There are indeed many examples of this, especially in third-world countries ruled by dictators or superstitions, or a combination of the two. But that doesn't

There are indeed many examples of this, especially in third-world countries ruled by dictators or superstitions, or a combination of the two. But that doesn't stop us from creating those cures/preventions for ourselves, because it's still the right thing to do. We may eventually get through to them, at any rate. See Bill Gates and Polio vaccines, for example.