Project description:Previous research has linked perceived social isolation (loneliness) to reduced antiviral immunity, but the immunologic effects of the objective social isolation imposed by pandemic “shelter in place” (SIP) policies is unknown. We assessed the immunologic impact of SIP by relocating 21 adult male rhesus macaques from 2000 sq-m field cage communities of 70-132 other macaques to 2 wks of individual housing in indoor shelters. SIP was associated with down-regulation of Type I interferon (IFN) antiviral gene expression. This effect emerged within the first 48 hrs of SIP, persisted for at least 2 wks, and abated within 4 wks of return to social housing. A subsequent round of SIP in the presence of a novel juvenile macaque abrogated this effect. These results identify a significant adverse effect of SIP social isolation on antiviral immune regulation in circulating immune cells and they suggest a potential behavioral strategy for ameliorating such effects by promoting pro-social engagement during SIP.