Convalescent plasma treatments have little effect on severe Covid-19 patients, research results have shown.   

A group of researchers in Argentina released a research paper, “A Randomized Trial of Convalescent Plasma in Covid-19 Severe Pneumonia,” in the New England Journal of Medicine (NEJM) on Tuesday. 

The team obtained permission from 333 severe Covid-19 patients to test out two different therapies. They randomly assigned 228 patients with plasma and 105 patients with placebo. The subjects’ average age was 62. After observing the two groups for 30 days, they found no clear difference based on a six-point clinical scale ranging from total recovery to death. 

Of the 228 people in the recovery period, 25, or 11 percent, died within 30 days, while 12 out of 105 people in the placebo group died, showing the mortality of 11.4 percent.

The hospitalization rate of intensive-care units and the use of respirators were also similar for both groups. In the convalescent plasma group, 53.9 percent were hospitalized in intensive-care units, and 26.8 percent used respirators. In comparison, 60 percent of the placebo group used intensive-care units, and 22.9 percent used respirators.  

Antibody titer showed a higher rate in the convalescent plasma group on the second day. However, there were similar adverse reactions in both groups, the team said. 

Convalescent plasma treatment has been used for more than a century, hoping that it can speed up the immunization process for patients, the Argentine researchers said. Despite the great interest in administering the therapy to fight Covid-19, clinical tests showed insignificant differences, they noted.

“As the results show, we concluded there is no huge difference in clinical conditions or overall mortality rates between patients that received convalescent plasma and those that received a placebo treatment,” a researcher from the team said. “The use of plasma therapy should be reevaluated as a standard treatment.”