A. A549 cells were treated with IFN-α (100 U/mL), IFN-λ (200 ng/mL) or IFN-γ (10 U/mL) for 6 hrs after which they were infected with ZIKV (MOI=3) for 18 hrs (Pre-treatment). Alternatively, cells were first infected with ZIKV for 6 hrs followed by treatment with IFN for 12 hrs (Post-treatment). Total RNA was isolated and levels of ZIKV genomic RNA were determined by qRT-PCR. Values are expressed as mean ± standard error. *P<0.05, **P<0.01 (Student's t-test); N=3 