Comparison of SARS-CoV-2 infections among 3 species of non-human primates

COVID-19, caused by SARS-CoV-2 infection, has recently been announced as a pandemic all over the world. Plenty of diagnostic, preventive and therapeutic knowledges have been enriched from clinical studies since December 2019. However, animal models, particularly non-human primate models, are urgently needed for critical questions that could not be answered in clinical patients, evaluations of anti-viral drugs and vaccines. In this study, two families of non-human primates, Old world monkeys (12Macaca mulatta, 6Macaca fascicularis) and New world monkeys (6Callithrix jacchus), were experimentally inoculated with SARS-CoV-2. Clinical signs were recorded. Samples were collected for analysis of viral shedding, viremia and histopathological examination. Increased body temperature was observed in 100% (12/12)M. mulatta, 33.3% (2/6)M. fascicularisand none (0/6) ofC. jacchuspost inoculation of SARS-CoV-2. All ofM. mulattaandM. fascicularisshowed chest radiographic abnormality. Viral genomes were detected in nasal swabs, throat swabs, anal swabs and blood from all 3 species of monkeys. Viral shedding from upper respiratory samples reached the peak between day 6 and day 8 post inoculation. From necropsiedM. mulattaandM. fascicularis, the tissues showing virus positive were mainly lung, weasand, bronchus and spleen. No viral genome was seen in any of tissues from 2 necropsiedC. jacchus.Severe gross lesions and histopathological changes were observed in lung, heart and stomach of SARS-CoV-2 infected animals. In summary, we have established a NHP model for COVID-19, which could be used to evaluate drugs and vaccines, and investigate viral pathogenesis.M. mulattais the most susceptible to SARS-CoV-2 infection, followed byM. fascicularisandC. jacchus.