TABLE 2.

Data related to efficacy of COVID‐19 convalescent plasma from randomized clinical trials and a large observational study

Author	Study design	CCP arm N	Control arm N	CCP titer	Control	Patient population	Timing of intervention	Primary endpoint	Efficacy CCP (ITT)
Li L 19	RCT open label	52	51	High titer IgG against S‐RBD	Standard of care	Adults with severe or life‐threatening COVID‐19	Median of 30 days between onset of symptoms and randomization	Clinical improvement within 28 days	51.9% CCP vs. 43.1% control met primary endpoint (HR 1.40 (95% CI 0.79–2.49; p = .26)
Agarwal A 31	RCT open label	235	229	Inconsistent	Standard of care	Adults with moderate COVID‐19	Inconsistent	Composite of progression to severe disease or all‐cause mortality by day 28	19% CCP vs. 18% control met primary endpoint (RR 1.04; 95% CI 0.71–1.54)
Salman OH 17	RCT open label	15	15	Inconsistent	Standard of care	Adults with moderate or severe COVID‐19	Median of 17 days from onset of illness to hospitalization. Median of 13 days from hospitalization to randomization	At least 50% improvement of the severity of illness at any time during 5‐ day study period	Gradual decrease in illness severity during the study period in CCP group, p < .001, compared to baseline value. No difference seen in control group
Rasheed AM 16	RCT open label	21	28	High titer IgG (SARS‐CoV‐2 IgG index >1)	Standard of care	Critically ill adults with COVID‐19	Mean 15 (CP) to 17 (control) days after onset of infection to randomization	Improvement in clinical status and mortality	Recovery time from critical illness 4.52 days for CCP vs. 8.45 days for control (p < .0001); Mortality was 1/21 (CCP) vs. 8/28 in control group.
Simonovich VA 18	RCT Double blind	228	105	High titer IgG against SARS‐CoV‐2	Normal saline	Adults with COVID‐19 and severe pneumonia	Median of 8 days between onset of symptoms and randomization	Clinical status 30 days after intervention using WHO 6‐point disease severity scale	No significant difference noted between CCP and control group in the distribution of clinical outcomes (OR 0.83; 95% CI 0.52–1.35; p = .46)
Libster R 13	RCT Double blind	80	80	High titers ‐ upper 28th percentile of units tested	Normal saline	65–74 yo with comorbidities or > =75 yo	<72 h between onset of symptoms and transfusion	Severe respiratory disease	16% CCP vs. 31% control met primary endpoint (RR 0.52; 95% CI).29–0.94; p = .03)
Joyner MJ 14	Observational	3082	NA	Data stratified by low, middle and high titer CCP	NA	Adults with severe or life‐threatening COVID‐19	Data stratified by less than and greater than 72 h of admission	30‐day all‐cause mortality	Among 2014 patients non‐ventilated patients, 22.2% in low‐titer cohort met the end‐point vs. 14.2% in the high‐titer cohort (relative risk, 0.75). CCP showed no benefit among patients who received mechanical ventilation (relative risk, 1.02)

Abbreviations: CCP, COVID‐19 convalescent plasma; ITT, intention to treat; NA, not available; OR, odds ratio; RCT, randomized controlled trial; RR, relative risk.