University of Central Florida (UCF) PCB3233 Immunology Practice Exam 1

The primary immune response is the type of response that occurs upon first exposure to an antigen. This response is characterized by the activation of naive B and T lymphocytes, which have not previously encountered the antigen. During this initial encounter, the body takes time to recognize and process the antigen, leading to clonal expansion and differentiation of specific lymphocytes. It generally involves a lag phase where the immune system is learning how to respond effectively to the antigen.

As part of the primary immune response, the production of antibodies takes place, which includes the development of memory cells that will recognize the antigen in the future. This initial response can be slower, taking days to weeks to reach peak antibody production. Once the immune system has been primed by this first exposure, it will respond more swiftly and effectively during subsequent exposures to the same antigen, which is referred to as the secondary immune response.

Understanding the distinction between primary and secondary responses is crucial in immunology, as it highlights how the immune system adapts and improves its response through memory formation and enhanced capability upon subsequent encounters with the same pathogen.