You said that the secondary response is quicker because clonal selection and clonal expansion are skipped. But how is clonal expansion skipped if plasma cells still need to be produced in order to produce antibodies?
Clonal expansion are performed by undifferentiated B-cells. B-cells, once enough of them, differentiate into plasma and memory cells. When we have memory cells we already have the correct receptor protein for the pathogeic antigen so that all is left to do is for the memory cells to reproduce by mitosis into more memory cells but plasma cells as well. So yes, we do need to produce the plasma cells but these WILL be the correct cells to combact the infection and produce the antibodies straight away. I know it's a bit late but I hope it is useful.