Mercury and aluminum injected into children repeatedly ain't too grand, but there's also an immunogenic brain damage component. Look up microglial priming by Blaylock in particular. There are a number of mechanisms.

Hepatitis B vaccine induced brain dysfunction.
https://www.ncbi.nlm.nih.gov/pubmed/27501128
https://www.ncbi.nlm.nih.gov/pubmed/29751176

You have the well reported alteration of antigen presentation in the gut, massive inflammation. That's against a background of other environmental factors which destroy proper gut flora.

Section 13 of every vaccine insert, as its sole content, contains a variant of the following:
"[Vaccine] has not been tested for mutagenic potential, carcinogenic potential, or impairment of fertility."
Look up immunocastration. A variant of this was tested on girls in Kenya.

Inserts are here:
https://www.fda.gov/vaccines-blood-biologics/vaccines/vaccines-licensed-use-united-states

Purported vaccine content is here:
https://www.cdc.gov/vaccines/pubs/pinkbook/downloads/appendices/B/excipient-table-2.pdf

Notably some independent testing found various "contaminants" in human vaccines, but not veterinary.

Historical data on disease rates indicates vaccines are introduced only after other measures have reduced rates of disease. Actual treatments and prevention have been suppressed in favor of vaccination, simply things like vitamin C and vitamin A for measles. Polio was successfully treated and aprtially reversed in its flaccid paralysis staged with injections of sodium ascorbate and iirc a small amount of copper salicylate. Polio itself only became an issue after other vaccines, indicating immune disruption and inability to handle organochloride pesticide bombardment, diethylstilbestrol, etc.

Vaccination is a house of cards. You may not realize it yet, but the great role of our generation is to destroy this evil.