One of the biggest concepts of quantum physics is that "everything is energy." So, whether an object/ person/ animal is animate or inanimate, we emit a certain frequency (which relates intrinsically to our health), and although unseen, this frequency is nevertheless palpable.
Some people might refer to this frequency as the 'aura', or 'light body' or 'energy field' that surrounds our physical body. In truth, our frequency doesn't just surround us, we are it...
Another very important concept to grasp, is that this frequency is not fixed: it can change. So we can learn to emit another signal should we wish to, and this will in turn change our physical body.
In short, our bodies reflect our frequency or vibrancy, not the other way around. So our inner/ internal environment is of paramount importance.
Basically you can think of ill health - or dis-ease - as emitting a lower frequency, and good health as emitting a higher frequency. It is more complex than that, but for now that's a good place to start.
So, you may wish to question 'The Germ Theory' (Louis Pasteur) as we know it, and focus more on 'The Terrain Theory' (Antoine Bechamp) when it comes to understanding how pathogens can be 'caught' ... or not... The Terrain Theory of course focuses largely on the premise that our inner environment determines how likely we are to 'catch' a virus or bacteria for example.
Even Louis Pasteur, on his deathbed, was supposed to have admitted that his Germ Theory wasn't accurate. So why the need for vaccines of any type you might well ask?