Re: Can someone explain...
"If you are around animals a lot (farm kid etc) then you don't need MMR, just the measles jab. In fact, many of our "industrial" diseases are because we stopped living around animals."
Cowpox exposure may have helped reduced the seriousness of Smallpox, but was not itself trivial. People did die of it.
Jenner's ideas let people have the benefit of cowpox without the infection being serious.
With regard to other conditions like Rubella, Mumps and Measles, I have yet to hear of that, so would appreciate being pointed to corroborated, peer-reviewed information.
Sounds more like a confusion of history and myths here.