Question

Why does your initial immune response to a bacterial infection/viral infection
take so long whereas a second exposure comes on very quickly?​

Answer 1

Answer:

Upon reinfection, the memory cells will immediately differentiate into plasma cells and CTLs without input from APCs or TH cells. In contrast, the adaptive immune response to the initial infection requires time for naïve B and T cells with the appropriate antigen specificities to be identified and activated.

well.. i dunno if it helped or not but still I tried... so sorry if it's not upto your standard.