(Bloomberg) --

The U.S. Food and Drug Administration confirmed that an Emergency Use Authorization was granted for the use of Covid-19 convalescent plasma for the treatment of hospitalized patients, before an expected announcement by President Donald Trump.

Covid-19 convalescent plasma is collected from individuals whose plasma contains anti-SARS-CoV-2 antibodies.

The EUA was granted based on a review of historical evidence using convalescent plasma in prior outbreaks of respiratory viruses, certain preclinical evidence, results from small clinical trials conducted during the current outbreak and data from the ongoing National Convalescent Plasma Expanded Access Protocol, according to a letter posted on the FDA website.

Adequate and well-controlled randomized trials remain necessary for a definitive demonstration of efficacy and to determine the appropriate patient populations and optimal product attributes.

Trump is expected to announce the emergency authorization at a press conference later Sunday.

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