Therefore correct the immune system and the overall body systems/environments. These systems and "habitats" are designed to be "hospitable" to viruses which dwell in us in a helpfully synergistic or at worst, a neural way. But our systems, when in good working order, will not be overrun by them.
I'm not saying I endorse this view. I'm just explaining what I think they're saying. It's an old theory, one which even Pasteur was attracted to.
Smallpox and the hundreds of millions of people it killed over the course of thousands of years would like to have a word with this “view”.
Our bodies host lots of viruses and bacteria peacefully. Some viruses and bacteria cause minor discomfort which can either be over quickly or chronic. Some cause more serious ailments. Some cause death if untreated. Some kill us despite all the medical knowledge we’ve accumulated to date. Nature doesn’t do a “one size fits all” approach to anything. And nature doesn’t care about “harmony” or “balance”. Things in nature kill each other all the time. Humans have found ways to put weight on the scales in our favor so that we now - on average - live longer than we ever have.
If somebody questions how viruses can overwhelm a healthy immune system, just look at Ebola. It’s explained here: https://www.youtube.com/watch?v=sRv19gkZ4E0