Upper airways of SARS-CoV-2 infected adult macaques have a profibrotic transcriptomic signature (A) Top five out of thirty-nine significantly enriched gene ontology (GO) pathways among upregulated genes in adult compared with infant macaques 14 days after SARS-CoV-2 infection. (B) Heat map of significantly differentially expressed genes from the Extracellular Matrix Component and Extracellular Matrix GO pathways. Assessment of protein gene product (PGP) 9.5 expression in (C) dam 1, (E) dam 2, (F) infant 1 and (D) infant 2, substance P (sub P) expression in (G) dam 1, (I) dam 2, (J) infant 1 and (H) infant 2 trachea tissues and (K) dam and (L) infant isotype controls via immunohistochemical staining.