More on convalescent plasma for treating Covid-19

Early results concerning the effectiveness of convalescent plasma have been mixed.  Here's a new study, in the NEJM, and reported in the NY Times. (see my earlier posts here.)

Here's the Times story:

Blood Plasma Reduces Risk of Severe Covid-19 if Given Early  By Katherine J. Wu

"A small but rigorous clinical trial in Argentina has found that blood plasma from recovered Covid-19 patients can keep older adults from getting seriously sick with the coronavirus — if they get the therapy within days of the onset of the illness.

"The results, published Wednesday in the New England Journal of Medicine, are some of the first to conclusively point toward the oft-discussed treatment’s beneficial effects."

And here's the NEJM article:

Early High-Titer Plasma Therapy to Prevent Severe Covid-19 in Older Adults

List of authors.

Romina Libster, M.D., Gonzalo Pérez Marc, M.D., Diego Wappner, M.D., Silvina Coviello, M.S., Alejandra Bianchi, Virginia Braem, Ignacio Esteban, M.D., Mauricio T. Caballero, M.D., Cristian Wood, M.D., Mabel Berrueta, M.D., Aníbal Rondan, M.D., Gabriela Lescano, M.D., et al., for the Fundación INFANT–COVID-19 Group*

"BACKGROUND: Therapies to interrupt the progression of early coronavirus disease 2019 (Covid-19) remain elusive. Among them, convalescent plasma administered to hospitalized patients has been unsuccessful, perhaps because antibodies should be administered earlier in the course of illness.

METHODS: We conducted a randomized, double-blind, placebo-controlled trial of convalescent plasma with high IgG titers against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in older adult patients within 72 hours after the onset of mild Covid-19 symptoms. The primary end point was severe respiratory disease, defined as a respiratory rate of 30 breaths per minute or more, an oxygen saturation of less than 93% while the patient was breathing ambient air, or both. The trial was stopped early at 76% of its projected sample size because cases of Covid-19 in the trial region decreased considerably and steady enrollment of trial patients became virtually impossible.

RESULTS: A total of 160 patients underwent randomization. In the intention-to-treat population, severe respiratory disease developed in 13 of 80 patients (16%) who received convalescent plasma and 25 of 80 patients (31%) who received placebo (relative risk, 0.52; 95% confidence interval [CI], 0.29 to 0.94; P=0.03), with a relative risk reduction of 48%. A modified intention-to-treat analysis that excluded 6 patients who had a primary end-point event before infusion of convalescent plasma or placebo showed a larger effect size (relative risk, 0.40; 95% CI, 0.20 to 0.81). No solicited adverse events were observed.

CONCLUSIONS: Early administration of high-titer convalescent plasma against SARS-CoV-2 to mildly ill infected older adults reduced the progression of Covid-19. "