A small study of patients who were severely ill from the coronavirus hints that treatment with antibodies from recovered patients may modestly help recovery and survival, scientists reported on Friday [May 22].
… Thirty-nine hospitalized patients were given intravenous infusions of antibodies from patients who had recovered from the condition.
The course of illness in patients who received the convalescent plasma was compared to that of similar patients identified through electronic health records who did not get the treatment.
This is a weak form of comparison, prone to error. And researchers are wary of studies that take place at a single institution, because the results often are not applicable to patients elsewhere.
Researchers at the Icahn School of Medicine at Mount Sinai in New York reported that 18 percent of those who got the plasma of convalescent serum became sicker, compared with 24.3 percent of the patients identified through medical records.
Analyses like these are fraught with difficulties. The only way to know for sure if the treatment works is to randomly assign patients to receive antibodies or a placebo.
And it can be impossible to find many patients who agree to have their treatment randomized to an unknown treatment, noted Dr. Arturo Casadevall of the Johns Hopkins School of Medicine in Baltimore.