My guess is that this piece of disinformation originates from one of the numerous anti-vax propaganda sites?
An MTHFR gene mutation affects metabolism of folate. That is all. While that does affect health, it has absolutely no relation to the ability of the body to metabolize the proteins that are contained in vaccines. Proteins are derived from pathogens and are the vaccine component that induce immunity. They induce immunity because the body perceives them the same way it perceives microorganisms, and reacts the same way. But, unlike microorganisms, the proteins have no ability to cause disease since they are not alive and do not grow. The body digests those proteins the same way it digests proteins derived from food.
“My guess is that this piece of disinformation originates from one of the numerous anti-vax propaganda sites?”
Some children are unable to deal with live viruses and some are unable to detoxify the metals (mercury & aluminum adjuvants) coming from vaccines and other sources. I haven’t been too deeply involved in the issue for several years, but the Hannah Poling case and subsequent vaccine injury compensation (for autism) involved one of the two. I’ve forgotten which one it was.
At minimum, every child who is to be vaccinated should be tested for these two conditions, prior to vaccination. It would be the ethical thing to do.