Which type of immunity lasts long-term as a result of the body's own immune response to a pathogen?

Which type of immunity lasts long-term as a result of the body's own immune response to a pathogen?

• A. Active immunity
• B. Passive immunity
• C. Natural immunity
• D. Universal precautions

Answer: (A)

Active immunity lasts long-term because the body's adaptive immune system creates memory after exposure to a pathogen or a vaccine. When this happens, memory B cells and memory T cells are formed and persist, so a subsequent encounter with the same pathogen triggers a rapid and stronger response, often preventing illness or greatly reducing its severity for years or even a lifetime. This protection comes from the body's own response, unlike passive immunity, where antibodies are borrowed from another source and wane over time. Natural immunity is a broader term that can describe such active protection acquired through infection or vaccination, but the crucial point is that long-lasting protection is produced by the body's own immune response and memory formation.

Active immunity lasts long-term because the body's adaptive immune system creates memory after exposure to a pathogen or a vaccine. When this happens, memory B cells and memory T cells are formed and persist, so a subsequent encounter with the same pathogen triggers a rapid and stronger response, often preventing illness or greatly reducing its severity for years or even a lifetime. This protection comes from the body's own response, unlike passive immunity, where antibodies are borrowed from another source and wane over time. Natural immunity is a broader term that can describe such active protection acquired through infection or vaccination, but the crucial point is that long-lasting protection is produced by the body's own immune response and memory formation.