TUESDAY, Aug. 24, 2021 (HealthDay News) -- Infusion of COVID-19 convalescent plasma with a high titer of antibodies does not prevent COVID-19 progression in outpatients at high risk for severe disease, according to a study published online Aug. 18 in the New England Journal of Medicine.
Frederick K. Korley, M.D., Ph.D., from the University of Michigan in Ann Arbor, and colleagues enrolled patients aged 50 years or older with one or more risk factors for disease progression, who presented to the emergency department within seven days after COVID-19 symptom onset. The patients were randomly assigned to receive one unit of convalescent plasma with a high titer of antibodies against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) or placebo (257 and 254 patients, respectively).
The median titer of SARS-CoV-2 neutralizing antibodies was 1:641 in the donor plasma samples. The researchers found that disease progression occurred in 30.0 and 31.9 percent of patients in the convalescent plasma and placebo groups, respectively (posterior probability of superiority of convalescent plasma, 0.68). Death occurred in five patients in the plasma group and one in the placebo group. The two groups had similar outcomes regarding worst illness severity and hospital-free days.
"The results show that convalescent plasma does not appear to benefit this particular group," a coauthor said in a statement. "But the findings answer an important clinical question and may help bring researchers a step closer to finding more effective treatments against this devastating disease."
Several authors disclosed financial ties to the biopharmaceutical industry; two authors disclosed holding patents.