Table 1.

Randomized controlled trials of COVID‐19 convalescent plasma reported to date

RCT identifier	Country	Recruitment (out of expected) (randomization strategy)	Control arm components	Median days from symptoms or hospital admission	Baseline recipient WHO score*	Median nAb in CCP units	Median nAb in recipient	Transfused CCP volume (ml)	Outcome	Refs
ChiCTR2000029757	China	103 (out of 200) (1:1)	BSC	30 (from symptoms)	5–6	not assessed	not assessed	200	Reduced mortality at day 28 only in WHO score 5 patients (HR 2·5)	[21]
NCT04342182 (ConCOVID)	Netherlands	86 (out of 426) (1:1)	BSC	10 (from symptoms)	5–6	1:160	1:160 in 79% of recipients	300	No benefit at day 15	[14]
CTRI/2020/04/024775 (PLACID)	India	464 (1:1)	BSC	6 (from symptoms)	4–5	1:40	1:90	200 + 200	No benefit at day 28	[13]
NCT04345523 (ConPlas‐19)	Spain	81 (out of 278, still recruiting) (1:1)	BSC	8 (from symptoms)	3 (25%) 4 (75%)	1:292	not assessed	250–300	Reduced mechanical ventilation or death (0% vs. 14%). Mortality rates were 0% vs. 9·3% at days 15 and 29 for the active and control groups, respectively.	[12]
NCT04375098	Chile	58 (1:1)	late CCP	6 (from symptoms)	3‐4	≥1:160	59% <1:160 (16% of patients enrolled before day 5 were ≥1:160 vs. 60% of those enrolled after day 6	200 + 200	NO benefit at day 30 in death, mechanical ventilation or prolonged hospitalization compared to CCP administration only in case of clinical worsening or >7 days after enrolment	[22]
NCT04479163	Argentina	160 (out of 210) (1:1)	normal saline	≤3 (from symptoms; and > 65 yrs)	3	Not assessed	Not assessed	250	Progression to severe COVID‐19 halved at day 30	[10]
NCT04383535 (PlasmAr)	Argentina	333 (2:1)	normal saline	8 (from symptoms)	5	1:300 IC80	Not assessed	500	No benefit at day 30 (16·2% vs. 31·2%)	[9]
CTRI/2020/05/025209	India	80 (1:1)	BSC	4·2 (from hospital admission)	5	Not assessed	Not assessed	200 + 200	Immediate mitigation of hypoxia, reduction in hospital stay as well as survival benefit was recorded in severe COVID‐19 patients with ARDS aged less than 67 years	[11]
NCT04356534	Bahrain	40 (1:1)	BSC	n.a.	4 (95%) 5 (5%)	Not assessed	Not assessed	200 + 200	No difference in requirement for ventilation, white blood cell count, LDH, CRP, troponin, ferritin, D‐dimer, procalcitonin, mortality rate at 28 days	[23]
NCT04346446	India	29 (1:1)	FFP	<3 (from symptoms)	4‐5	not assessed	not assessed	250 + 250	Better median improvement in PaO2/FiO2 at 48‐h [42 vs. 231] and at day 7	[24]
BKH‐CT‐012	Iraq	49 (1:1)	BSC	<3 (from ICU admission)	5	not assessed	not assessed	400	Duration of infection reduced by 4 days; mortality 1/21 in CCP arm vs. 8/28	[25]
RCT, randomized controlled trial; WHO, World Health Organization; nAb, neutralizing antibodies; CCP, COVID‐19 convalescent plasma; Ref, reference; BSC, best supportive care; FFP, fresh‐frozen plasma; n.a., not assessed; HR, hazard ratio; ARDS, acute respiratory distress syndrome; LDH, lactate dehydrogenase; CRP, C‐reactive protein; PaO2/FiO2, partial pressure of arterial oxygen to fraction of inspired oxygen ratio; ICU, intensive care unit. ‘Not assessed’ means that antivirus antibodies were assessed only using high‐throughput serology.
*The WHO score [20] ranges from 0 to 8: 0: no clinical or virological evidence of infection; 1: no limitations of activities; 2: limitations of activities; 3: hospitalized, no oxygen therapy; 4: oxygen by mask or nasal prongs; 5: non‐invasive ventilation or high‐flow oxygen; 6: intubation and mechanical ventilation; 7: ventilation + additional organ support ‐ pressors, renal replacement therapy, extracorporeal membrane oxygenation; and 8: death.
Here below, an alternative layout/adaptation of Table 1.

RCT identifier [Country]	Recruited (out of expected) [randomization strategy]	Control arm components	Median days from symptoms or hospital admission	Baseline recipient WHO score*	Median nAb in CCP units	Median nAb in recipient	Volume of CCP transfused (ml)	Outcome	Refs
ChiCTR2000029757 [China]	103 (of 200) [1:1]	BSC	30 (from symptoms)	5–6	n.a.	n.a.	200	Reduced mortality at day 28 only in WHO score 5 patients (HR 2·5)	[21]
NCT04342182 (ConCOVID) [Netherlands]	86 (of 426) [1:1]	BSC	10 (from symptoms)	5–6	1:160	1:160 in 79% of recipients	300	No benefit at day 15	[14]
CTRI/2020/04/024775 (PLACID) [India]	464 [1:1]	BSC	6 (from symptoms)	4–5	1:40	1:90	200 + 200	No benefit at day 28	[13]
NCT04345523 (ConPlas‐19) [Spain]	81 (of 278, still recruiting) [1:1]	BSC	8 (from symptoms)	3 (25%) 4 (75%)	1:292	n.a.	250–300	Reduced mechanical ventilation or death (0% vs. 14%). Mortality rates were 0% vs. 9·3% at days 15 and 29 for the active and control groups, respectively.	[12]
NCT04375098 [Chile]	58 [1:1]	late CCP	6 (from symptoms)	3–4	≥1:160	59% <1:160 (16% of patients enrolled before day 5 had ≥1:160 vs. 60% of those enrolled after day 6	200 + 200	No benefit at day 30 in death, mechanical ventilation or prolonged hospitalization compared to CCP administration only in case of clinical worsening or >7 days after enrolment	[22]
NCT04479163 [Argentina]	160 (of 210) [1:1]	Normal saline	≤ 3 (from symptoms; and >65 years)	3	n.a.	n.a.	250	Progression to severe COVID‐19 was halved at day 30	[10]
NCT04383535 (PlasmAr) [Argentina]	333 [2:1]	normal saline	8 (from symptoms)	5	1:300 IC80	n.a.	500	No benefit at day 30 (16·2% vs. 31·2%)	[9]
CTRI/2020/05/025209 [India]	80 [1:1]	BSC	4·2 (from hospital admission)	5	n.a.	n.a.	200 + 200	Immediate mitigation of hypoxia, reduction in hospital stay as well as survival benefit in severe COVID‐19 patients with ARDS aged < 67 years	[11]
NCT04356534 [Bahrain]	40 [1:1]	BSC	n.a.	4 (95%) 5 (5%)	n.a.	n.a.	200 + 200	No difference in requirement for ventilation, white blood cell count, LDH, CRP, troponin, ferritin and D‐dimer, procalcitonin, mortality rate at 28 days	[23]
NCT04346446 [India]	29 [1:1]	FFP	<3 (from symptoms)	4–5	n.a.	n.a.	250 + 250	Better median improvement in PaO2/FiO2 at 48 h (42 vs. 231) and at day 7	[24]
BKH‐CT‐012 [Iraq]	49 [1:1]	BSC	<3 (from ICU admission)	5	n.a.	n.a.	400	Duration of infection reduced by 4 days; mortality 1/21 in CCP arm vs. 8/28	[25]