How Blood From Covid-19 Survivors Might Save Lives

A century-old approach for fighting infections offers hope as people wait for drugs and vaccines to thwart the novel coronavirus disease

- Paola Navarette

As cases continue to spike globally, scientists are showing renewed interest in a treatment with ancient roots and many modern applications: convalescent plasma therapy. If it works, the blood of COVID-19 survivors would be used to protect frontliners and prevent patients from getting seriously ill.

The therapy is based on a medical concept called ‘passive immunity.’ Blood from people who have recovered from an infection can be a rich source of antibodies, proteins made by the immune system to attack a pathogen. Infusions of plasma—the clear liquid that remains when blood cells are removed—may increase the patients’ disease-fighting response to a virus, giving their immune systems an important boost. This approach has been used for decades to treat infectious diseases such as Ebola, the Spanish flu, rabies, polio, and SARS.

Preliminary data on a handful of patients in China showed they got better after receiving plasma infusion from survivors, but large-scale clinical trials must be done to prove its effectiveness.

In the study, a 200 ml dose of convalescent plasma was administered to 10 adult COVID-19 patients with severe symptoms. The patients witnessed significant improvement on their clinical symptoms, and the viral load was undetectable in seven patients who had previous viremia. No severe adverse effects were also observed.