Convalescent Plasma Can Be Effective for COVID-19 if Given Early

April 1, 2022

Convalescent plasma is an effective and safe option as an early outpatient coronavirus disease 2019 (COVI-19) treatment, according to a study published in The New England Journal of Medicine.

The research showed that high-titre convalescent plasma, when administered to outpatients within 9 days after testing positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), reduced the need for hospitalisation for more than half of the study’s predominantly unvaccinated outpatients.

“Based on our findings and conclusions, which are now validated through the peer-review process, we encourage healthcare professionals to keep SARS-CoV-2 antibody-rich blood plasma available in their blood banks as part of the treatment arsenal against early-stage COVID-19,” said David Sullivan, MD, Johns Hopkins University School of Medicine, Baltimore, Maryland. “We believe that the best role for convalescent plasma is extending its use to early outpatient treatment when other therapies, such as monoclonal antibodies or drugs, are either not readily available -- as in low- and middle-income countries -- or ineffective, as with SARS-CoV-2 variants that are resistant to certain monoclonal antibodies.”

The study included 1,181 patients aged 18 years and older who had tested positive for SARS-CoV-2, regardless of their risk factors for disease progression or vaccination status. Participants were enrolled within 8 days after symptom onset and received a transfusion within 1 day after randomisation. Participants were enrolled from June 3, 2020, through October 1, 2021.

In the prespecified modified intention-to-treat analysis that included only participants who received a transfusion, the primary outcome of COVID-19-related hospitalisation within 28 days after transfusion occurred in 17 of 592 (2.9%) patients who received convalescent plasma and 37 of 589 (6.3%) patients who received control plasma (P = .005), which corresponded to a relative risk reduction of 54%.

Evidence of efficacy in vaccinated participants cannot be inferred from these data because 53 of the 54 participants with COVID-19 who were hospitalised were unvaccinated and 1 participant was partially vaccinated.

A total of 16 grade 3/4 adverse events (7 in the convalescent-plasma group and 9 in the control-plasma group) occurred in participants who were not hospitalised.

“Based on the findings of an analysis in the new paper that wasn’t available when the preprint was posted, we found that if convalescent plasma is given within 5 days after diagnosis, the effectiveness at reducing hospitalisation approximated 80%,” said Dr. Sullivan.

“We concluded that these results strongly support high-titre SARS-CoV-2 convalescent plasma as an effective early treatment for COVID-19 with advantages such as low cost, wide availability, and rapid resilience to the virus’s evolving variants,” added coauthor Kelly Gebo, MD, Johns Hopkins University School of Medicine.

Reference: https://www.nejm.org/doi/full/10.1056/NEJMoa2119657

SOURCE: Johns Hopkins Medicine