A few weeks after the new coronavirus arrived on U.S. shores, Dr. Arturo Casadevall hatched a plan to beat back the outbreak with a medical advance so powerful it had earned a Nobel Prize.
That’s when Dr. Emil Adolf von Behring was honored for pioneering the use of so-called convalescent serum as a treatment for diphtheria. In 1892, the Prussian bacteriologist infected horses with the pathogen that causes the deadly disease. If the beasts recovered, Von Behring harvested their blood, removed its red blood cells and clotting proteins, and introduced the resulting antibody-rich fluid into the bloodstreams of human diphtheria patients.
Until a diphtheria vaccine came into broad use in the 1930s, Von Behring’s daring