Severe acute respiratory syndrome coronavirus 2
In one study, doctors gave a drug called remdesivir to 61 COVID-19 patients on a compassionate basis, meaning they gave them the drug because there was no other treatment available.  Scientists studied 53 of these patients and found that 68% of the patients got better, 13% died, and 25% had serious side effects.  But because the study had no control group, meaning these patients were not compared to other COVID-19 patients who were not taking remdesivir, and because only 53 people were in the experiment, scientists must run more studies before they can be sure remdesivir works.