Thousands could have been saved during the pandemic with expanded use of convalescent plasma

A new study led by researchers at Johns Hopkins Bloomberg School of Public Health estimates that thousands of lives could have been saved during the first year of the COVID-19 pandemic if convalescent plasma had been used more broadly, particularly in outpatients at high risk for severe disease and in hospitalized patients during their first few days of admission.

Convalescent plasma from patients who had recovered from COVID was used starting in the early months of the pandemic at the urging of a group of physicians who cited the blood byproduct's success as a therapy in earlier infectious disease emergencies, including the global influenza pandemic of 1918–1920, and the SARS epidemic of 2002–2004. Plasma from patients recently recovered from a pathogenic infection, such as COVID, typically contains antibodies that may block or reduce the severity of the infection in others.

A total of 647,795 units of plasma was given to inpatients with COVID between July 2020 and March 2021. The team used this as a measure of the number of patients treated.

Arturo Casadevall, MD, PhD, study senior author, Bloomberg Distinguished Professor of Molecular Microbiology and Immunology and Infectious Diseases, Bloomberg SchoolThis is a therapy that can reduce mortality, be immediately available, and is relatively inexpensive-;we should be prepared to use it much more in a future infectious disease emergency or pandemic."

Casadevall was one of the earliest proponents of convalescent plasma at the start of the pandemic. The study's first author is Quigly Dragotakes, PhD, a postdoctoral fellow in the Casadevall laboratory.

• If 15% of outpatients had received convalescent plasma, the authors estimate that between 85,268 and 227,377 hospitalizations would have been avoided. 
• If 75% of outpatients received convalescent plasma, between 426,331 and 1,136,880 hospitalizations would have been avoided. 

During the first year of the pandemic, convalescent plasma was approved only for use in patients hospitalized with COVID.

Initial studies of the effectiveness of convalescent plasma in the U.S. and other countries had mixed results. Casadevall and colleagues note this was due in part to the challenges of ensuring that convalescent plasma contained sufficiently high anti-SARS-CoV-2 antibody concentrations. Another issue with many early studies, the researchers say, was that convalescent plasma was given to patients hospitalized with COVID already too sick to benefit much from the therapy.

The researchers note that use of convalescent plasma during the pandemic was safe and its cost-;averaging about $750 per unit in the U.S.-;is lower than newer, patented COVID treatments.

The authors recommend that public health preparedness planning for future infectious disease outbreaks, epidemics, and pandemics include readiness to collect and deliver convalescent plasma at scale.

"We should be ready to set up outpatient centers to treat people early on with convalescent plasma during a future outbreak," Casadevall says. "It would require designating spaces in hospitals for that purpose, but we wouldn't need any new technology-;this is well-established medical knowledge and practice."

Source:

Johns Hopkins Bloomberg School of Public Health

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