the activation of memory cells in the secondary immune response ensures that the immune response is rapid and strong. Enhanced immune responses to subsequent exposures are called
memory responses.

Some activated T cells become memory T cells and can persist for months or even years in lymphoid tissues. Contact with an antigenic determinant matching its TCR prompts the memory T cell to immediately produce cytotoxic T cells. As with humoral immunity, a memory response is more rapid and more effective than a primary response.