That's what we've always believed, at any rate.
4 seconds sound clip from the The Last Man on Earth (1964) movie soundboard.
You can hear this line at 00:36:33 in the Blu-ray version of the movie.
Quote context
[...]
- And you don't believe some of the dead have come back?
- And why are they burning the bodies? Why don't they bury them?
- Because it's the best known way to control the contagion... to keep the germ from spreading.
- That's what we've always believed, at any rate.
- You'd prefer us to believe in vampires?
- There are stories being told. By people who are out of their minds with fear!
- Maybe, but there are too many to be just coincidental.
- Stories about people who have died, and have come back.
[...]