Interferon (IFN) mRNA response in A3 (immortalised human normal trophoblasts) and Jar (human choriocarcinoma) cell lines infected with two different Rift Valley fever virus (RVFV) strains. The cell lines were infected at a multiplicity of infection of 1 and cell lysates were harvested at 0 h and at 6 or 24 h post-infection (hpi). Total cellular RNA was extracted from harvested cell lysate and used for detection of IFNα1 (A), IFNβ1 (B), IFNγ (C), and IFNλ (D) RNA using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) with TaqMan® FAM/MGB probe assays. Experiments were performed in triplicate and repeated twice. The symbol plus error bar indicates the mean ± standard deviation. Statistical significance was determined by one-way analysis of variance (ANOVA) plus Dunnett’s post hoc analysis. The data from 24 hpi was used for multiple group comparisons and the significance of p values is indicated by the asterisks; red line = mock vs. wt ZH548; green line = mock vs. ΔNSs::Katushka; black line = wt ZH548 vs. ΔNSs::Katushka (* p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001, NS = not significant).