For us, we are Christian, and part of our beliefs are that God made us in His imagine, just the way that He intended us to be. He gave us what He wanted us to have; if He wanted us to have these automatic abilities to be immune to disease, then we'd be born with such.
We are born with it ..it's called your immune system, but with all of the crap in the world today, our immune systems need help sometimes. Especially those who are unfortunate enough to have weak immunbe systems. I am a Christian also , and I beleive in God, but God also saw the importance of Doctors to help us. He has answered many prayers through the working of others, Doctors, Nurses etc.
In a similar context, a child born with a defective heart. This may be the way God intended, But should we just not do anything and let the child die or should we use the toos avaliable to us to cure the child?
Some of us go to the grave with our music still in us!!!