The US Food and Drug Administration has granted an emergency authorisation to use donated blood plasma from covid-19 survivors to treat the disease, but the evidence that it works is lacking
Source:
https://www.newscientist.com/article/2252737-convalescent-plasma-treatment-for-covid-19-has-been-oversold-by-the-us/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home