In immune responses, what is the role of memory cells?

• A. They enable a faster and stronger response upon re-exposure
• B. They suppress immune response
• C. They produce antibodies of identical affinity
• D. They cause allergies

Answer: (A)

Memory cells provide rapid and robust protection upon re-exposure to the same antigen. They are long-lived descendants of activated B and T cells that persist after the initial response. When the same pathogen is encountered again, these memory cells respond quickly and more strongly: memory B cells promptly become antibody-secreting plasma cells, often producing high-affinity, class-switched antibodies, while memory T cells rapidly expand to support helper or cytotoxic responses. This accelerated secondary response is what vaccines aim to establish. The other ideas don’t fit this role: immune suppression comes from regulatory mechanisms, memory cells don’t inherently produce identical-affinity antibodies (affinity can improve with maturation), and allergies involve IgE-mediated hypersensitivity, not the general function of memory cells.