To monitor the kinetics of the antiviral activity of IFNα subtypes, we treated cells either before infection (“pre”) or up to 8 h p.i. (“post”) and studied the antiviral activity by determining viral titers as TCID50 per milliliter and viral antigens by in-cell ELISA (icELISA) (Fig. 4 A and B). Here, IFNA1 is linked to infection.