As the Biden administration pushes to administer 100 million vaccines within the President's first 100 days in office, mass vaccination sites are opening up. Adrienne Broaddus is live at a mass vaccination center in Chicago.

In just over a year, Covid-19 has claimed more than half a million US lives. That's more than the number of Americans killed in World War II. The victims span every age group and corner of the country. And each left an indelible legacy. CNN's Dr. Sanjay Gupta reports.