Fig 2. Maternal viral control and immune responses to ZIKV inoculation.

(A) Peripheral blood plasma viremia in pregnant macaques infected with ZIKV. Results are shown for animals infected at 38 days gestation (animal 827577, dark blue), 31 days gestation (animal 660875, light blue), 103 days gestation (animal 357676, red) or 118 days gestation (animal 598248, yellow). The day of gestation is estimated +/- 2 days. Grey tracings represent viremia in nonpregnant/male rhesus monkeys infected with the identical dose and strain of ZIKV in a previous study [28]. The horizontal line indicates the quantitative limit of detection. (B) Peripheral blood cell response to infection. Absolute numbers of Ki67+ NK cells (left) or CD8+TEM cells (right) are presented as a percentage relative to baseline set at 100% (dashed line), with first trimester and third trimester animals represented in the same colors as presented in Fig 1A. (C) Plasmablast expansion over time from each pregnant animal. The plasmablast expansions of two nonpregnant animals from Dudley et al [28] are shown as grey lines. (D) Neutralization by ZIKV immune sera from pregnant and nonpregnant ZIKV-infected macaques. Immune sera from macaques infected with ZIKV in either the first trimester (dark or light blue), third trimester (red or yellow), or nonpregnant contemporary controls (gray) from Dudley et al [28] were tested for their capacity to neutralize ZIKV-FP. Infection was measured by plaque reduction neutralization test (PRNT) and is expressed relative to the infectivity of ZIKV-FP in the absence of serum. The concentration of sera indicated on the x-axis is expressed as log₁₀ (dilution factor of serum). The EC90 and EC50, estimated by non-linear regression analysis, are also indicated by a dashed line. Neutralization curves for each animal at 28 dpi are shown.