India is the first country to complete a randomized controlled trial (RCT) of convalescent plasma in COVID-19. The study failed to demonstrate any improvement in survival or disease severity, but that outcome has not deterred proponents of the therapy. Preliminary evidence from other observational studies and from partially completed RCTs suggests that convalescent plasma may provide a benefit if it is administered early in the disease course and if it contains neutralizing antibodies against SARS-CoV-2 in sufficiently high titers (Table 1). Neither of these conditions prevailed in the PLACID clinical trial, which the Indian Council on Medical Research conducted across 39 hospitals.
Convalescent plasma was always positioned as an interim treatment to be superseded by more specific therapies, such as small molecules and monoclonal antibodies, as well as standardized hyperimmune globulin products, as and when they became available. But given the lack of options to treat patients with severe or life-threatening COVID-19, many physicians embraced convalescent plasma, despite an initial lack of evidence for its safety and its efficacy. In the United States, 105,819 patients were enrolled in an Expanded Access Program administered by the Mayo Clinic, which led to the granting of the US Food and Drug Administration (FDA) Emergency Use Authorization on 23 August. Off-label use of convalescent plasma is authorized in India. It is being tested widely elsewhere.
https://www.nature.com/articles/d41587-020-00020-0