immunological memory

Immunological memory is the immune system's ability to remember and respond more quickly to a pathogen it has previously encountered. When the body fights an infection, it creates memory cells—special immune cells that recognize the specific pathogen. If the same pathogen invades again, these memory cells enable the immune system to respond rapidly and effectively, often preventing illness or reducing its severity. This process is the foundation of how vaccines provide lasting protection by training the immune system to recognize specific threats without causing illness.