Since the time of suppression of type I IFNs during viral infections coincides with the emergence of adaptive immune responses, particularly in infected tissues 14, 15, we here investigated whether the presence of virus particles or proteins that are opsonized by IgG antibodies, which are only present during late‐phase (or secondary) infections, function as an environmental cue to suppress type I and III IFN responses. The gene discussed is IFNA1; the disease is infection.