CD40LG and infection: However, infection with NDV AF2240 resulted in a greater decline in IgM+ cell number from an initial figure of 1.78 × 106 ± 36 cells to 1.24 × 106 ± 101 cells (Table 1) compared to NDV IBS002 for which the cell number of IgM+ cells reached 1.37 × 106 ± 115 cells at day four post infection (Table 1).