Comparative pathogenesis of COVID-19, MERS, and SARS in a nonhuman primate model

Coronavirus in nonhuman primates We urgently need vaccines and drug treatments for coronavirus disease 2019 (COVID-19). Even under these extreme circumstances, we must have animal models for rigorous testing of new strategies. Rockx et al. have undertaken a comparative study of three human coronaviruses in cynomolgus macaques: severe acute respiratory syndrome–coronavirus (SARS-CoV) (2002), Middle East respiratory syndrome (MERS)–CoV (2012), and SARS-CoV-2 (2019), which causes COVID-19 (see the Perspective by Lakdawala and Menachery). The most recent coronavirus has a distinct tropism for the nasal mucosa but is also found in the intestinal tract. Although none of the older macaques showed the severe symptoms that humans do, the lung pathology observed was similar. Like humans, the animals shed virus for prolonged periods from their upper respiratory tracts, and like influenza but unlike the 2002 SARS-CoV, this shedding peaked early in infection. It is this cryptic virus shedding that makes case detection difficult and can jeopardize the effectiveness of isolation. Science , this issue p. 1012 ; see also p. 942