Can Some People Be Immune to Alzheimer's? What Two Real Cases Reveal
Every so often, a headline claims scientists found people who are "immune" to Alzheimer's. The latest is a video titled "Scientists Discover Alzheimer's Immunity." It sounds too good to be true — and partly, it is. Here is the real science, including the parts the headline skips.
Evidence Tier: 🥈 Silver — two landmark case reports in Nature Medicine, plus a 2026 computer-model study.
📋 Simple Summary
Some people carry a gene that should give them Alzheimer's by their mid-40s. A tiny few stay sharp for decades longer. Scientists found two of these people and are studying what protects them. The answer is a rare genetic "shield" that stops the disease from spreading in the brain. The science is real and important. But "immunity" is the wrong word — it is not a vaccine, and it does not mean anyone can avoid Alzheimer's today.
The detailed breakdown continues below for those who want the full science.
Category Tags: ⚡ Breaking Now, 🔭 On the Horizon
The two real cases
In Colombia, one big family has about 6,000 members. Many of them carry a gene mutation called PSEN1. This mutation almost always causes Alzheimer's — and early, starting around age 44.
Two people in that family broke the pattern:
- The woman. She carried the PSEN1 mutation, but also two copies of a rare "shield" variant called APOE3 Christchurch. She stayed clear-headed into her 70s. (Nature Medicine, 2019 — PMID 31686034)
- The man. He carried the same PSEN1 mutation, but a different shield called Reelin (COLBOS). He stayed sharp into his late 60s. (Nature Medicine, 2023 — PMID 37188781)
What "immunity" actually means — and what it doesn't
"Immunity" usually means your body fights off a germ, like a vaccine. That is not what happened here.
These two people did not fight off Alzheimer's. They still had plenty of amyloid — the sticky protein that clumps into plaques in an Alzheimer's brain. What they mostly avoided was the second, deadlier step: tau, a protein that forms tangles and actually kills brain cells.
Their rare genetic shield seems to have stopped the damage from spreading from amyloid to tau. In plain words: the fire started, but it never took over the house.
How the shield works (the short version)
Amyloid plaques build up first, often years before symptoms. Tau tangles come next, and tau is what closely matches memory loss. The Christchurch and Reelin shields both appear to block the tau step. Scientists are still working out exactly how.
What's genuinely new — and what isn't
The headline says "scientists discovered" this. But the first case was published in 2019, and the second in 2023. What is genuinely new is the hunt for a treatment. If scientists can copy the shield with a drug or gene therapy, they might protect everyone — not just the lucky few born with it.
That is the exciting part. But it is years away from a pill, if it ever becomes one.
The honest verdict
| Part of the claim | Verdict |
|---|---|
| "Rare people are protected from Alzheimer's" | ✅ True — well documented |
| "Scientists are figuring out how" | ✅ True — real progress |
| "Immunity" (like a vaccine or cure) | ❌ Oversold — it's a rare genetic shield, not something you can get |
What this means for you
You cannot get this "immunity" today. It is genetic — you either carry one of these rare shields or you don't.
But the research points to a real target: if scientists can copy the shield, everyone might benefit someday.
Until then, the things that actually protect your brain are the boring, proven ones — exercise, good sleep, healthy blood pressure, and staying connected to people. We covered those in detail here: Can You Prevent Alzheimer's? What the Evidence Says.
Frequently Asked Questions
Can you really be immune to Alzheimer's?
Not in the vaccine sense. A tiny number of people carry rare genetic "shields" that stop the disease from progressing, but they still develop the underlying plaques. It is protection from the damage, not immunity from the disease.
Who are the two famous protected cases?
A Colombian woman with the APOE3 Christchurch variant (published 2019) and a Colombian man with the Reelin/COLBOS variant (published 2023). Both carried a gene that usually causes Alzheimer's by the mid-40s, yet both stayed sharp for decades longer.
Does this mean there's a cure coming?
No. It means scientists now have a clear target: copy the shield with a drug or gene therapy. That work is promising but still years away from reaching patients, if it works at all.
Can I get tested for these protective genes?
Technically yes, through genetic testing. But these variants are extremely rare, and knowing your result would not change what you should do today. The same brain-health habits still apply.
What actually protects my brain right now?
Exercise, good sleep, controlling blood pressure, and staying mentally and socially active. These are proven and free — and far more relevant to most people than a rare genetic shield.
Sources
- Arboleda-Velasquez JF, Lopera F, et al. "Resistance to autosomal dominant Alzheimer's disease in an APOE3 Christchurch homozygote: a case report." Nature Medicine. 2019. PMID 31686034.
- Lopera F, Marino C, Chandrahas AS, et al. "Resilience to autosomal dominant Alzheimer's disease in a Reelin-COLBOS heterozygous man." Nature Medicine. 2023. PMID 37188781.
- Kobro-Flatmoen A, et al. "High reelin expression may explain why a subgroup of entorhinal cortex neurons functions as an initial nucleation site of Alzheimer's disease." PLOS Computational Biology. 2026. PMID 42640981.
Disclaimer: This article explains published research for information only. It is not medical advice. We cover prevention questions — not diagnosis or treatment. Always talk to your doctor about your own health. Full disclaimer →