SARS-CoV-2 infection leads to a transient and acute type I/III IFN signature in the blood. (A) Principal-component analysis (PCA) of NanoString host response gene expression data from blood of 5 HC (red triangles) and 44 COVID-19 patients (spheres) followed longitudinally from diagnosis (V1, blue) for 4 wk (V2, green; V3, purple; and V4, orange). The percentage of variance captured by each principal-component (PC) axis is indicated, as well as the total variance. The vector position for each sample was plotted and the visualization was performed using Genomics Suite 7 (Partek). (B) Pathway analysis for the 123 DEGs between V1 and V2/V3/V4 determined using nSolver NanoString analysis software. The significance scores for the top 10 pathways are indicated. NLR, nucleotide oligomerization domain–like receptor. (C and D)Box and whisker plots (using the Tukey method) showing the expression score of the indicated pathways from V1 to V4 for patients and for HCs. A Kruskal–Wallis with uncorrected Dunn’s test was used for statistical analysis of data presented in this figure (multiple comparisons; ***, P < 0.001).(E) Correlation between the nasal SARS-CoV-2 normalized viral load and the NanoString IFN score (49 genes differentially expressed between V1 and V2/V3/V4). The Spearman's correlation coefficient is shown.