The purpose — to establish the clinical and laboratory features of COVID-19 in patients who were hospitalized at the Republic Clinical Hospital for Infectious Diseases in Kazan and to identify predictors of severe disease and death. Material and methods. A comprehensive examination of 172 patients with coronavirus infection (COVID-19) was carried out. Patients were analyzed by gender, age, presence of vaccination against COVID-19, comorbidities, laboratory data — levels of lymphocytes, C reactive protein (CRP), ferritin, lactate dehydrogenase (LDH), D-dimer, fibrinogen, interleukin-6 (IL-6), and disease outcomes. Results. There were no gender differences in patients with respect to the severity of COVID-19, clinical manifestations, comorbidities, or disease outcome (p > 0.05). Severe and extremely severe forms of the disease among individuals vaccinated against COVID-19 were recorded significantly less frequently (p < 0.05). The predominant symptoms of coronavirus infection were weakness, fever, headache, cough, shortness of breath. Concomitant pathology was more often recorded with severe COVID-19 than with mild (p < 0.05). At admission, all patients had lymphopenia, elevated levels of CRP, ferritin, LDH, D-dimer, fibrinogen, and IL-6, the severity of which was significantly higher in severe COVID-19 and death (p < 0.01). Conclusion. Lymphopenia, hypofibrinogenemia, elevated levels of CRP, ferritin, LDH, IL-6, and D-dimer should be regarded as predictors of severe COVID-19 and death. Monitoring the dynamics of these blood biomarkers provides the individual approach to the management of patients with coronavirus infection.