The
adaptive immune system, also known as the
acquired immune system or, more rarely, as the
specific immune system, is a subsystem of the overall
immune system that is composed of highly specialized, systemic cells and processes that eliminate or prevent
pathogen growth. The adaptive immune system is one of the two main
immunity strategies found in
vertebrates (the other being the
innate immune system). Adaptive immunity creates
immunological memory after an initial response to a specific pathogen, and leads to an enhanced response to subsequent encounters with that pathogen. This process of acquired immunity is the basis of
vaccination. Like the innate system, the adaptive system includes both
humoral immunity components and
cell-mediated immunity components.