Which of the following best describes passive immunity?

• A. Provided when antibodies are given to a person rather than produced by their own immune system
• B. It develops after exposure to a disease organism triggers production of antibodies
• C. It results from vaccination and produces long-term immunity
• D. It cannot occur in adults

Answer: (A)

Passive immunity is when antibodies are transferred to you from someone or something else, rather than you producing them yourself. This gives immediate protection, but it’s temporary because the antibodies are eventually cleared and no lasting immune memory is formed. It can occur naturally (such as maternal antibodies passed to a fetus or through breast milk) or artificially (through injections of immune globulin). This differs from active immunity, which happens when your body encounters a pathogen or a vaccine and actively makes its own antibodies, creating long-term protection. The description that matches passive immunity is the one stating antibodies are given to a person rather than produced by their own immune system.