As family and friends contemplate how to spend Thanksgiving together this year in the midst of the coronavirus pandemic, Dr. William Schaffner joins "CBS This Morning" national correspondent Jericka Duncan to offer advice on minimizing the virus of catching and spreading the virus. Dr. Schaffner, a professor of preventive medicine and infectious disease at Vanderbilt University also explains how there's a light at the end of the tunnel with the vaccines currently in development.