Retrospective systematic analysis of incidence and severity of COVID-19 reinfection

Objective To investigate the incidence and severity of COVID-19 reinfection.

Methods We searched relevant studies on COVID-19 reinfection， including cohort study， case report， and cross-sectional study in PubMed， Embase， CNKI and Wanfang databases. Revman5.3.0 was used for statistical analysis.

Results A total of 52 studies in 19 countries were included. These literatures showed moderate and high quality. Furthermore， the pooled incidence of COVID-19 reinfection was estimated to be 1.9%（95%CI： 0.9%‒4.7%， P<0.01）， pooled incidence of reinfection among medical workers in hospitals and staff in nursing home was 13.8%（95%CI： 4.8%‒34.2%， P<0.01）， and pooled incidence of critical reinfection was 17.3%（95%CI： 11.5%‒25.9%， P<0.01）.Sensitivity and publication bias analysis showed that the pooled incidence was stable and no publication bias was identified.

Conclusion Incidence and severity of COVID-19 reinfection are both high. Although the prevention and control policy against COVID-19 has been adjusted in China， the public should pay attention to taking protective measures to avoid the reinfection.