Boston is on lock-down this morning as police continue to hunt for the 2nd suspect in the Boston marathon bombings. Overnight, the two suspects killed an MIT police officer, injured a transit officer in a firefight and threw explosive devices at police during their getaway attempt. One suspect was killed, the surviving Boston bombing suspect has been identified as Dzhokhar A. Tsarnaev, 19, of Cambridge, Mass.

Scientists have firmly established that childhood vaccines do not cause autism, but many people still choose not to vaccinate their kids. Writer Seth Mnookin talks to Brooke about why vaccinations are still down, two years after an investigation that completely discredited the anti-vaccine movement's strongest study. 

Seth Mnookin, contributor to New York Magazine, a former senior writer for Newsweek where he covered media, politics, and popular culture, and the author of The Panic Virus: A True Story of Medicine, Science, and Fear, looks at how The New York Times became "the last great paper standing," as discussed in this week's New York Magazine cover story.

Seth Mnookin is a contributing editor at Vanity Fair and a former senior writer for Newsweek, where he covered media, politics, and popular culture. His new book, The Panic Virus: A True Story of Medicine, Science, and Fear, looks at the way science and popular culture have diverged on the issue of childhood vaccinations and the risk of autism.