What term describes the response that occurs upon subsequent exposure to the same antigen?

The term that describes the response occurring upon subsequent exposure to the same antigen is known as the anamnestic response. This immune response is characterized by its rapid and heightened reaction compared to the primary immune response, which occurs during the first exposure to an antigen.

During the primary immune response, the immune system takes time to recognize the antigen and produce specific antibodies, leading to a slower response. However, upon re-exposure to the same antigen, memory cells that were generated during the primary response are activated more quickly. This results in a stronger and faster production of antibodies, providing the body with improved protection against the reintroduced antigen.

This concept is particularly important in immunology and vaccination strategies, as it highlights the role of memory B and T cells in generating long-lasting immunity after an initial exposure.