With each day since U.S. President Donald Trump reported that he tested positive for COVID-19, his doctors have added a new major therapy to treat the disease, for a total of three at this point.

On Friday—the same day that Trump said he tested positive—the President received an experimental combination of two monoclonal antibodies to help his immune system fight the coronavirus infection, according to his physician, Sean Conley. The next day—after he was hospitalized at Walter Reed National Military Medical Center—he received the drug remdesivir, which blocks the coronavirus’s ability to make more copies of itself. Remdesivir is not approved by the U.S. Food and Drug Administration, but has received emergency use authorization for treating COVID-19. …