Three years. That's how long it's been since we first became aware of the threat of COVID-19.  During her recent teleconference, we asked the head of the Roanoke City Alleghany Health District to reflect on this anniversary that is both somber and celebratory. Dr. Cynthia Morrow says there is so much we've learned from COVID-19. And while it's hard to extract silver linings from tragedy, there is a lot public health leaders are grateful for.