FIGURE 6.

Study of ZIKV replication in WT and IFNAR2 ^−/− lambs. One-month-old WT (n = 2) and IFNAR2 ^−/− (n = 2) ewe lambs were each inoculated intravenously with 2.0 × 10⁶ PFU of ZIKV PRVABC-59. As a control, an age- and sex-matched WT lamb was mock-infected. (A) The amount of viral genomic RNA, an indication of viral replication, was quantitated by qRT-PCR using the blood specimens taken daily for 19 days after infection. The amount of viral genomic RNA detected at 1-h post-infection serves as a reference for the viral inoculum. The amount of viral genomic RNA for each sample was determined based on a standard curve generated using a full-length infectious cDNA clone of ZIKV PRVABC-59. (B) Body weights were recorded daily and plotted as the changes in body weight relative to the initial value at day zero.