Convalescent plasma for Covid-19 may not be as effective as hoped

 Here's a recent article from the New England Journal of Medicine: they conclude that treatment of Covid-19 patients with convalescent plasma is no better than a placebo treatment (for a group of seriously ill patients with over a 10% mortality rate).

A Randomized Trial of Convalescent Plasma in Covid-19 Severe Pneumonia

by Ventura A. Simonovich, M.D., Leandro D. Burgos Pratx, M.D., Paula Scibona, M.D., María V. Beruto, M.D., Marcelo G. Vallone, M.D., Carolina Vázquez, M.D., Nadia Savoy, M.D., Diego H. Giunta, M.D., M.P.H., Ph.D., Lucía G. Pérez, M.D., Marisa del L. Sánchez, M.D., Andrea Vanesa Gamarnik, Ph.D., Diego S. Ojeda, Ph.D., et al., for the PlasmAr Study Group

RESULTS: A total of 228 patients were assigned to receive convalescent plasma and 105 to receive placebo. The median time from the onset of symptoms to enrollment in the trial was 8 days (interquartile range, 5 to 10), and hypoxemia was the most frequent severity criterion for enrollment. The infused convalescent plasma had a median titer of 1:3200 of total SARS-CoV-2 antibodies (interquartile range, 1:800 to 1:3200]. No patients were lost to follow-up. At day 30 day, no significant difference was noted between the convalescent plasma group and the placebo group in the distribution of clinical outcomes according to the ordinal scale (odds ratio, 0.83 (95% confidence interval [CI], 0.52 to 1.35; P=0.46). Overall mortality was 10.96% in the convalescent plasma group and 11.43% in the placebo group, for a risk difference of −0.46 percentage points (95% CI, −7.8 to 6.8). Total SARS-CoV-2 antibody titers tended to be higher in the convalescent plasma group at day 2 after the intervention. Adverse events and serious adverse events were similar in the two groups.

CONCLUSIONS: No significant differences were observed in clinical status or overall mortality between patients treated with convalescent plasma and those who received placebo. 

HT: Irene Wapnir