Which type of immunity is initiated when the body produces its own antibodies?

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

Answer: (B)

Active immunity refers to the type of immunity that occurs when the body produces its own antibodies in response to an antigen. This process typically happens after exposure to a pathogens, such as through an infection, or through vaccination. When a person is vaccinated, for example, it introduces a harmless component of the pathogen to the body, prompting the immune system to recognize it as foreign and produce specific antibodies against it. This leads to a long-lasting immunity because the body remembers how to fight off that particular pathogen in the future.

In contrast, passive immunity is when antibodies are transferred from one individual to another, providing immediate but temporary protection without the recipient's immune system actively producing them. Natural immunity is often considered synonymous with active immunity but may emphasize the body's ability to gain immunity through natural exposure rather than artificial means, like vaccination. Adaptive immunity is a broader term that encompasses the specific immune responses including both active and passive immunity, but it doesn’t specifically highlight the production of antibodies by the individual's own immune system as a hallmark.

Therefore, the definition of active immunity distinctly supports the idea of the body’s engagement in antibody production, making it the correct choice in this context.