What is the term for receiving antibodies from another person or animal?

The correct answer is passive immunity, which refers to the process of acquiring antibodies that are produced by another individual or organism. In this case, the recipient's immune system does not have to generate its own response to an antigen, as they are receiving pre-formed antibodies. This can occur naturally, such as when a mother passes antibodies to her infant through breast milk or the placenta, or it can happen artificially, for example through antibody-containing blood products or vaccinations that include immunoglobulins.

Understanding this concept is crucial because passive immunity provides immediate protection, but it is temporary because the antibodies will eventually degrade and the recipient's immune system will not retain the ability to produce those antibodies independently. This contrasts with active immunity, where the body produces its own antibodies in response to an infection or a vaccination, which lasts longer and generally provides more enduring protection.