Administration of convalescent plasma reduces the need for hospitalization in symptomatic Covid-19 patients, according to findings of a multicenter study published in the New England Journal of Medicine.¹

 The efficacy and safety of Covid-19 convalescent plasma in preventing Covid-related hospitalization was investigated in the Convalescent Plasma to Limit SARS-CoV-2 Associated Complications (CSSC-004) Study. For this, researchers recruited 1181 symptomatic Covid-positive patients, aged ≥18 years, within 8 days of symptom onset from June 3, 2020, through October 1, 2021. Most of them were unvaccinated. The study participants were administered either high-titer convalescent plasma or placebo control plasma without SARS-CoV-2 antibodies 1 day after randomization. Hospitalization due to Covid-19 within 28 days post-transfusion was taken as the primary end point.

Results showed that 17 of 592 participants (~3%) who received convalescent plasma transfusion needed to be hospitalized within 28 days of the transfusion compared to 37 patients out of 589 participants (6.3%) in the control group with a relative risk reduction of 54%.

This randomized trial has shown that early outpatient administration of convalescent plasma effectively reduced the requirement of hospitalization in more than half of the study population, many of whom were unvaccinated. Convalescent plasma is relatively inexpensive. The authors suggest that plasma containing high titers of SARS-CoV-2 antibodies may be kept available at blood banks, particularly in resource-limited settings, for patients in the early stages of the infection when monoclonal antibodies are not easily accessible or available.

The US FDA has limited the authorization of COVID-19 convalescent plasma “only for the treatment of hospitalized patients with COVID-19 early in the disease course and to those hospitalized patients who have impaired humoral immunity and cannot produce an adequate antibody response”. But, the Health Ministry’s guidelines for management of adult Covid-19 patients, revised in January this year, do not mention convalescent plasma as a therapeutic option.

Reference

1. Sullivan DJ, et al. Early outpatient treatment for covid-19 with convalescent plasma. N Engl J Med. 2022 Mar 30. doi: 10.1056/NEJMoa2119657.