Which term refers to immunity that develops over the lifetime and provides long-term protection against specific invaders?

• A. Innate Immunity
• B. Passive Immunity
• C. Adaptive Immunity
• D. Active Immunity

Answer: (C)

Adaptive immunity is the part of the immune system that learns to recognize specific pathogens and remembers them for the future. After the body is exposed to a particular invader or receives a vaccine, B and T lymphocytes tailor a targeted response and create memory cells. These memory cells persist for long periods, so subsequent exposures trigger a faster, stronger reaction and long-lasting protection against that specific invader. This capacity to develop with time and to protect selectively over years or a lifetime is what sets adaptive immunity apart. Innate immunity is immediate and non-specific, not geared to lasting, specific protection. Passive immunity involves receiving antibodies from another source and is temporary. Active immunity describes the host actively mounting a response to an antigen (a process that underpins adaptive immunity), but the lasting, specific protection that develops over a lifetime is the hallmark of adaptive immunity.