High-titer convalescent plasma reduces COVID-19 progression

Early administration of elevated-titer convalescent plasma against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was found to minimize the progression risk to severe respiratory disease by 48% in  older patients suffering from coronavirus.

A double-blind, randomized, placebo-controlled trial was performed to determine whether convalescent plasma with elevated titers of antibodies against SARS-CoV-2, administered within 72 hours after the onset of mild infection symptoms, would effectively prevent the advancement to severe disease in coronavirus disease 2019 (COVID-19)-infected geriatrics. 

This trial enrolled 160 older patients infected with the coronavirus. Participants were allocated to receive either a placebo (0.9% normal saline) or convalescent plasma with high antibody titers against SARS-CoV-2.

The major outcome was severe respiratory disorder (respiratory rate of 30 breaths/minute or more, an oxygen saturation of < 93% while the subject was breathing ambient air, or both). This analysis was terminated early at 76% of its projected sample size. This was due to a substantial decline in coronavirus cases in the study region and thus steady recruitment of participants was not possible. 

In the intention-to-treat population, the severe respiratory disease was found to develop in 16% (13/80) patients who were given convalescent plasma and 31% (25/80) patients (31%) who were given a placebo, with a relative risk decline of 48%.

In the time-to-event analysis, the median time to the development of severe respiratory disease in the convalescent plasma cohort was longer compared to the placebo cohort, as shown in the following figure:

A modified intention-to-treat assessment that excluded six subjects who had a primary end-point event prior to infusion illustrated a greater effect size. No vital adverse effects were witnessed. 

Early high-titer plasma therapy aids in the prevention of severe COVID-19 in older patients.