In the Washington Post’s “Wonkblog,” columnist Ezra Klein interviews Bill Gates, co-chair of the Bill & Melinda Gates Foundation, about his focus on improving global health and efforts to eradicate polio. According to the interview transcript, Gates discusses challenges in public health data collection, replicating successful health programs in different settings, the logistics involved in immunizing all children against polio, and the costs associated with some health care innovations (5/17).