There are more than 170 vaccine candidates for the novel coronavirus being developed and tested around the globe. A handful are in phase 3 trials, large scale testing on tens of thousands of people to determine safety and efficacy. We start this hour catching up on where the vaccines stand, the plans to distribute them and how politics are complicating it all with New York Times science writer CARL ZIMMER. Then, there’s been a lot of debate about whether kids can safely return to school but many kids have been back for a few weeks now. So what are we learning about infections and spread in class? Brown University economist EMILY OSTER is tracking Covid cases in schools to find out and shares what she’s found.