IFNA1 and HIV infectious disease: Pathogenic SIV infection of nonnatural host species (e.g., rhesus or pig-tailed macaques) is, like HIV infection, associated with robust TI-IFN responses that persist indefinitely (27); conversely, TI-IFN responses rapidly normalize after acute nonpathogenic SIV infection of the African green monkey and sooty mangabey (28–30).