Blood plasma taken from coronavirus survivors and infused into hospitalized patients reduced their mortality rate by about 57%, a team of researchers reported Thursday.
“These results favor the efficacy of convalescent plasma as a COVID-19 therapeutic agent,” wrote the researchers, who are working with US federal government support to study plasma for coronavirus patients.
Century-old method: The team looked at all the studies they could find on the approach, which has been used in epidemics for at least 100 years. The idea is that blood from disease survivors is loaded with antibodies and other immune system compounds that can kick-start an immune response to a fresh infection. It’s a relatively cheap and low-tech approach.
They came up with studies covering more than 800 coronavirus patients around the world, including three randomized controlled trials, which are considered the strongest type of study because they involve randomly assigning patients to one treatment or another for a fair comparison.
“All studies included patients with severe or life-threatening COVID-19,” the team wrote in their report published on the pre-print server MedRxiv, which has not been peer-reviewed.
What are the findings: The researchers found patients transfused with convalescent plasma exhibiting a lower mortality rate. About 13% of patients who got plasma died, compared to 25% of those who did not get the infusions. That’s a 57% reduction in mortality.
“Given the safety of plasma administration in COVID-19 patients, the results of this real-time data aggregation provide encouragement for its continued use as a therapy and may have broad implications for the treatment of COVID-19,” said the team, led by the Mayo Clinic’s Dr. Michael Joyner.
“Importantly, many of the patients enrolled in the studies included in the present analyses received convalescent plasma transfusions later in their disease course,” they added. Earlier treatment could reduce mortality further, they speculated.