The clinical trial aims to study the safety and efficacy of transfusion of COVID-19 convalescent hyperimmune plasma for the treatment of moderate and severe forms of COVID-19 disease in comparison with non-convalescent fresh frozen plasma (standard plasma).

This is a study of the safety and efficacy of the use of COVID-19 convalescent plasma (from subjects who have recovered from SARS-CoV-2) in the treatment of moderate and severe forms of the SARS-CoV-2 infection. Currently, there are no registered drugs for the treatment of the SARS-CoV-2 infection in the world. The use of hyperimmune plasma is a well-known method used for many decades to treat many dangerous infections. The effectiveness of such a therapy for COVID-19 patients has recently been demonstrated in a number of clinical studies in China. Therefore, we plan to study the feasibility of administering multiple doses of COVID-19 convalescent plasma in comparison with standard plasma to moderate and severe patients with COVID-19.

Inclusion Criteria:

1. Men or women aged 18-75 years.
2. The presence of COVID-19 infection, confirmed by PCR testing
3. The presence of the COVID-19 pneumonia pattern on the chest HRCT with a damage to more than 25% of the lung parenchyma
4. Morning fever ≥ 38.0 °C over the last three days
5. CRP blood level ≥ 50 mg / ml or ferritin blood level ≥ 600 μg / ml
6. A signed informed consent

Exclusion Criteria:

1. Respiratory index ≤200
2. Contraindications for the transfusion of donor immune plasma or history of prior reactions to blood transfusions
3. Mechanical ventilation
4. The presence of chronic lung diseases with chronic respiratory failure.
5. The need for home continuous oxygen therapy before the onset of current disease.
6. Serum creatinine level higher than 150 μmol / l
7. Pregnancy or breastfeeding

There is no current plan to share individual participant data (IPD).