A Level Biology Practice Exam 2026 – All-in-One Study Guide to Excel in Your A Levels!

Artificial passive immunity is defined as immunity gained through the administration of antibodies that have been produced in another organism. This often involves administering immunoglobulins that are harvested from an animal or human who has been exposed to a particular pathogen. This type of immunity provides immediate protection against specific pathogens without requiring the recipient’s immune system to produce its own antibodies.

This contrasts with other forms of immunity: natural active immunity involves the body combating an infection and thus creating its own antibodies, while artificial active immunity is achieved through vaccination, which stimulates the immune system to generate a response. Immunity acquired through environmental exposures typically refers to natural methods of gaining immunity, such as through infections or environmental elements, which is not relevant to the concept of artificial passive immunity. Therefore, the best definition that captures the essence of artificial passive immunity is indeed the one describing the direct administration of antibodies from another animal.