CD4 and infection: We chose to include animals from these previous studies to bolster the total sample size and introduce the following perturbations to the measured responses: 1) maternal plasma VL was higher in CD4-depleted animals and lower in CD4-depleted animals receiving a potently-RhCMV neutralizing IgG infusion, 2) humoral responses were generally delayed in CD4-depleted, acutely-infected dams, and 3) dams receiving passive IgG infusion before infection had high levels of RhCMV-specific IgG in the first week of infection (Fig 5).