Covid-19 patients who were treated with donor plasma – hyperimmune plasma – who have overcome Covid-19 infection are less likely to need oxygen assistance 14 days after admission and, according to a study published in « Nature Medicine ‘, were more likely to survive than those who did not receive plasma.
Conducted in New York, this retrospective case-control study of 39 patients hospitalized with severe symptoms suggests that hyperimmune plasma may be potentially effective against COVID-19, although more studies are needed.
Therapy with plasma from donors who have overcome Covid-19 infection is considered a provisional treatment waiting for new antiviral drugs and vaccines. Plasma donated by people who have recovered from COVID-19 is the component of blood that contains antibodies, including those that specifically recognize SARS-CoV-2. These antibodies, transfused into patients infected with SARS-CoV-2, are believed to induce an antiviral effect by suppressing the viral infection, complementing the patient’s own immune responses. However, protection against covid-19 has not yet been directly related to circulating antibody levels against SARS-CoV-2.
Nicole Bouvier and her team at Mount Sinai Hospital in New York City selected 39 patients admitted to their center between March 24 and April 8, 2020, to receive a hyperimmune plasma transfusion.
Two-thirds of the patients were men and one-third women, with a mean age of 55 years. The patients tended to be obese, but overall they had a few other pre-existing conditions. On the day of the transfusion, 87% of patients required supplemental oxygen through a non-invasive device, and 10% required assisted ventilation.
The control group consisted of COVID-19 patients admitted for the same period of time with a history of infection, symptoms, and pre-existing conditions similar to those in the treatment group.
Fourteen days after the transfusion, 18% of the treatment group required more oxygen, while this figure was 28% in the control group. At the end of the study on May 1, 13% of the patients in the treatment group and 24% of the control group had died, and 72% and 67% had been discharged alive, respectively.
The authors conclude that this study provides evidence that hyperimmune plasma transfusion can be an effective treatment for covid-19, but a larger number of patients and randomized trials are needed to definitively determine the efficacy of this therapy.