新型冠状病毒重复感染流行病学研究进展

新型冠状病毒Omicron变异株持续突变演化，新亚型免疫逃逸能力不断增强，重复感染风险增加，且两次感染时间间隔可能缩短。与初始感染相比，尽管重复感染的临床表现较轻、重症/死亡风险降低，但仍可造成超额健康风险。重复感染的发生与疫苗接种状态、个体免疫水平、年龄、职业及居住类型等因素密切相关。未及时接种疫苗者、老年人及合并多种基础疾病者尤其是初始感染的重症/危重症者为重复感染重症发生的高危人群。及时接种新型冠状病毒疫苗可在自然感染基础上对重复感染及重症提供额外保护；此外，口罩仍是抵御新型冠状病毒感染的有效工具。

Progress in research of epidemiology of 2019-nCoV reinfection

Continuous evolution of Omicron variant of 2019-nCoV has resulted in a rapid and simultaneous emergences of novel sub-variants with increased immune escape ability, higher reinfection risk and shorter time interval between infections. Compared with the first infection, the reinfection would still pose exceed risk to people''s health although the clinical manifestations of the reinfection might be milder and the risk for severe illness or death is lower. The reinfection is highly associated with people''s vaccination status, immunity level, age, working and residential factors. Those who have not received 2019-nCoV vaccination, the elderly and those with comorbidities, especially the previous 2019-nCoV patients with severe/critical illness, are at high risk for the reinfection. Booster doses of vaccine might play an additional role in the prevention of the reinfection and severe illness on the basis of natural immunity.