What term describes immunity acquired through production of antibodies within the organism in response to antigens?

• A. Passive Immunity
• B. Active Immunity
• C. Morbidity
• D. Mortality

Answer: (B)

Active immunity is when the body learns to defend itself by producing its own antibodies in response to an antigen. When the immune system encounters an invader or a vaccine, B cells become plasma cells and manufacture specific antibodies, and memory cells remain to provide long-lasting protection. This means the protection is typically durable because the body has learned how to recognize and fight that antigen again. In contrast, passive immunity relies on antibodies acquired from another person or source and offers immediate but temporary protection, since the antibodies eventually disappear. Morbidity and mortality describe disease occurrence and deaths, not how immunity is acquired.