OAS3 and infection: However, during infection of RoNi/7 cells with VACVΔE3L, as we previously found in human A549 cells, degradation of rRNA occurred to a similar extent in the absence of OAS1 and OAS2 as in WT cells and virus replicated to the same extent in OAS1-KO, OAS2-KO, and WT RoNi cells (Fig. 9), suggesting that only OAS3 played a role in antiviral activity.