What results from the transfer of antibodies from one individual to another?

The transfer of antibodies from one individual to another is referred to as passive immunity. This type of immunity occurs when antibodies produced by one organism are given to another, providing immediate but temporary protection against specific antigens. This mechanism is often seen in scenarios such as a mother transferring antibodies to her infant through breast milk or in medical treatments where patients receive antibody-rich serum to help combat infections or diseases.

Unlike active immunity, where the individual's own immune system produces antibodies in response to an infection or vaccination, passive immunity does not require the recipient's immune system to be activated. Instead, it relies on the direct provision of antibodies. Consequently, while passive immunity can confer immediate protection, it typically lasts for a shorter duration compared to the long-lasting effects of active immunity, where memory cells are formed.

Adaptive immunity can be slightly more complex as it encompasses both passive and active forms of immunity and involves specific immune responses tailored to particular pathogens. Conversely, innate immunity refers to the body's pre-existing defenses against pathogens, which do not involve antibodies. Understanding these distinctions helps clarify the nature of passive immunity as the correct answer in this context.