To clarify when I mention impact on brain, I mostly mean brain fog and neurological symptoms. Here are some, I would have to keep a list somewhere to provide this though.
And vaccines either don't reduce the danger of covid affecting your brain at all or it reduces it by some unknown factor
The issue with your citations is that they analyze breakthrough infections, not exposures. You're correct in that vaccines may not protect an infected individual from neurological damage to the same degree they do lung damage, but you seem to be overlooking all the infections that don't happen at all because of the vaccine. In those cases the vaccine was effective in preventing brain damage due to covid.
Yes, agree with that, but I thought this to be an entirely different topic and a given. I should probably point this out as a disclaimer still. All of what I said was for the case after you've got covid not accounting for your vaccination status or behaviour at all necessarily.
The main point is that even with the vaccine you should still be careful about getting covid since it may not necessarily fully protect against long covid, which for me is a much bigger danger than say chance of hospitalisation or death.
Risk factors and disease profile of post-vaccination SARS-CoV-2 infection in UK users of the COVID Symptom Study app: a prospective, community-based, nested, case-control study https://www.thelancet.com/journals/laninf/article/PIIS1473-3...
Six-month sequelae of post-vaccination SARS-CoV-2 infection: a retrospective cohort study of 10,024 breakthrough infections https://www.medrxiv.org/content/10.1101/2021.10.26.21265508v...
Anecdotal reports for covid or vaccine long term symptoms r/covidlonghaulers and r/vaccinelonghaulers
Post vaccine long term symptoms react19.org
Israeli study talking about breakthrough infections and long covid - claiming 19% had long covid. Unclear how many had neurological symptoms. https://www.nejm.org/doi/full/10.1056/NEJMoa2109072
The Neurological Manifestations of Post-Acute Sequelae of SARS-CoV-2 Infection (just infection). https://link.springer.com/article/10.1007/s11910-021-01130-1