Small study shows convalescent plasma reduces risk of severe Covid-19

Convalescent plasma from patients who have already recovered from Covid-19 can help many older patients suffer a severe illness, a clinical study showed.

The results of a small clinical trial published in the New England Journal of Medicine on Wednesday showed that the risk of severe Covid-19 was reduced by 48% among the 80 patients administered with plasma, when compared with a control group that was given a placebo.

Nevertheless, the antibodies contained in the plasma, which help to protect against Covid-19, have not yet been shown to offer protection against SARS-CoV-2, the virus that triggers Covid-19.

The study was conducted by Fernando Polack at Argentina's INFANT foundation.

All of the study's participants were at least 65 years of age and were therefore at a higher risk of suffering severe forms of Covid-19.

Furthermore, roughly half of the volunteers in the trial suffered from so-called comorbidities or factors that made them more vulnerable.

In the case of all patients administered with plasma, it was given within three days following the onset of symptoms. Treatment with plasma proved ineffective when administered after more than three days from infection.

The study also showed that roughly 28% of people who had recovered from Covid-19 had levels of antibodies high enough for their plasma to be given to others as treatment.