During a secondary immune response, what accounts for the rapid rise in IgG levels?

The rapid rise in IgG levels during a secondary immune response is primarily due to the activation of memory B cells. These memory B cells are generated during the first exposure to an antigen and remain in the body long after the initial infection has resolved. When the same antigen is encountered again, these memory B cells can respond much more swiftly and effectively compared to naïve B cells.

Upon re-exposure to the antigen, memory B cells are activated and quickly differentiate into plasma cells that produce large amounts of IgG antibodies. This faster and more robust antibody response is a hallmark of the adaptive immune system, allowing the body to more effectively combat pathogens it has previously encountered. This process ensures that the immune system can respond to previously recognized antigens with a more potent and faster response, hence the significant increase in IgG levels.

Other options do not account for the specific characteristics of the secondary immune response. For instance, the presence of naive B cells does not significantly contribute to the rapid increase in IgG because these cells need time to mature and differentiate. Inhibition of IgM production is not the direct reason for the rise in IgG during a secondary response, as IgM is typically the first antibody produced in primary responses. Increased activation of T cells can