Antibody production in secondary immune response Can IgG antibodies be produced in the secondary immune response without the help of T cells? Is the affinity of antibody for antigens higher during secondary immune response?

1) The secondary response requires CD4+ T cells to activate memory B cells. That first paper actually gives some evidence that some of the rapidity could arise because T cells and memory B cells are in very close proximity to each other in germinal centers.

2) Yes. The affinity of antibodies increases during the _initial_ infection, both through isotype switching and affinity maturation, producing far superior antibodies. Upon reactivation, memory B cells can undergo further somatic hupermutation.