Passive immunity is achieved from injection of: A. Antibodies B. Vaccines C. Antigens D. Histamines
Option A. Passive immunity is the transfer of active humoral immunity of ready-made antibodies (exogenous). Passive immunity can occur naturally, when maternal antibodies are transferred to the fetus through the placenta, and it can also be induced artificially when high levels of antibodies specific to a pathogen or toxin are transferred to non-immune persons through blood products that contain antibodies.
