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Convalescent plasma falls flat in first randomized trial
Plasma from individuals who have recovered from COVID-19 could benefit sick patients, but definitive evidence for or against convalescent plasma is still lacking. A consensus about how it should be deployed is beginning to emerge—and tools and insights to guide its use are becoming available.
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.