Audio is streamed directly from the publisher (podtrac.com) as published in their RSS feed. Play Podcasts does not host this file. Rights-holders can request removal through the copyright & takedown page.
Show Notes
Polio was a terrifying threat in the early 20th century: It often left victims paralyzed or dead. Yet two vaccines caused an immediate drop in polio cases and today they've nearly eradicated the disease. But what exactly happened? Tune in to find out.
Learn more about your ad-choices at https://www.iheartpodcastnetwork.com
See omnystudio.com/listener for privacy information.