Fig. 2

Protection efficacy against ZIKV challenge in pups born to dams immunized with Ad2-E, Ad2-prME, and Ad2-prME-NS1. a Schematic diagram of ZIKV challenge of pups born at 6 weeks after the completion of maternal immunization. The pups were challenged with 1.2 × 10³ PFU ZIKV via intraperitoneal injection at 1 day after birth. The male and female pups in each group were listed in Supplementary Table S3. Eighteen days after the challenge, pups were sacrificed. Unchallenged pups were used as healthy control. b The body weight of ZIKV-challenged pups. c The scores for neurological symptoms of ZIKV-challenged neonatal mice. The designation of neurological scores is described in Supplementary Materials and Methods. d, e The viral loads in the brain (n = 9–12 per group) (d) or testis (n = 5–6 per group) (e). Total RNA were extracted from the homogenates of the brain or testis. ZIKV genomic RNA was evaluated using one-step Q-PCR. The viral loads were expressed as the genome copy numbers per gram tissue. f Schematic diagram of ZIKV challenge of pups born at 15 weeks after the completion of maternal immunization. The pups were challenged as described above. Eighteen days after challenge, pups were sacrificed. Unchallenged pups were used as healthy control. g The body weight of ZIKV-challenged pups. h The scores for neurological symptoms of ZIKV-challenged pups. i, j The viral loads in the brain (n = 8–11 per group) (i) or testis (n = 3–5 per group) (j). The dotted lines indicate the limit of detection. The data were representative of two independent experiments and presented as mean ± SEM. Comparison between different groups were performed by one-way ANOVA. *p < 0.05; **p < 0.01; ***p < 0.001; ns no significance