\-**__________ immunity:** Transfer of ***antibodies*** from one person to another (wanes over time) such as:
-A mother to fetus or baby because antibodies pass in the placenta and breast milk.
-Intravenous for autoimmune or cancer patients
-5 major classes: IgA, IgD, IgE, IgG, IgM
-A varying amino acid sequence to give us millions of unique immunoglobulins each capable of combining with a specific antigen.