Clinical Study in the Treatment of Patients With Moderate Course of COVID-19

Inclusion Criteria: 1. Patients who are able to sign the informed consent form to partic-ipate in the clinical study; 2. Patients of both sexes at the age of 18-65 years of age; 3. Positive SARS-CoV-2 RNA test result obtained by PCR during the current episode of COVID-19 disease; 4. One or more clinical manifestations of ARI (acute respiratory infection) or patient complaints: cough (dry or scanty sputum), edema (including during exercise), chest congestion, sore throat, nasal congestion, or mild rhinorrhea, impairment or loss of smell (hyposmia or anosmia), loss of taste (dysgeusia), conjunctivitis, weakness, muscle pain, headache, vomiting, diarrhea, skin manifestations). 5. Patients with a moderate course of COVID-19, determined on the basis of at least one of the criteria specified in the Interim Guide-lines of the Ministry of Health (assessed from the moment of mani-festation of the disease symptoms): * Body Т \> 38 °C * RR \> 22/min * SpO2 \< 95 % (at the atmospheric air) * CRP of the blood serum \> 10 mg/L 6. CT changes typical of viral lesions (minimal or moderate lesion vol-ume; CT 1-2, no more than 72 hours before screening) 7. Patients meeting the requirements of the Clinical Study Protocol; 8. Negative pregnancy test (for women with preserved reproductive potential). Exclusion Criteria: 1. A history of allergic reactions to human blood products; 2. Allergic reactions to the components of the study drug; 3. Hypersensitivity to human immunoglobulin; 4. Positive direct Coombs test (antiglobulin test); 5. Condition requiring invasive oxygen support at Screening; 6. Subjects with mild, severe, extremely severe COVID-19, as well as those at an outpatient treatment and not scheduled for hospitali-zation; 7. Administration of blood products or blood derivatives within 3 months prior to enrollment; 8. Administration of any antiviral, immunomodulatory drugs after the manifestation of COVID-19 (except for those to be prescribed dur-ing the study / included in the standard therapy); 9. Pathology of the immune system (primary and secondary immu-nodeficiencies, deficiency of class A immunoglobulin (IgA) and / or the presence of IgA antibodies, autoimmune diseases); 10. Child Pugh class B and C liver cirrhosis; 11. Diabetes mellitus type 1. 12. Diseases of the thyroid gland with decompensation. 13. Signs of severe CNS lesions (past serious brain injury, meningitis, history of ischemic stroke, encephalopathy of various etiologies, epilepsy, etc.); 14. Serious blood diseases, current or in the history (for example, baseline anemia Hb \< 80, myeloid leukemia, myelodysplastic syn-drome, etc.); 15. The period after the coronary artery bypass grafting / stenting of at least 3 months prior to enrollment; 16. Malignant neoplasm of any localization at present or within 5 years before enrollment into the study, except for completely healed carcinoma in situ; 17. Conditions and diseases, other than COVID-19, known from anam-nesis, accompanied by blood hypercoagulability syndrome and a trend for thrombosis (such as sickle cell anemia, polycythemia, hemostatic disorders); 18. Severe dyslipidemia in the history; 19. Disseminated intravascular coagulation syndrome, thrombosis and thromboembolism of any localization, known from the history; 20. CKD-EPI GFR \< 30 mL/min at screening; 21. History of chronic III-IV FC heart failure; 22. Pregnancy or lactation; 23. Participation in any other clinical study within the last 3 months; 24. A history of tuberculosis, cancer or a positive reaction to HIV infec-tion, hepatitis B and C, syphilis according to the history; 25. Impossibility of intravenous administration of the drug; 26. Severe visual and/or hearing impairments, severe speech impair-ments and/or other abnormalities that may prevent the patient from adequate cooperation during the study); 27. Mental diseases in the history; 28. A history of alcohol, drug or medicinal product abuse; 29. Patients who, in the opinion of the investigator, are clearly or likely to be unable to understand and evaluate the information on this study within the informed consent signing process, in particular regarding the expected risks and possible discomfort; 30. Other diseases, symptoms or conditions not listed above that can be an obstacle to participation in a clinical study in the investiga-tor's opinion.