New York: In an ongoing study of more than 300 Covid-19 patients treated with convalescent plasma therapy in the US, researchers suggest that the treatment is safe and effective.
The study, published in the American Journal of Pathology, tracked 350 severely ill Covid-19 patients admitted to the Houston Methodist's system of eight hospitals from March 28 through July 6.
"Our studies to date show the treatment is safe and, in a promising number of patients, effective," said study author James M Musser from the Houston Methodist in the US.
"While convalescent plasma therapy remains experimental and we have more research to do and data to collect, we now have more evidence than ever that this century-old plasma therapy has merit, is safe and can help reduce the death rate from this virus," Musser added.
The research team found that those treated early in their illness with donated plasma that has the highest concentration of anti-Covid-19 antibodies are more likely to survive and recover than similar patients who were not treated with convalescent plasma.
Patients with a history of severe reactions to blood transfusions, those with underlying uncompensated and untreatable end-stage disease and patients with fluid overload or other conditions that would increase the risk of plasma transfusion were excluded.
According to the study, the patients were tracked for 28 days after plasma transfusion and were compared to a control group of similar Covid-19 patients who did not receive convalescent plasma.
An observational propensity score-matched analysis was used to balance the characteristics of participants and allow for an objective interpretation of the results at this stage, the researchers said.
"These latest results offer valuable scientific evidence that transfusing critically ill Covid-19 patients with high antibody plasma early in their illness -- within 72 hours after hospitalisation proving most effective -- reduced the mortality rate," the author wrote.
Several studies have measured safety, showing that the more than 34,000 Covid-19 patients in the US who have received plasma transfusions for Covid-19 experienced minimal adverse effects.