Organisms are not born with adaptive immunity and it is not “hard wired” in their genes like innate immunity. It is acquired during their lifetime as a result of exposure to specific antigens, be that through natural means such as infection or by vaccination. Consequently, it is also known as acquired immunity. An adaptive immune response is much slower than an innate response, taking days or even weeks to develop on first encounter (the primary immune response), but is specific to the antigen(s) present and can retain a long term “memory” to enable a faster response if it is encountered again in the future. Adaptive immunity does it necessarily last throughout an organism’s entire lifespan, especially if it is not regularly re-exposed, although it can.