Summary of the pathological findings in challenged mice.

HN = hepatic necrosis; LD = Spleen lymphoid depletion; GCN = necrosis in germinal centers; HP = splenic hyperplasia; TN = tubular necrosis in kidney; BG = brain gliosis (*associated with viral antigen). Liver pathology was categorized from massive (+++) to moderate (+). Spleen pathology was ranked as severe (++++), intense (+++), moderate (++) or mild (+). Immunohistochemistry for viral N antigen detection; intense (+++), moderate (++), mild (+), weak (+/−).