Subsequent SARS-CoV-2 Infection in Healthcare Workers: A Retrospective Cohort Study in Iran
Yeganeh Karimi1,2, Arash Abdollahi3, Seyyed Amir Yasin Ahmadi4
1Faculty of Medicine, Iran University of Medical Sciences (IUMS), Tehran, Iran.
Immunity, Inflammation and Disease
|March 18, 2026
Summary
Vaccination significantly lowers the risk of subsequent SARS-CoV-2 infections in healthcare workers (HCWs). However, nurses and those in COVID-19 wards face higher risks of reinfection.
Area of Science:
- Infectious Diseases
- Epidemiology
- Occupational Health
Background:
- Rising SARS-CoV-2 variants increase COVID-19 prevalence globally.
- Healthcare workers (HCWs) face heightened risk of reinfection due to patient exposure.
- Understanding risk factors for HCW reinfection is crucial for infection control.
Purpose of the Study:
- To investigate risk factors associated with subsequent SARS-CoV-2 infections among HCWs.
- To differentiate between recurrence and reinfection in HCWs.
Main Methods:
- Retrospective study at a teaching hospital (March-October 2021).
- Online survey collected COVID-19 infection history from 601 HCWs.
- Generalized estimation equation used for multivariable prediction modeling.
Main Results:
- 90 subsequent SARS-CoV-2 infections observed in 72 HCWs (11.98%).
- Vaccination was associated with a reduced risk of subsequent infection.
- Nurses and HCWs in COVID-19 wards had double the risk of reinfection.
Conclusions:
- Subsequent SARS-CoV-2 infections are a significant concern for HCWs.
- Vaccination, occupation, and work location are critical factors influencing reinfection risk.
Keywords:
COVID‐19SARS‐CoV‐2healthcare workersoccupational riskpandemicpublic healthreinfectionrisk factorsvaccinationMore Related Videos
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