How is it that many around me are dealing with health issues, while I generally am healthy as the proverbial horse? In my mind that occurs because I truly believe in mind over matter, and not just because I believe, but because it makes sense from a purely logical viewpoint.
See, first of all we are said to have an immune system, that staves of many things. And then there is this thing called the placebo effect, which has been proven to be real in this reality we live in. Take those two things, and you are fairly certain to live in a world of health...
But unless you can convince others to see that truth, there will be those who do believe illness to be real and capable of harming them. And that means they will be susceptible to it.