In a feat of human achievement, vaccine developers cracked COVID-19's scientific code in less than a year, testing and developing a shot that has so far proven effective against the deadly infection.
What's proving difficult now is getting that vaccine out of manufacturing facilities and into Americans' arms.
President Trump's Operation Warp Speed placed the onus on states and localities to figure out distribution. The Biden administration wants to the federal government to take a greater role in administering 100 million vaccines in 100 days. By springtime, anyone who wants a vaccine should be able to get one, the president said Monday.
Major Garrett explores the obstacles to mass vaccination, why some states are doing better than others and whether the Biden administration's goals are achievable.