Experiences in the use of multiple doses of convalescent plasma in critically ill patients with COVID-19

At the beginning of the SARS-CoV-2 pandemic, transfusion of COVID-19 convalescent plasma (CCP) was considered as one of the possibilities to help severe patients to overcome COVID-19 disease. The use of CCP has been controversial as its effectiveness depends on many variables from the plasma donor and the COVID-19 patient, for example, time of convalescence or symptoms onset. This was a feasibility study assessing the safety of multiple doses of CCP in mechanically ventilated intubated patients with respiratory failure due to COVID-19. Thirty (30) patients with severe respiratory failure, in ICU, with invasive mechanical ventilation received up to 5 doses of 300 to 600 ml of CP on alternate days (0,2,4,6 and 8) until extubation, futility, or death. Nineteen patients received five doses, seven received four, and four had 2 or 3 doses. On day 28 of follow-up, 57% of patients recovered and were at home and the long-term mortality observed was 27%. The ten severe adverse events reported in the study were unrelated to CCP transfusion. This study suggests that transfusion of multiple doses of convalescent plasma (CP) is safe. This strategy may represent an option to use in new studies, given the potential benefit of CCP transfusions in the early stage of infection in unvaccinated populations and in settings where monoclonal antibodies or antivirals are contraindicated or not available. Summary box Transfusion of multiple doses (up to 5 doses) of 300-600 ml of convalescent plasma from COVID-19 recovered patients is safe as it does not induce more severe effects than a single dose. Independent of the number of transfused doses, most patients had detectable levels of total and neutralizing antibodies in plasma. Future studies are needed to determine if multiple transfusion doses are more efficient in preventing severity than a single dose.