Cambridge Health Alliance (CHA), an academic community health system serving Cambridge, Somerville and Boston's metro-north region, has launched its first-ever clinical drug trial (ClinicalTrials.gov #NCT04419025). The study explores whether N-acetylcysteine (NAC), a drug commonly used to treat acetaminophen (Tylenol) poisoning and to prevent exacerbations of COPD (emphysema), can prevent mild to moderate COVID-19 symptoms in patients from progressing to severe disease.