Which type of immunity is characterized by the transfer of antibodies from one individual to another?

• A. Active immunity
• B. Natural immunity
• C. Passive immunity
• D. Artificial immunity

Answer: (C)

The correct answer is passive immunity, which is characterized by the transfer of antibodies from one individual to another, providing immediate, though temporary, protection against pathogens. This can occur naturally, such as when a mother transfers antibodies to her infant through breast milk or across the placenta during pregnancy. It can also occur artificially, through medical procedures like receiving immunoglobulin treatments or monoclonal antibodies.

In contrast, active immunity comes from the body's own immune response to exposure to pathogens or vaccination, resulting in the production of antibodies and memory cells that provide long-lasting protection. Natural immunity refers specifically to immunity gained from natural infection, while artificial immunity relates to immunity obtained through medical interventions like vaccinations. Understanding these distinctions helps clarify how different forms of immunity operate in the body.