CD8A and Zinc deficiency: From the results shown in Fig. 5A–C and a sum of 5 independent experiments in Fig. 5D, we observed the lowest level of IFN-γ expression for the HBsAg-specific CD4+ and CD8+ T cells in the pups from zinc deficiency group, whereas the percentage of IL-4 in CD4+ T cells was not changed compared with the control group.