Age-related rhesus macaque models of COVID-19

Yu, Pin; Qi, Feifei; Xu, Yanfeng; Li, Fengdi; Liu, Peipei; Liu, Jiayi; Bao, Linlin; Deng, Wei; Gao, Hong; Xiang, Zhiguang; Xiao, Chong; Lv, Qi; Gong, Shuran; Liu, Jiangning; Song, Zhiqi; Qu, Yajin; Xue, Jing; Wei, Qiang; Liu, Mingya; Wang, Guanpeng; Wang, Shunyi; Yu, Haisheng; Liu, Xing; Huang, Baoying; Wang, Wenling; Zhao, Li; Wang, Huijuan; Ye, Fei; Zhou, Weimin; Zhen, Wei; Han, Jun; Wu, Guizhen; Jin, Qi; Wang, Jianwei; Tan, Wenjie; Qin, Chuan

Virus load in the respiratory tract peaked at 3 dpi in both of YG and EG ( Figure 1A,B) . For young monkeys, the virus load in anal swabs was The percentage and counts of CD3 + CD8 + T cells, CD3 + CD4 + T cells were shown. YG (red line) and EG (blue line) were indicated in the upper right corner of each panel. All data are presented as mean ± SEM lower than that in the nasal and throat specimens ( Figure 1A) . Moreover, viral load from the anal swabs in EG was persistently detected from 3 dpi to 11 dpi, which is higher that in YG ( Figure 1B ). One monkey from each group was euthanized and necropsied at 7 dpi. Different lobes of lung were collected for detecting the viral loads. Approximate 104 Viral RNA copies/mL from the upper lung was detected in YG. As shown in Figure 1C , viral replication in EG monkeys was detected in all the lobes of lung with higher viral RNA copies (range from 104 to 107.5 copies/mL). The anterior-posterior thoracic x-rays from the young macaque showed ground-glass opacity and obscure lung markings in the upper lobe of the right lung at 7 dpi (Figure 2A ) and EG revealed no changes in the counts or percentages white blood cells ( Figure 3A ) and monocytes ( Figure 3B ), a notably higher average counts or percentage of lymphocytes was observed in YG than that in EG during the observation, but the decreased counts of lymphocytes was found both in YG and EG monkeys ( Figure 3C ). Furthermore, regarding the counts of CD3 + CD8 + T cells and CD3 + CD4 + T cells, the obvious decline in YG but not in EG was observed in Figure 3D .