Final answer:
In the presence of an identical antigen for the second time, the body can swiftly produce a large number of antibodies due to the existence and rapid action of memory B cells which quickly differentiate into plasma cells and produce high levels of antibodies.
Step-by-step explanation:
The second time you are exposed to the identical antigen, you produce more antibodies more quickly because of the presence of memory B cells. Following the initial infection, plasma cells secrete antibodies, and some B cells differentiate into memory B cells. These memory B cells are programmed to respond rapidly upon subsequent exposures to the same pathogen. They immediately differentiate into plasma cells without the need for additional input from antigen-presenting cells (APCs) or helper T cells (TH cells), resulting in a swift and substantial production of antibodies. This secondary immune response is more efficient as it produces higher and more sustained levels of antibody with greater affinity to the pathogen, potentially halting the infection before symptoms can develop.