Interestingly, the ΔNS1 elicited production of both IFNα and IFNβ was indistinguishable from that of the parent rPVM; ΔNS2 and ΔNS1ΔNS2 gene-deleted viruses elicited higher levels of both IFNα and IFNβ than the parent rPVM at early time points during infection. Here, IFNB1 is linked to infection.