Acute Respiratory Distress and Cytokine Storm in Aged, SARS-CoV-2 Infected African Green Monkeys, but not in Rhesus Macaques

SARS-CoV-2 induces a wide range of disease severity ranging from asymptomatic infection, to a life-threating illness, particularly in the elderly and persons with comorbid conditions. Among those persons with serious COVID-19 disease, acute respiratory distress syndrome (ARDS) is a common and often fatal presentation. Animal models of SARS-CoV-2 infection that manifest severe disease are needed to investigate the pathogenesis of COVID-19 induced ARDS and evaluate therapeutic strategies. Here we report ARDS in two aged African green monkeys (AGMs) infected with SARS-CoV-2 that demonstrated pathological lesions and disease similar to severe COVID-19 in humans. We also report a comparatively mild COVID-19 phenotype characterized by minor clinical, radiographic and histopathologic changes in the two surviving, aged AGMs and four rhesus macaques (RMs) infected with SARS-CoV-2. We found dramatic increases in circulating cytokines in three of four infected, aged AGMs but not in infected RMs. All of the AGMs showed increased levels of plasma IL-6 compared to baseline, a predictive marker and presumptive therapeutic target in humans infected with SARS-CoV-2 infection. Together, our results show that both RM and AGM are capable of modeling SARS-CoV-2 infection and suggest that aged AGMs may be useful for modeling severe disease manifestations including ARDS.