Known as convalescent plasma therapy, the treatment harks back to the late 19th century, and doctors today are suggesting it may be the stop-gap we need to hold the virus at bay while more complex treatments and vaccines are developed.

A very special juice

In the 1890s German scientist Emil Behring pioneered a novel treatment for diphtheria. Behring, along with a Japanese physician named Kitasato Shibasabur?, discovered that blood serum from animals infected with certain toxins could be infused into humans providing treatments for various illnesses.

Behring described these protective molecules at the time as "antitoxins," and spent the rest of the decade optimizing the process. He ultimately found horses to be the most efficient animal for producing large volumes of serum antitoxins.