Background: Healthcare workers (HCWs) are particularly exposed to biological risk, including SARS-CoV-2 infection. In order to contrast the current pandemic and alleviate the burden of the disease on the healthcare system, a mass vaccination campaign against COVID-19 has been launched worldwide. Aim To evaluate the impact of COVID-19 vaccination in HCWs exposed to SARS-CoV-2, to describe the clinical presentation of COVID-19 in infected HCWs, and to investigate clinical and occupational risk factors for breakthrough infection. Design: Retrospective cohort study. Methods: The cohort of HCWs of Trieste Hospitals were followed up from 1 March 2020, to 30 November 2021 (21 months). All HCWs were periodically screened for SARS-CoV-2 infection by real-time PCR (RT–PCR) analysis. Clinical data were obtained through routine medical surveillance records. Risk factors for SARS-CoV-2 infection were investigated by univariable as well as multivariable logistic regression analysis. Results: Among 4394 HCWs routinely screened for SARS-CoV-2 by PCR on nasopharyngeal swab, a total of 800 incident cases were identified during the entire study period (1 March 2020 to 30 November 2021). Five hundred and sixty-four cases occurred before, and 236 after the start of the vaccination campaign against COVID-19, of whom 155 received a complete vaccination scheme before SARS-CoV-2 infection. Breakthrough infection was featured by mild or no symptoms and was significantly associated with the male sex, BMI > 25, and diabetes mellitus. Some categories of HCWs (physicians and nurse aids/auxiliary personnel) were at a higher risk of breakthrough infection. Conclusions: Fully vaccinated HCWs were less likely to acquire symptomatic as well as asymptomatic SARS-CoV-2 infection. Risk factors for SARS-CoV-2 infection after a full COVID-19 vaccination scheme included the male gender, diabetes mellitus, and overweight. HCWs with higher exposure to COVID-19 patients were at higher risk of breakthrough infection.
【저자키워드】 COVID-19, SARS-CoV-2, Vaccine, Healthcare workers, Breakthrough infection, occupational biological risk, 【초록키워드】 vaccination, pandemic, SARS-COV-2 infection, Infection, Diabetes Mellitus, Gender, risk, risk factor, healthcare worker, cohort study, Nasopharyngeal swab, Cohort, PCR, Asymptomatic, COVID-19 vaccination, Surveillance, Real-time PCR, HCWs, symptomatic, clinical, male, Mild, BMI, Analysis, Male sex, COVID-19 patient, Healthcare system, HCW, Factor, no symptom, higher risk, multivariable logistic regression, study period, Trieste, RT–PCR, Complete, evaluate, occurred, significantly, investigated, the disease, screened, less, category, alleviate, univariable, 【제목키워드】 Italy, Teaching, Factor, worker, Trieste,