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ORIGINAL RESEARCH article

Front. Public Health
Sec. Infectious Diseases: Epidemiology and Prevention
Volume 12 - 2024 | doi: 10.3389/fpubh.2024.1480805

Rate, risk factors, and clinical outcomes of SARS-CoV-2 reinfection vs. primary infection in readmitted COVID-19 patients in Iran: a retrospective cohort study

Provisionally accepted
Mohammadamin Shahrbaf Mohammadamin Shahrbaf Yousef Alimohamadi Yousef Alimohamadi Reza Yousefi Arfaei Reza Yousefi Arfaei Mahmood Salesi Mahmood Salesi Morteza Izadi Morteza Izadi Mehdi Raei Mehdi Raei *
  • Baqiyatallah University of Medical Sciences, Tehran, Tehran, Iran

The final, formatted version of the article will be published soon.

    Background: Corona Virus Disease 2019 (COVID-19) has severely impacted global health, resulting in high morbidity and mortality, and overwhelming healthcare systems, particularly in Iran. Understanding reinfection is crucial as it has significant implications for immunity, public health strategies, and vaccine development. This study aims to identify rate and the risk factors associated with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) reinfection and compare the clinical course of initial infection versus reinfection in readmitted COVID-19 patients in Iran. Methods: This retrospective cohort study was conducted from January 2020 to the end of 2022 in five hospitals in Iran. The study compared demographic and clinical data, vaccination status, and clinical outcomes between patients with reinfection (defined as a positive PCR test for SARS-CoV-2 at least 90 days after the primary admission) and a control group (patients who had an initial confirmed SARS-CoV-2 infection but were not readmitted with a positive PCR test for SARS-CoV-2 at least 90 days after their primary infection). Risk factors for reinfection were evaluated using a regression model. Propensity score matching (PSM) was used to compare post-clinical and laboratory outcomes between the matched case and control groups. Results: Out of 31,245 patients, 153 (0.49%) experienced reinfections. The reinfection rate was significantly higher during B.1.617.2 and B.1.1.529 variant wave (p < 0.001). After multivariable regression analysis, incomplete vaccination status (OR: 1.68, 95% CI: 1.34-2.31, p = 0.021) and lack of booster vaccination (OR: 2.48, 95% CI: 1.96-3.65, p = 0.001) were the risk factors for reinfection. Furthermore, reinfection was associated with atypical COVID-19 symptoms, and shorter ICU and hospital stays (p < 0.001). The B.1.1.529 variant was significantly more common among reinfected patients (p < 0.001). Conclusion: SARS-CoV-2 reinfections are more frequently observed during waves of novel variants and are associated with a milder clinical course and shorter hospital stays. Full vaccination and booster doses can effectively reduce the risk of SARS-CoV-2 reinfections.

    Keywords: COVID-19, SARS-CoV-2, Reinfection, Vaccination, prevention

    Received: 14 Aug 2024; Accepted: 08 Oct 2024.

    Copyright: © 2024 Shahrbaf, Alimohamadi, Yousefi Arfaei, Salesi, Izadi and Raei. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Mehdi Raei, Baqiyatallah University of Medical Sciences, Tehran, 56131-56491, Tehran, Iran

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.