*2.10. Fusion Assay*

Cells were cultured at subconfluent density in 12-well plates. Cell monolayers were cooled at 4 ◦C for at least 20 min in presence of cold MEM supplemented with 10% FBS. Pre-chilled cells were incubated at 4 ◦C with ZIKV at MOI of 1 in 1 mL of cold MEM supplemented with 10% FBS. After 1-h incubation, cells were shifted to 37 ◦C for another hour. Chloroquine was added to culture medium at 100 μM for a 2-h period. Next, culture medium was then replaced to avoid drug cytotoxic effects. Cells were harvested 30 h post temperature shifting for RNA extraction. Total RNA was subjected to RT-qPCR analysis as described.
