I have written a lot about how the shingles and RSV vaccines can reduce your risk of dementia, but two other vaccines have a similar effect. There is a growing body of evidence that vaccines prevent infectious diseases that are linked to a greater risk of dementia and Alzheimer’s disease (the most common form of dementia).

For older individuals, the vaccines I’m going to discuss help prevent infectious diseases that are dangerous and can lead to hospitalization or death. These vaccines not only can save your life, but also can lead to a productive and enjoyable life by reducing the risk of neurodegenerative diseases.

This article will review the research on each of these vaccines’ effects on dementia, plus potential reasons why vaccinating may have an impact on dementia.

Shingles vaccine

Shingles (also called herpes zoster) is an infection that causes a painful rash. It is caused by the varicella-zoster virus (VZV). This is the same virus that causes chickenpox.

After you have chickenpox, the virus stays in your body, “hiding” in parts of your nervous system to avoid the immune system. Shingles may not cause problems for many years. As you get older, the risk of the virus reactivating and causing shingles increases.

There are two ways to prevent shingles:

1. Never get chickenpox in the first place. The chickenpox (or varicella) vaccine prevents the disease, so the varicella-zoster virus does not enter the body to cause shingles later. Chickenpox is a very infectious disease, so you would have to be incredibly lucky not to catch it without the vaccine.
2. The CDC recommends the shingles vaccine (Shingrix™), sometimes called the zoster vaccine, a relatively new, safe, and effective vaccine that prevents shingles. Shingrix has replaced the older shingles vaccine, Zostavax, because it is much more effective.

A 2025 study published in Nature showed that the shingles vaccine (older Zostavax vaccine, which was replaced by Shingrix) reduced the risk of dementia by 20%. Another study in Australia confirmed that the shingles vaccine reduced the risk of dementia.

If you are eligible for the shingles vaccine (>50 years old in the USA), you should probably get the vaccine, irrespective of your desire to decrease your risk of dementia. Shingles is a painful disease that can lead to lifelong chronic pain or other serious complications.

RSV vaccine

The RSV vaccine prevents respiratory syncytial virus (RSV) infections. RSV is a common respiratory virus that usually causes mild, cold-like symptoms. However, it can develop into serious lung infections, especially in infants, older adults, and people with serious medical conditions.

In a 2025 paper published in NPJ Vaccines, the researchers tracked over 430,000 people and found that the RSV vaccine (as well as the shingles vaccine) was associated with a reduced risk of dementia over 18 months compared with those who received the flu vaccine.

Once again, the RSV vaccines prevent a serious disease that causes approximately 6,000 to 10,000 deaths in people 65 or older every year in the USA. Like with the shingles vaccine, reducing the risk of dementia is a bonus (though an important one).

Tdap vaccine

The Tdap vaccine, which prevents tetanus, diphtheria, and pertussis (whooping cough), is the adult version of the vaccine. The DTaP vaccine is the version for children.

A 2022 study published in the Journal of the American Geriatrics Society
examined over 200,000 patients and found that older adults who received both the shingles and Tdap vaccines had a further reduced risk of dementia compared with those who only received one of the vaccines. In other words, individuals who received both vaccines had a 50% lower risk of developing dementia compared to those who received no vaccines.

Flu vaccine

The annual seasonal flu vaccine prevents the current circulating strains of the flu.

In a 2023 study published in Neuron, influenza and pneumonia (a complication of flu) are associated with five neurodegenerative diseases, including dementia and Parkinson’s disease.

In a 2022 study published in the Journal of Alzheimer’s Disease, researchers at the University of Texas Health Science Center analyzed a health database of over 1.8 million adults, ages 65 and over. They determined that the group who received at least one flu vaccination was 40% less likely to develop Alzheimer’s disease during the following four years.

A 2024 study published in NPJ Vaccines showed that the flu vaccine was associated with a 17% reduction in dementia.

As I mentioned with the other vaccines, the flu is not some harmless disease that can be ignored. The CDC estimates that 47 to 82 million people in the USA caught the disease during the 2024-25 flu season. And of those 27,000 to 130,000 Americans died as a result of the flu.

Why do vaccines reduce the risk of dementia?

The vaccines themselves probably do not have any direct effect on the risk of dementia. These vaccine-preventable diseases increase the risk of dementia, Alzheimer’s disease, and other neurodegenerative conditions. So, preventing the diseases reduces the risk of dementia.

A 2024 study published in Nature Aging showed that severe infections, including flu, shingles, and respiratory tract infections (caused by RSV or flu), are linked to accelerated brain atrophy and increased risk of dementia in future years.

Much of the research on these vaccines and dementia shows correlation, not actual causation. However, there are strong indicators of causation because we also observe increased risk of dementia and Alzheimer’s disease in individuals who contract these infectious diseases.

The body of evidence supporting the claim that vaccines reduce the risk of dementia and Alzheimer’s disease is growing quickly. I think these four vaccines should be on the list of older adults to reduce the risk of dementia. It seems like a no brainer.

Citations

• Duggan MR, Peng Z, Sipilä PN, Lindbohm JV, Chen J, Lu Y, Davatzikos C, Erus G, Hohman TJ, Andrews SJ, Candia J, Tanaka T, Joynes CM, Alvarado CX, Nalls MA, Cordon J, Daya GN, An Y, Lewis A, Moghekar A, Palta P, Coresh J, Ferrucci L, Kivimäki M, Walker KA. Proteomics identifies potential immunological drivers of postinfection brain atrophy and cognitive decline. Nat Aging. 2024 Sep;4(9):1263-1278. doi: 10.1038/s43587-024-00682-4. Epub 2024 Aug 14. PMID: 39143319; PMCID: PMC11408246.
• Eyting M, Xie M, Michalik F, Heß S, Chung S, Geldsetzer P. A natural experiment on the effect of herpes zoster vaccination on dementia. Nature. 2025 May;641(8062):438-446. doi: 10.1038/s41586-025-08800-x. Epub 2025 Apr 2. PMID: 40175543; PMCID: PMC12058522.
• Levine KS, Leonard HL, Blauwendraat C, Iwaki H, Johnson N, Bandres-Ciga S, Ferrucci L, Faghri F, Singleton AB, Nalls MA. Virus exposure and neurodegenerative disease risk across national biobanks. Neuron. 2023 Apr 5;111(7):1086-1093.e2. doi: 10.1016/j.neuron.2022.12.029. Epub 2023 Jan 19. PMID: 36669485; PMCID: PMC10079561.
• Pomirchy M, Bommer C, Pradella F, Michalik F, Peters R, Geldsetzer P. Herpes Zoster Vaccination and Dementia Occurrence. JAMA. 2025 Jun 17;333(23):2083-2092. doi: 10.1001/jama.2025.5013. PMID: 40267506; PMCID: PMC12019675.
• Taquet M, Todd JA, Harrison PJ. Lower risk of dementia with AS01-adjuvanted vaccination against shingles and respiratory syncytial virus infections. NPJ Vaccines. 2025 Jun 25;10(1):130. doi: 10.1038/s41541-025-01172-3. PMID: 40562756; PMCID: PMC12198376.
• Wiemken TL, Salas J, Morley JE, Hoft DF, Jacobs C, Scherrer JF. Comparison of rates of dementia among older adult recipients of two, one, or no vaccinations. J Am Geriatr Soc. 2022 Apr;70(4):1157-1168. doi: 10.1111/jgs.17606. Epub 2021 Dec 12. PMID: 34897645; PMCID: PMC9300193.
• Zhao H, Zhou X, Fu K, Duan Y, Wen Q, Wang S, Zhan S. Prospective cohort study evaluating the association between influenza vaccination and neurodegenerative diseases. NPJ Vaccines. 2024 Mar 2;9(1):51. doi: 10.1038/s41541-024-00841-z. PMID: 38431710; PMCID: PMC10908860.

Help the Skeptical Raptor keep writing about vaccines

There are four ways you can help contribute to keeping this website running at full speed:

1. GoFundMe.
2. Contributing via Patreon.
3. Buying on Amazon.
4. Sharing this article on Social Media.