Immune System Practice Test 2026 – Your All-in-One Guide to Mastering Immunology!

Vaccines trigger the body's adaptive immune system to respond to a safe form of the pathogen, which leads to the production of memory cells. Because the immune system itself is actively responding and generating these memory B and T cells, the resulting immunity is active immunity. This type of immunity is long-lasting because the memory cells remain in the body and enable a faster, stronger response if the real pathogen is encountered later.

Passive immunity would involve receiving antibodies from another source, which doesn’t involve the body making its own memory cells and is usually temporary. Innate immunity is the non-specific first line of defense that doesn’t create memory. Humoral immunity refers to antibody-mediated responses, which are part of the active adaptive response, but the question’s key point is that the memory cells indicate active immunity rather than a passive or non-specific process.