Convalescent plasma lowers Covid-19 death risk

A phlebotomist shows Melissa Cruz the full bag of her donated convalescent plasma, which she donated after recovering from coronavirus (COVID-19) contracted during her work as an ER technician, at the Central Seattle Donor Center of Bloodworks Northwest during the outbreak in Seattle, Washington, U.S. April 17, 2020. The plasma from recovered patients will be used in an experimental treatment study for current coronavirus patients. REUTERS/Lindsey Wasson

Infusions of antibody-rich blood plasma from people who have recovered from the new coronavirus, known as convalescent plasma, can lower the risk of death for hospitalized Covid-19 patients, according to a pooled analysis of data from eight earlier studies of more than 700 hospitalized patients around the world.

Researchers found that mortality rates were roughly 13% in patients who received convalescent plasma versus about 25% for those who did not get the treatment.

Convalescent plasma was shown to be safe in an earlier study of 5,000 hospitalized adults with severe or life-threatening Covid-19.

In that study, fewer than 1% of patients had any serious adverse effects in the first four hours after transfusion.

The current study could not account for differences in factors such as how sick patients were, how much plasma they received, how long they were sick before the received it, and how long doctors followed them afterward.

“Given the safety of plasma administration in Covid-19 patients, the results … provide encouragement for its continued used as a therapy,” the researchers write in a report published ahead of peer review.