The new recombinant shingles vaccine, ‘Shingrix,’ is associated with a reduced risk of dementia compared to an earlier shingles vaccine, according to a major new study.
Evidence from a team of scientists at the University of Oxford indicates that the newer shingles vaccine is more protective against dementia compared to the previous shingles vaccine. Both shingles vaccines were associated with a lowered risk of dementia when compared to either the influenza vaccine or the tetanus / diphtheria / pertussis (Tdap) vaccine.
The scientists studied health outcomes of more than 200,000 people who received one of the two different shingles vaccines and found that the recombinant shingles vaccine, Shingrix, reduces dementia by at least 17% more than the older, but now discontinued, live shingles vaccine, Zostavax. Further, they found that Shingrix reduced dementia risk by 23-27% than did vaccines against other illnesses. This equates to 5-9 months or more dementia-free days of life.
This protective effect was seen in both sexes, but was greater in women.
Interestingly, after the live vaccine against shingles, Zostavax, was introduced in 2006, several studies suggested it might reduce the risk of dementia. Later, Zostavax was discontinued in many countries, including the USA and UK, in favor of the much more effective vaccine, Shingrix. Unlike Zostavax, Shingrix is not a live virus vaccine. It’s a recombinant vaccine made from a piece of the virus. It’s given in two doses, with the second given 2 to 6 months after the first.
It was during this switchover between the two vaccine types that participants were identified for this comparative study. This provided the rare opportunity to compare the risk of dementia in the six years following Shingrix compared to the otherwise similar group of people who received Zostavax. There were more than 100,000 people in each group. The study also compared Shingrix to vaccines against other infections (flu and tetanus, diphtheria, and pertussis).
“The size and nature of this study makes these findings convincing, and should motivate further research,” said the study’s lead author, Maxime Taquet, a NIHR Clinical Lecturer with educational backgrounds in both clinical psychiatry and engineering.
“They support the hypothesis that vaccination against shingles might prevent dementia. If validated in clinical trials, these findings could have significant implications for older adults, health services, and public health.”
How might Shingrix protect against dementia?
“One possibility is that infection with the Herpes zoster virus might increase the risk of dementia, and therefore by inhibiting the virus, the vaccine could reduce this risk, replied co-author, John Todd, a Professor of Precision Medicine at the University of Oxford and Director of the Wellcome Centre for Human Genetics and of the JDRF/Wellcome Diabetes and Inflammation Laboratory (DIL).
“Alternatively, the vaccine also contains chemicals which might have separate beneficial effects on brain health,” Dr Todd added. These chemicals, known as adjuvants, are designed to ensure that your immune system reacts strongly to the vaccine so a lasting immune response develops.
“The Shingrix vaccine has got different and perhaps more potent chemical adjuvants in it than the previous vaccine.”
Various analyses showed that these findings are robust but further research is still needed before any suggestion can be made that the shingles vaccine itself should be used to help prevent or delay dementia onset.
“The findings are intriguing and encouraging,” said the study’s senior author, Paul Harrison, Theme Leader in the NIHR Oxford Health Biomedical Research Centre, and a Group Leader in the Oxford Wellcome Centre for Integrative Neuroimaging.
Shingles is caused by the varicella-zoster virus (VZV), which causes chickenpox, a common childhood illness. After recovery, VZV quietly hides in the nervous system for decades, but can re-emerge to cause shingles when the immune system is compromised or due to age or stress.
Shingles is a painful and potentially serious illness that can arise in people over the age of 50. Although most people recover from a shingles attack within one year, approximately one in five people will end up with post-herpetic neuralgia, which can last weeks, months, or years. These sequelae include vision damage or blindness (which are permanent), lasting pain that can be quite severe, scarring, and more.
For these reasons, the CDC recommends that adults age 50 and older should get the Shingrix vaccine to prevent shingles and the potentially severe complications from the illness. People who have already had shingles can get the Shingrix vaccine as can those who received Zostavax in the past. It’s also worthwhile to get the vaccine if you don’t know if you’ve had chickenpox as a child.
This study’s findings raise an interesting question — especially in this age of ‘anti-vaxx’ lunacy — might the public increase their uptake of the Shingrix vaccine to reduce their risk of dementia along with protecting against a dreaded shingles attack?
“Anything that might reduce the risk of dementia is to be welcomed,” Dr Harrison said, “given the large and increasing number of people affected by it.”
Source:
Maxime Taquet, Quentin Dercon, John A. Todd & Paul J. Harrison (2024). The recombinant shingles vaccine is associated with lower risk of dementia, Nature Medicine | doi:10.1038/s41591-024-03201-5
© Copyright by GrrlScientist | hosted by Forbes | LinkTr.ee
Socials: Bluesky | CounterSocial | Gab | LinkedIn | Mastodon Science | Spoutible | SubStack | Threads | Tribel | Tumblr | Twitter
