The White House has named longtime vaccine skeptic Jim O’Neill as acting director of the CDC, replacing Susan Monarez, who was on the job for just a few weeks. NBC News Health and Medical Reporter Erika Edwards joins host Brian Cheung to break down what this shake-up means for public health. And on the 20th anniversary of Hurricane Katrina’s landfall, Dateline anchor Lester Holt reflects on what it was like to cover the tragedy in real time for both Nightly News and the Today show.