It has nothing to do with being charmed. These infections are generally rare to start with, and are not automatically life threatening.

There's a reason humans survived to modern day.

> There's a reason humans survived to modern day.

well we made a bunch of kids to offset deaths.

I mean, sure, getting chicken pox was relatively common when I was a kid, and few people died of it. But a low percentage of all the population is still a large number of people.