Risk of SARS-CoV-2 reinfection: a systematic review and meta-analysis

• Published in: Scientific reports Vol. 12; no. 1; p. 20763
• Main Authors: Deng, Luojia, Li, Peiqi, Zhang, Xuezhixing, Jiang, Qianxue, Turner, DeAnne, Zhou, Chao, Gao, Yanxiao, Qian, Frank, Zhang, Ci, Lu, Hui, Zou, Huachun, Vermund, Sten H, Qian, Han-Zhu
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 01.12.2022; Nature Publishing Group UK; Nature Portfolio
• Subjects: Case reports; COVID-19; COVID-19 - epidemiology; Health risks; Humans; Infections; Meta-analysis; PubMed; Reinfection - epidemiology; SARS-CoV-2; Severe acute respiratory syndrome coronavirus 2; Systematic review
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-022-24220-7

This meta-analysis aims to synthesize global evidence on the risk of reinfection among people previously infected with SARS-CoV-2. We systematically searched PubMed, Scopus, Embase and Web of Science as of April 5, 2021. We conducted: (1) meta-analysis of cohort studies containing data sufficient for calculating the incidence rate of SARS-CoV-2 reinfection; (2) systematic review of case reports with confirmed SARS-CoV-2 reinfection cases. The reinfection incidence was pooled by zero-inflated beta distribution. The hazard ratio (HR) between reinfection incidence among previously infected individuals and new infection incidence among infection-naïve individuals was calculated using random-effects models. Of 906 records retrieved and reviewed, 11 studies and 11 case reports were included in the meta-analysis and the systematic review, respectively. The pooled SARS-CoV-2 reinfection incidence rate was 0.70 (standard deviation [SD] 0.33) per 10,000 person-days. The incidence of reinfection was lower than the incidence of new infection (HR = 0.12, 95% confidence interval 0.09-0.17). Our meta-analysis of studies conducted prior to the emergency of the more transmissible Omicron variant showed that people with a prior SARS-CoV-2 infection could be re-infected, and they have a lower risk of infection than those without prior infection. Continuing reviews are needed as the reinfection risk may change due to the rapid evolution of SARS-CoV-2 variants.