Probably not, the vaccine was only available about 4 years ago, not enough time to follow the post-vaccination period to look for dementia development EVEN if they started the study in 2020.
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I discussed it with the new o3 model for
ChatGPT, seems that the current evidence leads in the direction that Covid vaccination helps, and perhaps a lot:
Below is the best‑quality evidence that SARS‑CoV‑2 vaccination might lower a person’s long‑term risk of dementia. I group the data from strongest to most speculative, then flag caveats.
1 Population‑scale cohort evidence
Study Design & population Dementia‑related outcome Effect size (vaccinated vs unvaccinated)
UK Biobank (Int J Infect Dis 2024) 393 k adults, median 54‑day follow‑up after ≥1 mRNA or adenoviral dose First hospital admission for dementia HR 0.11 (95 % CI 0.06–0.22) – an 89 % relative risk reduction
Israel Maccabi HMO registry (Front Public Health 2023) 25 733 older adults with pre‑existing cognitive disorders + 65 k controls 14‑mo mortality & neuro‑psychiatric deterioration Mortality 7 % (vaccinated) vs 52 % (unvaccinated); lower new antipsychotic use, suggesting slower clinical decline
Strengths: electronic‑health‑record data, adjustment for comorbidities, consistent across sensitivity analyses.
Limitations: follow‑up is short, healthy‑vaccinee bias possible, dementia incidence was secondary in the Israeli study.
2 Long‑COVID cognitive sequelae (an intermediate endpoint)
• Swedish national cohort (BMJ 2023) — 300 k vaccinated vs 290 k unvaccinated adults who later caught COVID‑19. Prior vaccination cut the risk of a post‑COVID condition (PCC) diagnosis that included cognitive impairment by 58 % (aHR 0.42, 95 % CI 0.38–0.46); each extra dose lowered risk further.
• UK community sample (NEJM 2024, >100 k participants) — average IQ‑equivalent loss after infection was smaller, and sometimes absent, in people who had multiple vaccine doses.
Because persistent cognitive deficits and vascular events are known precursors of vascular and Alzheimer‑type dementias, lowering long‑COVID burden is a plausible dementia‑prevention pathway.
3 Mechanistic & animal data
• Mouse “long‑COVID” model (Nat Immunol 2024) — a single low‑dose adenoviral‑vector vaccine given before infection blocked hippocampal IL‑1β surges, preserved adult neurogenesis, and prevented memory‑loss on the Y‑maze.
Interpretation: vaccination blunts neuro‑inflammation that can seed later neurodegeneration.
4 Indirect evidence: vaccination prevents the exposure that raises dementia risk
Large EHR studies show that SARS‑CoV‑2 infection itself raises the 1‑year hazard of a new Alzheimer’s diagnosis by ~70 % (HR 1.69 among 6.2 million U.S. seniors).
By sharply reducing infections, severe disease, strokes, and ICU stays, vaccination plausibly lowers downstream neurodegenerative risk even if the vaccine has no direct CNS effect.
5 Conflicting findings
One small database analysis (QJM 2024) reported higher short‑term Alzheimer/MCI incidence after vaccination. The authors relied on spontaneous diagnosis codes with limited covariate adjustment and could not separate detection bias from causation. No signal of excess dementia emerged in the far larger UK Biobank or Israeli cohorts above, so this remains an outlier that needs replication.
How strong is the case today?
1. Suggestive but not definitive. The only study that measured incident dementia after vaccination (UK Biobank) points to a large protective association, but follow‑up was <2 months and residual confounding can’t be ruled out.
2. Mechanistic plausibility is growing. Multiple pathways—lower viral neuro‑invasion, reduced micro‑vascular injury, damped systemic inflammation—converge on mechanisms already linked to dementia.
3. Research gaps. We still lack long‑term (>3 y) incidence data, randomized evidence, and biomarker studies in older adults.
Practical takeaway
Staying up‑to‑date on COVID‑19 boosters is already warranted to avoid acute illness; the possibility of lowering future dementia risk is an extra, still‑emerging dividend. For patients at high baseline risk (age ≥65, ApoE ε4 carriers, vascular comorbidities), that potential benefit reinforces the risk‑benefit tilt in favor of vaccination while we await longer‑term follow‑up studies.
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Did o3 use the search tool for you query? Do you have the sources?
https://pmc.ncbi.nlm.nih.gov/articles/PMC10361652/
https://www.bmj.com/content/383/bmj-2023-076990?utm_source=chatgpt.com
https://www.nature.com/articles/s41590-024-01868-z?utm_source=chatgpt.com
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These might also be of interest:
Eric Topol’s Ground Truths articles discussing the relationship between COVID-19 and dementia risks:
1. The Brain and Long Covid
Discusses UK Biobank findings showing brain atrophy and cognitive decline in individuals post-COVID-19 infection.
2. Long Covid at 3 Years
Highlights studies indicating a correlation between prior SARS-CoV-2 infection and increased risk of Alzheimer’s disease.
3. Long Covid and Cognitive Deficits
Explores the potential for increased risk of Parkinson’s disease and dementia years after COVID-19 infection.
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Thanks, @Neo I’m pretty bullish on COVID vaccines (I’ve had 4 or 5 or so).
Does anyone have a good dashboard to track viral infections in local population. It would be helpful to know when we are in middle of an infectious wave. Bad outcomes aside it’s annoying to get sick.
With AI agents maybe it will be possible to create a dashboard easily later on.
I’ve been thinking about nasal sprays to block infections as well.
In the US these might help
And
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So does Covid vaccine help or hurt when in comes to dementia?
Long Covid and Cognitive Deficits
Explores the potential for increased risk of Parkinson’s disease and dementia years after COVID-19 infection
A potential association between COVID-19 vaccination and development of Alzheimer’s disease
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Myself and my wife get a booster every year or when there is a new updated vaccine. To date we have not experienced any side effects from the vaccines. We have been getting the Moderna although the very first one yrs ago was pfizer’s i believe. On that one we got the first shot then a few weeks later had to come back for the 2nd of the shot series.
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Good to hear. I wish they would do studies to determine if T cell exhaustion could occur.
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This is a quite interesting area. At the same time, key that the nasal pray does not have any bacterial growth in it as you are spraying it so close to the brain I think?
I was a participant in the whole cycle of Novavax clinical trials and so have had every one of the vaccines and boosters. Their effectiveness has been (as documented) exemplary. Apart from the expected day of flu-like symptoms following them I have no complaints. Moreover, I may be the only person I know who has never had COVID despite being in the crowded gym at least 5 days a week (starting as soon as they reopened during the pandemic) and on airplanes regularly.
The endless delay in approving the Novavax vaccine is an appalling commentary on how corrupt the FDA approval process has been for the COVID vaccines. It has a better safety record and uses a more well-studied technology than all of the mRNA vaccines, and yet still does not have permanent approval. SMH.
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and i have never had (to my knowledge) covid either and I didn’t do anything special to avoid it other than wearing the mask back when it was “mandatory” when covid was at it’s peak…I am a gym rat too; 7 days a week 
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I took two doses of Novavax so far (if my memory serves me right) and multiple doses of mRNA.
- Novavax: Very smart bet. Almost a no brainer. I wasn’t able to find it last time in all of bay area!!! which brings us to…
- mRNA: I think the sides aren’t worth it. It’s almost as bad as getting sick if you ask me. I got the omicron variant last year, and expected it to be easier. It wasn’t! I think I’m done with it.
For further consideration: Flu vaccine (ref)
- [RCT] 11%-42% reduction in all cause mortality in RCTs and prospective cohort studies (ref, ref, ref).
- [Association] 43% reduction in all cause mortality, which was a very consistent finding across 40+ studies (ref, ref).
- [Association] All cause mortality was reduced in adults with diabetes (ref), hypertension (ref), cardiovascular disease (ref), cancer (ref).
- [Association] Lowered Alzheimer’s risk by 25-40% (ref, ref).
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The problem of relying on AI is that whenever you question some details or add results of some studies not included in the answer, the AI returns apologizing, praising your “intelligent consideration” and making the previous result different or reaching different conclusions. You cannot blindly follow the answers, you need to know the subject deeply to distinguish contexts, missing rational, and errors of interpretation. At least, that’s my experience to date.
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The Novamax looks promising. I will wait a bit.
I recently saw something saying that the Shingles vaccine limited Dementia by 11% and the article suggested other vaccines had a positive effect in this area. I’ll have to see if I can find this info.
Of course. How you prompt / formulate the questions is very important. You can see that I’ve given that feedback elsewhere on the forum when I’ve seen these models being use in a sub-optimal way.
When asking for studies or data things tend to be a bit better, but even then AIs are not yet great at weighing different sources and papers against each other.
The point here was whether there were any studies and data or not. And it seems like the answer to that is - yes, there is some.
You might find the studies linked to and discussed here relevant and helpful
Very well. Good also to remember that most of times studies give the “relative” risk, which is usually frustrating once you (if you) can translate to absolute risk. The dementia studies is just one example.
CronosTempi, thx for this post. As an MD focused on patients with Long Covid, I want to underline you comments hundred fold. My only additional comment is that the data is very clear and repeated in numerous studies: vaccine reduces the risk of LC, masking reduces the risk of Covid.
If someone prefers to drink the RFK/DJT kool aid, then nothing I can do to stop them.
But the rest of you should keep up with vaccines and mask when appropriate, eg airports, planes, crowded venues.
Belive me: you do not want to have Long Covid!!!
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