Figure 6.

Infection phenotypes of ZIKV variants in neonatal mice. One-day-old pups (control: n = 19; ZIKV variants: n = 8–29) were inoculated with either 10² or 10⁴ TCID₅₀ of ZIKV. (A,B) Mean clinical scores: 0—no visible abnormalities; 1—mild ataxia and/or tremors; 2—obvious ataxia and/or tremors; 3—depression, hunching, reluctance to walk, and falling to the side when walking; 4—obvious hyperactivity; 5—close to moribund but still somewhat responsive; 6—paralysis; 7—death. (C,D) Percentage of survival. (E,F) ZIKV loads in brains sampled at 21 days after inoculation or death. (G,H) ZIKV-specific IgG Ab titers in blood plasma at 21 days after inoculation; quantified by immunoperoxidase monolayer assay—IPMA. Asterisk (*) denotes statistically significant difference compared to the WT ZIKV group. Dotted lines represent the LOD, solid lines represent mean values.