Active immunity occurs when the body’s immune system is stimulated to produce an immune response. This can happen through natural exposure to pathogens or through vaccination. When an individual is exposed to a pathogen or receives a vaccine, the immune system recognizes specific antigens associated with the pathogen and mounts a response. If, by itself, the antigen does not stimulate the immune system, a second component that will active a response must accompany the antigen. Active adaptive immune responses are mediated by the production of antibodies and by the generation of cytotoxic T cells. The generation of memory cells may also occur, potentially providing long-lasting protection by enabling a quicker and more robust active immune response upon subsequent encounters with the same pathogen.
Passive immunity, on the other hand, involves the transfer of pre-formed antibodies or immune cells from an external source to an individual. This can occur naturally, such as the transfer of maternal antibodies to a newborn through breastfeeding, or artificially through the administration of antibodies (antibody therapy) or immune cells. Passive immunity provides immediate but temporary protection, as the recipient does not produce the antibodies themselves, and there is no formation of memory cells. The duration of protection is limited to the lifespan of the transferred antibodies or cells.
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Source: ChatGPT response prompted and edited by Joel Graff.
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