What is the main role of memory cells?

• A. To phagocytize pathogens
• B. To carry out immediate immune responses
• C. To respond quickly to subsequent exposures of the same antigen
• D. To destroy infected host cells

Answer: (C)

The main role of memory cells is to respond quickly to subsequent exposures of the same antigen. After the initial immune response, some B and T cells become memory cells. These cells persist in the body long after the infection has been cleared and are specifically tailored to recognize and respond to the same pathogen if it re-enters the body. This allows the immune system to mount a robust and rapid response upon re-exposure, often preventing the pathogen from causing significant illness.

This enhanced response is crucial to the effectiveness of vaccinations, which aim to create memory cells without subjecting the individual to the disease itself. It is through this mechanism that memory cells provide long-lasting immunity and greater efficiency in combating infections in the future.