Hallberg's Picture of Health: How'd the vampire myth start?

A still from 'Nosferatu'
The vampire Count Orlok from the 1922 film "Nosferatu" is destroyed by sunlight.
Hulton Archive | Getty Images

Odds are that a fair number of kids who'll stop by your door on Halloween will be dressed as vampires.

There's no evidence that vampires ever existed. But over the years, we've always been eager for a scientific explanation for it.

Dr. Jon Hallberg joined All Things Considered host Tom Crann to talk about what could be behind the vampire myth.

Use the audio player above to hear their conversation.