Although aluminum has been experimentally demonstrated to be a neurotoxin, it is nonetheless the most commonly used vaccine adjuvant. But even after nearly a century of widespread use of aluminum adjuvants, medical science's understanding of them is still remarkably poor. There is a scarcity of data on the toxicology of aluminum adjuvants, but in spite of this, the notion that aluminum in vaccines is safe seems to be widely accepted.
But experimental research has shown that aluminum adjuvants have a potential to induce serious immunological disorders in humans. In particular, aluminum in adjuvant form carries a risk for autoimmunity, long-term brain inflammation, and associated neurological complications.
According to a study on the subject in Current Medical Chemistry:
“In our opinion, the possibility that vaccine benefits may have been overrated and the risk of potential adverse effects underestimated, has not been rigorously evaluated in the medical and scientific community.”