Fig. 3: ZPIV reduced viral RNA levels in fetal tissues in marmosets.
The marmoset study scheme. Four marmosets, V1–V4, were i.m. injected with two doses of 5 ug alum/ZPIV 4 weeks apart. After co-housing with males, pregnancy and estimated gestational day (EGD) were determined by ultrasound examination. Individual marmosets became pregnant at different times after vaccination. Time-lapse between the last dose of vaccine and the time of virus challenge is indicated as a dotted line in (a). Unvaccinated control C1 and vaccinated V1–V4 marmosets were i.m. injected with two doses of 2.5 × 105 PFU ZK-BR 4 days apart during EGD 65–76 corresponding to 20, 24, 36, or 72 weeks after prime vaccination. Serum and urine samples were prepared at 0, 2, 9, and 14 days after infection (dpi) and viral RNA loads were determined in serum (b) and urine (c) using Real-Time qRT-PCR. All marmosets were sacrificed for examination at 14 dpi (EGD 79–89) and viral RNA levels in the placenta (d), fetal head (e), and fetal body (f) were determined. Three different locations in the placenta were sampled. RNA from each placental sample was prepared independently, and each sample was tested in duplicate. The asterisk indicates that one out of three locations in the placenta was positive for viral RNA (2.7 × 107 copy/g tissue) while the other two sites were negative for viral RNA. The mean of the three locations is presented. The number of fetuses per pregnant marmoset at each time point is indicated above the symbols in (e) and (f). The horizontal dotted lines indicate the limit of quantification per tissue, as described in Materials and Methods.
