Why were there no Leave It To Beaver Christmas episodes?

The TV show "Leave It To Beaver" was about an ordinary suburban American family in the 1950's, the Cleaver family, and particularly their son nicknamed Beaver, and the various adventures that befell him in the course of his life. Viewed from the perspective of the 21st century, the impression given by this show is primarily one of immense naivety. How petty their concerns were, and how blind to the huge global problems which were brewing in the 1950's, which would in various ways blow up in the 1960's and onwards.