Which term describes immunity achieved without the host generating its own response, often by transfer of antibodies?

Which term describes immunity achieved without the host generating its own response, often by transfer of antibodies?

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

Answer: (A)

Immunity acquired without the host actively generating its own response is called passive immunity. In this form, antibodies are provided from another source and can act immediately to neutralize pathogens or toxins. Because the host’s immune system isn’t activated to produce its own antibodies or memory cells, the protection is temporary, waning as the transferred antibodies are cleared. Natural passive immunity occurs when maternal antibodies cross the placenta or are passed through breast milk. Artificial passive immunity uses antibody-rich preparations like immune globulins or antivenoms to offer rapid protection after exposure. This differs from active immunity, where exposure to an antigen prompts the host to mount a response and develop memory for longer-lasting protection. Adoptive immunity involves transferring immune cells rather than antibodies.

Immunity acquired without the host actively generating its own response is called passive immunity. In this form, antibodies are provided from another source and can act immediately to neutralize pathogens or toxins. Because the host’s immune system isn’t activated to produce its own antibodies or memory cells, the protection is temporary, waning as the transferred antibodies are cleared. Natural passive immunity occurs when maternal antibodies cross the placenta or are passed through breast milk. Artificial passive immunity uses antibody-rich preparations like immune globulins or antivenoms to offer rapid protection after exposure. This differs from active immunity, where exposure to an antigen prompts the host to mount a response and develop memory for longer-lasting protection. Adoptive immunity involves transferring immune cells rather than antibodies.