The Jews kept cleaner houses than the christains because of Kosher. They also wouldn't touch the bodies of rats they killed directly, same reason. Using tongs or sticks to move vermin protected them from the fleas that carried the plague.

So, during the Black Death, they were less affected by the bubonic plague. Of course, the christains around them, who lived by the New Testament, not the rules of the Old, decided they must be protected by being in league with the Devil. So they burned the Jews out of their homes and ran them out of town.

So, i tend to find the protections of God's laws a bit ironic. Those that follow them get protected, except from the stupidity of those that don't. And if the rules are so good, why didn't they stay in effect for the Christains? What would the Black Death have been like if Christains kept Kosher?