What is meant by passive immunity?

What is meant by passive immunity?

• A. Long-lasting immunity gained through vaccines
• B. The transfer of antibodies from one individual to another
• C. The process of developing immunity through infection
• D. The response of the immune system to foreign invaders

Answer: (B)

Passive immunity refers specifically to the transfer of antibodies from one individual to another, which is critical in providing immediate protection against infections. This type of immunity is typically short-lived because it does not involve the recipient's immune system actively producing antibodies; instead, they receive them directly. A common example of passive immunity is the transfer of antibodies from a mother to her infant through breast milk or across the placenta during pregnancy. This immediate boost in antibody levels helps protect the infant during the early stages of life when their own immune system is not yet fully developed.

In contrast, the process of developing immunity through vaccines or infections refers to active immunity, which is not the case here. Vaccines stimulate the immune system to produce its own antibodies, while natural infection leads to an immune response that creates memory cells, resulting in long-lasting immunity.