A large, multicenter clinical trial of adults hospitalized with COVID-19 across the United States suggests that convalescent plasma may be a safe and readily available treatment option at the beginning of a pandemic wave when other therapies are not yet available.

Results of the randomized, double blinded, placebo controlled trial, co-led by Liise-anne Pirofski, M.D., and Hyunah Yoon, M.D., at Einstein and Mila Ortigoza, M.D., Ph.D., at NYU Langone, were published online on December 13 in JAMA Internal Medicine. Nearly 1,000 hospitalized adults with COVID-19 at 21 U.S. hospitals were recruited between April 17, 2020, and March 15, 2021, to receive either COVID-19 convalescent plasma (CCP) from individuals who had recovered from COVID-19 or a placebo (saline). The study population was diverse, with 40% Hispanic and 14% non-Hispanic Blacks.

Over the course of the nearly year-long study, there was no overall difference in clinical outcome between the 468 participants treated with CCP and 473 who received the placebo. However, subgroup analysis by enrollment quarter showed a benefit with CCP during the first quarter of the trial (April to June 2020), when participants received CCP with the highest neutralizing titer (i.e., highest level of functional anti-SARS-CoV-2 antibodies) and when remdesivir and corticosteroids were not yet standard of care. The results highlight CCP’s heterogeneous treatment effect as the pandemic and therapeutic landscape evolved and suggest CCP with broad spectrum antibodies against circulating SARS-CoV-2 variants could be an effective therapy for the omicron variant and other variants that may arise.

Dr. Pirofski is chief of infectious diseases in the department of medicine at Einstein and Montefiore, professor of medicine and microbiology & immunology, and holds the Selma and Dr. Jacques Mitrani Chair in Biomedical Research. Dr. Yoon is assistant professor of medicine at Einstein and an attending physician at Montefiore.