President Joe Biden provided a new May timeline for coronavirus vaccinations this week with officials saying the process of administering vaccines to all Americans will likely go into the summer. The timeline depends on the government's ability to deliver the doses, as well as Americans' willingness to get the shots. The improved outlook comes as the President announced a partnership between Merck and Johnson and Johnson to make the single-dose vaccine. To discuss, we were joined by Dr. William Schaffner, Professor of Infectious Diseases at Vanderbilt Medical Center.