Shingrix Vaccine May Reduce Dementia Risk

Older adults who receive the latest shingles vaccine may experience a notable reduction in their chances of developing dementia, according to new research. Dr. Sheona Scales, director of research at Alzheimer’s Research UK, emphasized that dementia is primarily caused by diseases such as Alzheimer’s, rather than being an unavoidable part of aging. She highlighted the importance of discovering new methods to minimize the risk of these diseases and pointed to research indicating that the Shingrix shingles vaccine might lower the risk of dementia.

A six-year study revealed that individuals who were administered the newer "recombinant" shingles vaccines, such as Shingrix, had 17% more time without a dementia diagnosis compared to those who received the older "live" vaccine, Zostavax. Dr. Scales, who was not part of the research team, noted the need for further investigation to understand how the vaccine might reduce dementia risk and whether it is directly responsible or if another factor is influencing the outcome.

The research was published on July 25 in Nature Medicine. Professor Andrew Doig, a biochemistry expert at the University of Manchester, mentioned that there has been a long-held suspicion of a connection between herpes zoster virus infection, which causes chickenpox and shingles, and the onset of dementia. He referenced earlier evidence suggesting that the older live Zostavax vaccine could potentially lower the risk of Alzheimer’s disease.

In 2017, healthcare providers began transitioning from live vaccines to the newer recombinant vaccines like Shingrix. The U.S. Centers for Disease Control and Prevention (CDC) now recommends that everyone aged 50 or older receive the Shingrix vaccine to prevent shingles and its complications.

The study, led by Maxime Taquet from the University of Oxford, analyzed data from nearly 208,000 individuals in the United States who received a shingles vaccine between 2014 and 2020. Approximately half of these patients received the older Zostavax vaccine, while the other half were given the newer Shingrix vaccine. Six years post-vaccination, individuals who received Shingrix had 17% more time without a dementia diagnosis, equating to an additional 164 days on average without dementia.

Interestingly, the benefit was slightly more pronounced in women compared to men. The study also found that this protective effect seemed specific to the shingles vaccine, as other vaccines commonly administered to older adults, such as the flu shot and the Tdap vaccine (for tetanus, diphtheria, and pertussis), did not show the same neurological benefits.

Regarding the potential link between the herpes zoster virus and dementia, Professor Doig explained that the connection is complex. While many people infected with the virus do not develop Alzheimer’s disease, and some who receive the new recombinant vaccine still develop the disease, a vaccine alone is unlikely to completely prevent Alzheimer’s. Various factors, including genetics, cardiovascular health, and head injuries, also play significant roles in determining dementia risk.

Despite these complexities, Doig stressed that addressing the herpes zoster virus appears to be a promising strategy in combating dementia. He advocated for continued efforts in this direction to tackle what he described as a devastating and costly disease.