This is because the MLM/anti-vaccine market penetration into healthcare professionals (nurses especially) is unfortunately really high. As it turns out, not even a lifetime of training and knowledge can prevent being suckered by grifters.
Somehow you can make the same answer without denigration.
I don't believe in "anti-vaccine market penetration".
My model I use is that ALL people are ignorant of most things that happen around them and only SOME people are knowledgeable about SOME of the things.