Ahhh modern medicine. Where we try something random that has all sorts of effects on our body. One of those effects just happens to be something we may be looking for, the rest we call "side effects". Nope, they are all effects. Also, if we happen to add them all up; there are way more 'negative' effects than there are 'positive' ones.
Also, may be fun to point out, everything we're vaccinating ourselves from only exists because of our disconnection with a natural diet and way of life...
:)