A histopathological slices in rat  immunized with WKL Ags. at 28 day post immunization. (A) Liver  showed focal MNCs infiltration in liver tissue with obvious binucleated hepatocyte. (B) Liver showed edema in hepatic tissue with anisonucleosis. (C) Spleen showed reactive lymphoid hyperplasia with slight red pulp congestion. (D) Spleen showed obvious paracortical lymphoid hyperplasia.