With few treatment options, more than 500,000 patients with COVID-19 were transfused with convalescent plasma in the United States. Observational data from over 3,000 patients transfused under the Expanded Access Program suggested that high-titer convalescent plasma significantly lowered 30-day mortality in patients not on mechanical ventilation. Data from small, randomized controlled trials, however, were inconclusive. In order to evaluate the safety and efficacy of convalescent plasma in hospitalized patients with COVID-19, researchers in the United Kingdom randomized 11,558 patients between May 28, 2020 and Jan 15, 2021 to receive either standard care plus high titer convalescent plasma (N=5795) or standard care alone (N=5763). Only 5% of patients required mechanical ventilation, and 92% received corticosteroids (considered part of standard care). Patients were randomized a median of 9 days after symptom onset. No significant differences were observed in 28-day mortality between the two groups—24% of patients in both groups died within 28 days. Median days hospitalized were similar in both groups—12 days in the convalescent plasma group and 11 days in the standard care group. Subgroup analyses did not find any unique cohorts of patients that benefited from convalescent plasma, nor did the emergence of the B.1.1.7 variant in late 2020 affect results. Current studies are evaluating whether convalescent plasma provided prior to hospitalization or for specific patient populations (e.g., immunosuppressed) may be beneficial.
References:
- RECOVERY Collaborative Group, Horby PW, Estcourt L, Peto L, Emberson JR, et al. Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomized controlled, open-label platform trial. The Lancet 2021
- Liu STH and JA Aberg. Convalescent plasma inpatients hospitalized with COVID-19. The Lancet 2021
