Virus titers in the indicated tissue harvested from mice 3 dpi with APMV serotypes 1 to 9, expressed as mean fluorescent foci/gram of tissue.

All the values are the mean of 3 mice per group.*Titers were determined by serial dilution of clarified tissue homogenates from the experiment in Table 1 onto DF1 cells, which were overlaid with methylcellulose and immunostained 4 days later with N protein-specific antisera to detect viral foci.- = no virus was isolated.