Five matching blood donors were found for the five blood donors, three men, and two women. The donors were between 18 and 60 years old. Around two-quarters of a liter of purified and tested blood plasma was transferred to the intensive care patients twice on the same day. The patient’s values were monitored very closely – one reason why this small, uncontrolled study made it into one of the most respected medical journals. In almost all patients, the fever subsided rapidly within a day or two. From day seven after treatment to day 12, the condition improved considerably, so that soon all five patients were discharged in good health. The Sars CoV-2 tests also provide a decisive indication of the effectiveness of the immunization:
And there is one more thing that encourages doctors: when the antibodies are given, the patient’s immune system may have been stimulated to produce their own effective antibodies. The result was similar for a similar blood transfusion study by Chinese doctors from the National Research Center for Translational Medicine at Ruijin Hospital in Shanghai. Ten critically ill Covid-19 patients between the ages of 45 and 60 were treated in February. The study published in the preprint server MedRxiv has not yet been reviewed and published in a scientific journal, but the description of the doctors is similar to that from Shenzhen: hardly any side effects and clear immunological effects. In this case, the course of treatment was subsequently compared with the courses of patients, who were treated without passive immunization. Nevertheless: This is also not a controlled study that meets minimum standards for approval and therefore does not allow any causal, valid statements on the effectiveness of the therapy.
Caution is particularly important because the small number of Covid-19 patients treated in China alone does not allow any conclusions to be drawn about possible complications. Allergic reactions, especially in the lungs after the blood transfusion, are quite possible, depending on the treatment and testing of the donor blood. The transfusion doctors in the “Jama” warn of this. The “Journal of Clinical Investigation” points out that the donated immune cells also cause the immune system of Covid-19 patients to overreact themselves – a phenomenon known as the “Antibody-dependent enhancement of infection (ADE effect)”. In addition, it remains unclear how much donor blood is required for therapeutic success. While people infected with the new coronavirus form hundreds of different antibodies, including clearly “neutralizing” antibodies that attack the pathogen. But not all are equally active and passive vaccination could also activate immune cells, which in theory even provokes complications.
However, there is a noticeable growing willingness among experts to quickly remove such uncertainties. So far, no one has actively advocated using passive vaccination prophylactically or in the early stages of Covid 19 disease (where it works best based on historical experience), but the hope of helping at least seriously ill patients is clearly growing. Now it is a question of how blood banks, transfusion doctors and infectiologists in the clinics build the necessary infrastructure and how recovered patients can be motivated to donate blood.