God designed the perfect 'inoculation schedule' for humans ... besides breast milk and sunshine babies are meant to crawl around on the ground put dirt, rocks and bugs in their mouths .. get all slobbered on by the dog, and the cat, play w/ the chickens and other animals.
As long as we aren't spreading poison all around on our yards, farms and animals they ALL contribute to the slooooow NATURAL development of general healthy immune systems.