Reflection on passive immunotherapy in those who need most: some novel strategic arguments for obtaining safer therapeutic plasma or autologous antibodies from recovered COVID -19 infected patients

The COVID-19 pandemic is an emerging new human disease, for which no vaccines, or monoclonal antibodies (mAbs) or drugs, are currently available for therapy. Active vaccination requires the induction of an immune response against a given agent in a susceptible individual for the pur- pose of preventing or treating an infectious disease and this usually takes time to develop. Thus, the use of existing autol- ogous Ab administration, obtainable from recovered COVID-19 patients two weeks after recovery, is the best and the most practical strategy for providing immediate passive immunity to susceptible recipients in need. Recently, the use of convalescent blood-derived products was proposed by one of the authors of this paper (JS) as an early option for treating patients with Ebola virus disease. In this mini-report we propose three potential additional options for sources of such autologous Ab and provide some operational and evidence-based arguments to support the urgent implementation of such strategic approaches to saving the lives of those in need: (i) the use of hyperimmune immunoglobulin concentrates, which are derived from the plasma of physiologically immunized donors. It is debatable that this method may be even more effective than plasma- pheresis since it uses a smaller dose of about 200 ml, which causes higher donor variability compared to the product of plasmapheresis which provides 600 ml that can be used as a triplet of satellite bags for three recipients.