Tweet of the month: convalescent plasma transfusion to patients at the right time improves chances of recovery from coronavirus

Note by The Pundit: 

This efficacious transfusion therapy described by Houston doctors will be much faster reaching a wider set of people than vaccines can ever be.

This therapy, in principle, is ready to scale up for experimental use on a wide scale, as there is widespread existing experience with safe plasma transfusion. This existing experience shows that with standard precautions, transfusion is a safe therapy and thus the legal regulatory hurdles to deployment are minimal. The main challenges are the logistics of convalescent plasma collection from recovered patients and delivery of properly standardised plasma to hospitals.

The possibility of scaling up various monoclonal antibodies that achieve the same success is also well in hand but will take some extra months, and will have more significant regulatory hurdles to clear at the TGA, FDA and similar government agencies. But this Salazar et al. 2020 paper alone provides proof in principle that antibodies from whatever source with sufficient virus neutralising activity are an effective therapy if applied early to patients suffering COVID 19 symptoms.

• Note also, these findings combined with other vaccine trial data, strongly suggests vaccines will reduce epidemic damage.

Technical Summary:

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, has spread globally, and proven treatments are limited. Transfusion of convalescent plasma collected from donors who have recovered from COVID-19 is among many approaches being studied as potentially efficacious therapy. 

We are conducting a prospective, propensity score-matched study assessing the efficacy of COVID-19 convalescent plasma transfusion versus standard of care as treatment for severe and/or critical COVID-19. We present here the results of an interim analysis of 316 patients (n=316) enrolled at Houston Methodist hospitals from March 28 to July 6, 2020. Of the 316 transfused patients, 136 met a 28-day outcome and were matched to 251 non-transfused control COVID-19 patients. Matching criteria included age, sex, BMI, comorbidities, and baseline ventilation requirement 48 h from admission, and in a second matching analysis, ventilation status at Day 0. 

Variability in the timing of transfusion relative to admission and titer of antibodies of plasma transfused allowed for analysis in specific matched cohorts. 

The analysis showed a significant reduction (P = 0.047) in mortality within 28 days, specifically in patients transfused within 72 h of admission with plasma with an anti-spike protein receptor binding domain titer of ≥1:1350. These data suggest that treatment of COVID-19 with high anti-receptor binding domain (RBD) IgG titer convalescent plasma is efficacious in early-disease patients. 

Full paper:

Treatment of COVID-19 Patients with Convalescent Plasma Reveals a Signal of Significantly Decreased Mortality

Eric Salazar Paul A. Christensen Edward A. Graviss David W. Bernard Jimmy Gollihar James M. Musser

Open Access Published:August 10, 2020 DOI:https://doi.org/10.1016/j.ajpath.2020.08.001

Figure 2 is a stunner

Figure 2Kaplan-Meier curves for mortality within 28 days post-Day 0 for secondary matched cohorts. A. All secondary matched patients. B. Secondary matched patients transfused within 72 h of admission. C. Secondary matched patients transfused >72 h after admission. D. Secondary matched patients transfused within 72 h of admission with plasma with anti-RBD IgG titer ≥ 1:1350.