Final answer:
Once pathogen clearance begins post-primary response, a shift occurs towards the development of immunological memory, leading to the formation of memory B cells. These cells allow for a stronger and faster secondary immune response upon re-exposure to the same pathogen, characterized by higher antibody production and more effective antibodies.
Step-by-step explanation:
Shift in Immune Response Following Pathogen Clearance
Once the primary response begins to slow due to a pathogen being cleared, there is a shift from an active immune response to the development of immunological memory.
During the primary response, certain B cells differentiate into memory B cells, which are then ready to mount a quicker and more effective response upon re-exposure to the same pathogen.
This secondary immune response generates memory cells that differentiate into antibody-secreting plasma cells, producing a greater amount of antibody for a longer period of time.
Furthermore, this enhanced secondary response is characterized by a shorter lag period, higher production of IgG, and antibodies that have a higher affinity to targeted epitopes.
Additionally, plasma cells produced during secondary responses have a greater lifespan than those from the primary response, maintaining elevated levels of specific antibodies for a longer duration.
This mechanism is essential in preventing reinfections by the same pathogen.