What is the method by which artificially acquired passive immunity is gained?

Artificially acquired passive immunity is achieved through the direct introduction of antibodies into the body, providing immediate protection against specific pathogens without requiring the immune system to produce the antibodies itself. This is accomplished by inoculation with immune serum, which contains ready-made antibodies that can neutralize or mark pathogens for destruction by the immune system.

The other options, while related to immunity, describe different methods. Vaccination with live attenuated pathogens stimulates the immune system to develop its own long-term immunity through exposure to weakened forms of the pathogen, which is a process of active immunity. Exposure to infectious agents can lead to natural active immunity, where the body responds to an actual infection by producing antibodies. Transfusion of blood from a convalescent person also involves passive immunity but does not specifically refer to the artificial introduction of antibodies from a serum that is specifically prepared for this purpose. Therefore, inoculation with immune serum is the most precise method representative of artificially acquired passive immunity.