Speed of Endocytotic ZIKV-FP-Laden Vesicles Decreases the Most in Astrocytes. In astrocytes, the average speed of ZIKV-BR- and ZIKV-UG-laden vesicles significantly increased with longer hpi, whereas the speed of vesicles laden with ZIKV-FP significantly decreased. In neurons, the average vesicle speed exhibited the most prominent increase at 36 hpi, regardless of the virus strain, and then declined the most in ZIKV-FP-laden vesicles. In neuroblastoma SK-N-SH cells, the average speed of vesicles increased until 36 hpi, whereas in Vero E6 cells, the speed of virus-laden vesicles either decreased or remained unchanged. The number of analyzed cells is the same as in Figs 4, S2 and S3. Data were collected from one experiment, performed in duplicates and are represented as means ± SEM (One Way ANOVA, *p < 0.05). The average speed was calculated for the same vesicles as shown in Fig. 4.