What is a "memory T cell"?

A memory T cell is a specialized type of T lymphocyte that develops after an initial immune response to an antigen. It retains information about the antigen and provides long-term immunity against future encounters with the same pathogen. Memory T cells are able to rapidly recognize and respond to the antigen, leading to a more efficient and effective immune response. They play a vital role in adaptive immunity, contributing to the body's ability to mount a quick and robust defense against recurring infections or reinfection with the same pathogen.