adaptive immunity
(uh-DAP-tiv ih-MYOO-nih-tee)
A type of
          immunity that develops when a person’s immune system
          responds to a foreign substance or microorganism, such as
          after an infection or vaccination. Adaptive immunity
          involves specialized immune cells and antibodies that
          attack and destroy foreign invaders and are able to prevent
          disease in the future by remembering what those substances
          look like and mounting a new immune response. Adaptive
          immunity may last for a few weeks or months or for a long
          time, sometimes for a person’s entire
          life.