About this episode: Thanks to vaccines, most people under a certain age have no memory of the devastation and terror caused by the poliovirus. Although widely eliminated, polio still poses a threat in certain countries around the world. Waning vaccination rates in pockets of the U.S. mean some communities are at risk of a resurgence. In this episode: a look back at polio before vaccines, and how technology has evolved—including a discussion about a previous version of the vaccine that did, in rare instances, actually cause paralytic polio. Guest: is the executive director of the at the Johns Hopkins Bloomberg School of Public Health. Host: Lindsay Smith Rogers, MA, is the producer of the , an editor for , and the director of content strategy for the Johns Hopkins Bloomberg School of Public Health. Show links and related content: —The New York Times —Johns Hopkins Bloomberg School of Public Health Contact us: Have a question about something you heard? Looking for a transcript? Want to suggest a topic or guest? Contact us or . Follow us: Here's our