How will we know when the pandemic's beaten back?

Vaccination levels are rising across the country, and hopefully some of the hesitancy that we've been hearing about is being beaten back. We wanted to check in with Dr. Atul Grover, Executive Director of the Association of American Medical Colleges Research and Action Institute to ask about the questions he's getting about the vaccine, how we're doing at getting shots in arms, and a new question that we get to start spending some energy on now: how will we know when we've won?