To date, the total number of reported patients treated with HCQ, with or without zinc and the widely used antibiotic azithromycin, is 2,333, writes AAPS, in observational data from China, France, South Korea, Algeria, and the U.S.

Of these, 2,137 or 91.6 percent improved clinically.

There were 63 deaths, all but 11 in a single retrospective report from the Veterans Administration where the patients were severely ill.

The antiviral properties of these drugs have been studied since 2003. Particularly when combined with zinc, they hinder viral entry into cells and inhibit replication. They may also prevent overreaction by the immune system, which causes the cytokine storm responsible for much of the damage in severe cases, explains AAPS. HCQ is often very helpful in treating autoimmune diseases such as lupus and rheumatoid arthritis.

Additional benefits shown in some studies, AAPS states, is to decrease the number of days when a patient is contagious, reduce the need for ventilators, and shorten the time to clinical recovery.