Using plasma transfusions to treat COVID-19

Convalescent plasma – using a transfusion of blood with antibodies donated by recovered patients – may just be a stop-gap measure against COVID-19 until more treatments and a vaccine come along. But doctors have already used donated plasma on thousands of patients, and are finding some success with a procedure that dates back more than 120 years in the fight against the spread of disease. Allison Aubrey, of National Public Radio, reports.