Shingles Vaccine May Reduce the Onset of Dementia, Study Finds

The zoster vaccine recombinant (Shingrix; GlaxoSmithKline) for shingles may prevent the onset of dementia, according to findings published in Nature Medicine by researchers from the University of Oxford. In a study of over 200,000 people, they found that recombinant shingles vaccines reduced risk of dementia by at least 17% in both men and women, with a greater protective effect in women.^1,2

Shingles is a viral infection caused by the varicella-zoster virus, which is the same virus that causes chickenpox. Image Credit: © kitsawet - stock.adobe.com

According to the Alzheimer’s Association, approximately 7 million individuals in the US are living with Alzheimer’s and dementia, and the number is expected to reach nearly 13 million by 2050. Standard of care treatments for dementia include cholinesterase inhibitors, memantine (Namenda; Actavis Plc), and other medications to treat symptoms associated with the condition. Additionally, patients may incorporate lifestyle modifications such as improved diet, exercise, and changes to their physical environment. However, these therapies only delay the worsening of dementia, meaning the best treatment for dementia is to prevent its onset.^3,4

Shingles is a viral infection caused by the varicella-zoster virus, which is the same virus that causes chickenpox. After a chickenpox infection, the virus stays in the body and may reactivate as shingles years later. Shingles can occur anywhere on the body and causes painful rashes and blisters, typically found around the torso. It is not life-threatening but can be a painful illness and early intervention is key to shortening the infection.⁵

The first shingles vaccine was the zoster vaccine live (Zostavax; Merck & Co, Inc) developed in 1995 and approved by the FDA in 2006. It used live cultures, similar to chickenpox and MMR vaccines. However, many patients with compromised immune systems are not eligible for live virus vaccines. In response, researchers developed zoster vaccine recombinant, which was approved in 2017 and led to the discontinued use of zoster vaccine live. The recombinant vaccine is made from a piece of the varicella-zoster virus, making it a safer, more accessible option for patients. It is given in 2 doses, with the second administered 2 to 6 months after the first injection.⁶

Emerging data suggest that zoster vaccine recombinant may protect against dementia; however, existing research is limited and refers primarily to zoster vaccine live. Prior studies suggested the potential of live vaccine in reducing the risk of dementia, leading researchers to investigate the impact of the recombinant vaccine to have a similar preventative effect.^1,2

The researchers studied the health outcomes of over 200,000 patients who received either zoster vaccine recombinant or zoster vaccine live. According to their findings, zoster vaccine recombinant was associated with a more significant impact on dementia risk compared with the live vaccine. In the 6 years post-vaccination, patients who received the recombinant vaccine had a 17% reduced risk of dementia. Additionally, when compared with other vaccines, such as flu, tetanus, diphtheria, and pertussis, the recombinant vaccine reduced dementia risk by 23% to 27%.^1,2

The researchers suggest multiple underlying causes explaining the preventative effect of the recombinant vaccine. Shingle may increase the risk of dementia, so preventing the virus may also reduce risk. Alternatively, the adjuvants present in the vaccine may have beneficial effects on brain health.1

Further research is needed to confirm a direct association between dementia risk and zoster vaccine recombinant; but the size, nature, and results of the study demonstrate promising findings that indicate the need for continued study.

REFERENCES

1. Shingrix, the shingles vaccine, could reduce your risk of dementia. Forbes. July 28, 2024. Accessed July 30, 2024. https://www.forbes.com/sites/grrlscientist/2024/07/28/shingrix-the-shingles-vaccine-could-reduce-your-risk-of-dementia/
2. Taquet M, Dercon Q, Todd J.A., et al. The recombinant shingles vaccine is associated with lower risk of dementia. Nat Med. July 25, 2024. doi:10.1038/s41591-024-03201-5
3. Alzheimer’s disease facts and figures. Alzheimer’s Association. 2024. Accessed July 30, 2024. https://www.alz.org/alzheimers-dementia/facts-figures
4. Dementia. Mayo Clinic. July 10, 2024. Accessed July 31, 2024. https://www.mayoclinic.org/diseases-conditions/dementia/diagnosis-treatment/drc-20352019
5. Shingles. Mayo Clinic. August 20, 2022. Accessed July 31, 2024. https://www.mayoclinic.org/diseases-conditions/shingles/symptoms-causes/syc-20353054
6. New shingles vaccine edges out its predecessor. Jefferson Health. Accessed July 31, 2024. https://www.jeffersonhealth.org/your-health/living-well/newer-shingles-vaccine-edges-out-its-predecessor#:~:text=The%20first%20shingles%20vaccine%20was,chicken%20pox%20or%20MMR%20vaccines