Early administration of convalescent plasma from people who have recovered from SARS-CoV-2 to infected older adults reduces the progression of Covid-19. This is suggested by a small clinical trial, one of the first to conclusively point out the beneficial effects of this treatment.
The results, published on Wednesday in the magazine « The New England Journal of Medicine»Are among the first to point out so conclusive towards the beneficial effects of treatment, often discussed.
Thousands of patients have received plasma infusions in the months since, while researchers awaited the data. The new study is one of the first well-designed clinical trials to show that the therapy has any benefit.
Plasma therapy from donors who have overcome Covid-19 infection is considered an interim treatment pending 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 levels of circulating antibodies against SARS-CoV-2.
Last summer, the US Food and Drug Administration. (FDA), under pressure from the president Trump, greenlit the therapy for use in people hospitalized with Covid-19 in the U.S. However, at the time of emergency clearance, there was little evidence.
The new study, led by Fernando Polack, and scientific director of the INFANT Foundation in Argentina, seems to clarify the circumstances in which plasma has its advantages.
«Plasma is just an antibody-carrying vehicle. 28% of people have, according to our study, the amount of antibodies necessary to donate plasma for this treatment. By restricting donors to those with higher antibody concentrations, it is possible to further improve plasma yield. Although this leaves a group of convalescents out of the donation, between 4 and 8 recovered patients have the necessary antibodies to be a donor. Patients who had pneumonia or needed hospitalization tend to produce the most antibodies, ”explains Polack.
In their study of 80 people, an infusion of plasma reduced the risk of developing a severe case of Covid by 48%, compared to another group of 80 who received a saline solution.
The key aspect of these results is patient selection and early administration: all of the people enrolled in the trial were at least 65 years old, the group at greatest risk of becoming seriously ill. About half of the participants also had health problems that made them more vulnerable to the virus.
And plasma therapy, which was evaluated to ensure it contained high levels of antibodies, was always given within three days of the onset of symptoms.
“This study describes the first strategy in the world to stop the progression of SARS-COV2 with an inexpensive, universal, non-patent, proven safe intervention that can be administered on an outpatient basis in care units without the need for hospitalization,” he says. the investigator.
“Giving therapy too late has no effect,” the study concludes.