Mayo Clinic researchers reported a strong hint that blood plasma from COVID-19 survivors helps other patients recover, but it's not proof and some experts worry if, amid clamor for the treatment, they'll ever get a clear answer.
More than 64,000 patients in the U.S. have been given convalescent plasma, a century-old approach to fend off flu and measles before vaccines. It's a go-to tactic when new diseases come along, and history suggests it works against some, but not all, infections.
The problem: This wasn't a formal study. The patients were treated in different ways in hospitals around the country as part of a Food and Drug Administration program designed to speed access to the experimental therapy.
"For 102 years we've been debating whether or not convalescent plasma works," said Dr. Mila Ortigoza of New York University, referring to plasma's use in the 1918 flu pandemic. This time around, "we really need undisputable evidence."
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