Figure 4.

Passive Protection in BALB/C mice using NHP plasma. (A) Cynomolgus ZIKV E specific IgG titers expressed as MFI from serum at day 0 (6 h after passive transfer of plasma) and day 14 after transfer. The negative assay cutoff was calculated by taking the mean value of negative control samples and adding 3 standard deviations and is shown by the dotted line. Differences between mice receiving control plasma and mice receiving low or high titer plasma were significant (p < 0.0001) at day 0, but not at day 14. (B) Viremia from six individual mice from each group at day 3 post-infection was determined using a standard plaque assay on Vero cells. Limit of detection is 50 pfu/mL, shown by the dotted line. Data points below the level of detection are depicted as 25. Differences between mice receiving control plasma and mice receiving low titer or high titer plasma were significant (^*p < 0.05). (C) Mouse ZIKV E specific IgG titers expressed as MFI. The negative cutoff was calculated by taking the mean value of negative control samples and adding 3 standard deviations and is shown by the dotted line. Differences between days 0 and 14 were significant (p < 0.05) in animals receiving control and low titer serum, but not high titer serum. (A–C): Error bars represent the Geometric Mean Titer (GMT)+/−95% Confidence Intervals. Statistical differences were assessed using the ANOVA with multiple comparisons.