Yousef Alimohamadi - Health Research Center, Life Style Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
Kiana Bahani - Department of Epidemiology and Biostatistics School of public health, Tehran University of Medical Science, Tehran, Iran
Kolsoom Alimohammadi - Health Research Center, Life Style Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
Mojtaba Sepandi - Health Research Center, Life Style Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran

Backgrounds: Reinfection among COVID-۱۹ patients is still a challenging issue in the medical literature. Therefore, the current meta-analysis was conducted to estimate the pooled incidence rate of reinfection among COVID-۱۹ patients. Materials & Methods: A comprehensive search was conducted in PubMed, Web of Science, and Scopus databases from July ۱ to October ۱, ۲۰۲۱. Original studies which estimated the incidence rate of COVID-۱۹ reinfection were included. CASP (Critical Appraisal skills program) was used to assess the quality of studies. Data were analyzed by STATA statistical software Version ۱۵ (StataCorp, College Station, TX, USA). Findings: A total of ۳۸۰۳ articles were found, of which ۱۶ articles remained after title, abstract, and full text screening. The minimum and maximum incidence rates of reinfection were ۰.۰۰۱ and ۰.۷۳%, respectively. The pooled estimated incidence rate of COVID-۱۹ reinfection was ۰.۱۱% (۹۵% confidence interval: ۰.۰۲-۰.۲۰, p< .۰۰۱, I۲ = ۱۰۰.۰). The highest pooled estimated incidence rate of reinfection was observed in people <۵۰ years old (۰.۱۴%) (۹۵% CI: ۰.۰۰۱-۰.۳۴, p<.۰۰۱, I۲ = ۱۰۰). Regarding the time elapsed after the first infection, the highest reinfection rate occurred four months after the first infection (۰.۱۲%) (۹۵% CI: ۰.۰۰۱-۰.۲۷, p< .۰۰۱, I۲ = ۱۰۰). Conclusion: The incidence rate of reinfection among COVID-۱۹ patients is expected to be high. However, it seems that the influence of factors including the age of patients and the time elapsed after the first infection must be considered.

COVID-۱۹, Reinfection, Treatment Failure, Meta-analysis