Which type of immunity is transferred passively from a mother to her developing fetus across the placenta or through breast milk containing maternal antibodies?

💡 Solution & Explanation

Natural passive immunity occurs when preformed antibodies are transferred naturally from mother to offspring, such as IgG crossing the placenta and IgA passing through colostrum, conferring immediate temporary protection. Natural active immunity develops when an individual contracts an infection and mounts an endogenous immune response. Artificial active immunity is achieved through vaccination with attenuated antigens. Artificial passive immunity involves injecting exogenous antiserum containing ready-made antibodies.