Clinical characteristics and risk factors for ZF2001 fully vaccinated inpatients with COVID-19: A retrospective cohort study.

The ZF2001 vaccine has demonstrated high efficacy in preventing coronavirus disease 2019 (COVID-19). However, the clinical characteristics of breakthrough infections in vaccinated individuals and the risk factors for adverse outcomes in COVID-19 patients remain unclear. We conducted a retrospective single-center cohort study at Xiangya Hospital of Central South University, including 210 fully vaccinated COVID-19 inpatients from December 5, 2022, to January 31, 2023. Data on clinical characteristics, laboratory findings, disease severity, treatment, and prognosis were collected and analyzed. Our findings revealed that COVID-19 inpatients still experienced common symptoms at the onset of illness, but most laboratory findings were within the normal range, except for white blood cell count (WBC), lymphocyte count, and lactate dehydrogenase (LDH) levels. Following standard treatment, 95.7% of patients were discharged from the hospital. We identified seven variables significantly associated with a higher risk of adverse outcomes, including age over 65, elevated WBC count, reduced lymphocyte count, higher levels of blood urea nitrogen (BUN), LDH, troponin, D-dimer, and procalcitonin. This study supports the substantial clinical benefits of the ZF2001 vaccine for COVID-19 patients. Additionally, age over 65, elevated WBC count, reduced lymphocyte count, and higher blood levels of BUN, LDH, D-dimer, and procalcitonin may be used as predictive factors for disease progression in fully vaccinated COVID-19 inpatients.