The Alzheimer's narrative seems to partially be its own theory but also bolsters the villainization of Dr Anthony Fauci. While claims of deaths from the vaccines were dispelled much more easily, conspiracy beliefs and rumors that purport serious side effects that would take years to appear would take at least that long to disprove.
It’s an unfortunate reality because one need not supply evidence to make such a claim. The bar for science remains high while the bar for casting doubt does not exist. The field is asymmetrical, so strategic consideration should be given to mis/mal/disinformation that has the potential to pose a longer term issue like claims that vaccines cause dementia, cancer, or infertility.
Anonymous claims and personal stories, whether vaccines are the cause of the disease or not, will continue to drive anti-vaccine sentiments. Data lacks the compelling quality found in narratives, and with a guaranteed firehose of compelling stories in the future because of vaccination on a never before seen scale, disinformation and misinformation researchers must look to the future, too. The rumors of today do require our attention, but disinformation seeds being planted now will mature and produce potent conspiracy beliefs and false claims.
With billions ultimately receiving this vaccine when all is said and done, there will be people who develop dementia who would have anyhow. People who hear vaccine misinformation may see in this, proof of claims. Any common disease might then be fodder for new misinformation.
Although it will be possible to show that vaccines did not cause the dementia—of course assuming the vaccines did not cause dementia because if they did the evidence would show that—science must face the reality that the evidence to show this essentially already exists.
It exists and it was ineffective at preventing these ideas from spreading and stoking hesitancy. Whatever is lacking right now, it’s not the evidence.