John Mellors, M.D., chief of infectious diseases, UPMC and the University of Pittsburgh, discusses a scientific breakthrough that is a major step toward a potential drug to treat and prevent COVID-19.Credit: UPMC AnimalAntibodyCOMPONENTCoronavirusCOVID-19COVID19drugeffectiveHIGHLYimmune systemIMMUNITYsarscov2studiesTinyvideoVITAMINvitamin covid19vlogYouTube