CD4 and infection: Consistent with the observation at primary infection (Fig. 4), rA2-19F reinfection increased the frequency of IL4 expressing CD4+ T cells (15.54 ± 1.70 vs. 8.33 ± 0.82 %) and decreased the frequency of IFNγ expressing CD4+ T cells (31.46 ± 2.41 vs 48.08 ± 3.24 %).