SARS-CoV-2 immunity and functional recovery of COVID-19 patients 1-year after infection

Zhan, Yan; Zhu, Yufang; Wang, Shanshan; Jia, Shijun; Gao, Yunling; Lu, Yingying; Zhou, Caili; Liang, Ran; Sun, Dingwen; Wang, Xiaobo; Hou, Zhibing; Hu, Qiaoqiao; Du, Peng; Yu, Hao; Liu, Chang; Cui, Miao; Tong, Gangling; Zheng, Zhihua; Xu, Yunsheng; Zhu, Linyu; Cheng, Jin; Wu, Feng; Zheng, Yulan; Liu, Peijun; Hong, Peng

The long-term immunity and functional recovery after SARS-CoV-2 infection have implications in preventive measures and patient quality of life. Here we analyzed a prospective cohort of 121 recovered COVID-19 patients from Xiangyang, China at 1-year after diagnosis. Among them, chemiluminescence immunoassay-based screening showed 99% (95% CI, 98–100%) seroprevalence 10–12 months after infection, comparing to 0.8% (95% CI, 0.7–0.9%) in the general population. Total anti-receptor-binding domain (RBD) antibodies remained stable since discharge, while anti-RBD IgG and neutralization levels decreased over time. A predictive model estimates 17% (95% CI, 11–24%) and 87% (95% CI, 80–92%) participants were still 50% protected against detectable and severe re-infection of WT SARS-CoV-2, respectively, while neutralization levels against B.1.1.7 and B.1.351 variants were significantly reduced. All non-severe patients showed normal chest CT and 21% reported COVID-19-related symptoms. In contrast, 53% severe patients had abnormal chest CT, decreased pulmonary function or cardiac involvement and 79% were still symptomatic. Our findings suggest long-lasting immune protection after SARS-CoV-2 infection, while also highlight the risk of immune evasive variants and long-term consequences for COVID-19 survivors.