Shingles vaccine reduces dementia risk by 17%

The study, conducted on more than 200,000 people by researchers from Oxford University and funded by the National Institute for Health and Care Research (NIHR) Oxford Biomedical Research Centre (OH BRC), found at least 17% reduction in dementia diagnoses over six years after participants were given a new recombinant shingles vaccine (Shingrix)equivalent to 164 or more extra days lived without dementia. The findings are published in the journal Nature.

The advantage was observed in both sexes, but among women this figure was higher, and the results suggest that the recombinant herpes zoster vaccine may have additional value in terms of protection against dementia.

This is a tile a painful and serious condition that affects many older people. It is caused by the shingles virus, which can be exacerbated in people who have previously had chickenpox. After the shingles vaccine (Zostavax) was introduced in 2006, several studies suggested that the risk of dementia may be lower in people who had the vaccine, although the results were inconclusive. In many countries, including the UK and US, Zostavax has been withdrawn and replaced by a much more effective vaccine (Shingrix). In the UK, the NHS offers Shingrix to all older people and other groups.

In a new study, researchers from the University of Oxford and the National Institute for Health and Care Research (NIHR. used the TriNetX electronic medical record network (a research network that combines electronic health record data from Stony Brook University with data from 110 other health care institutions) from the United States. In the U.S., the switch from Zostavax to Shingrix occurred in October 2017. This allowed researchers to compare the risk of developing dementia six years after taking Shingrix versus similar people who received Zostavax. There were more than 100,000 people in each group. Shingrix was also compared with people who received vaccines against other infections (influenza and tetanus, diphtheria, and pertussis).

Shingrix was associated with a 17% lower risk of dementia than Zostavax and a 23% to 27% lower risk than other vaccines.. This equivalent to an increase in life expectancy of 5-9 months without dementia

for those who received the Shingrix vaccine, compared with other vaccines. The positive effect was observed in both sexes, but it was stronger in women than in men.

Several additional analyses have shown that these results are reliable, but the researchers say that More research is needed before any suggestions can be made about whether the shingles vaccine should be used to prevent or delay the onset of dementia.

Doctor Maxim TakeAn NIHR clinical professor at the Department of Psychiatry at Oxford, who led the study, said: “The size and nature of this study make these results compelling and should motivate further research. They support the hypothesis that shingles vaccination may prevent dementia. “If these results are confirmed in clinical trials, they could have major implications for older people, health services and public health.”

In its turn, John ToddProfessor of Precision Medicine at the Nuffield School of Medicine at the University of Oxford, said: “The key question is how does the vaccine produce its apparent benefit in protecting against dementia? One possibility is that infection with the shingles virus may increase the risk of dementia, and therefore by inhibiting the virus the vaccine may reduce this risk. In addition, the vaccine also contains chemicals that may have various beneficial effects on brain health.”

Finally, Paul HarrisonProfessor of psychiatry and director of the Molecular Targets study at Ohio State University, who led the study, said: “The results are intriguing and encouraging. Anything that can reduce the risk of dementia is welcome, given the large and growing number of people who suffer from it.”

A free shingles vaccine is available in the UK for people aged 65, people aged 70 to 79 and people aged 50 and over who have a severely weakened immune system. Older shingles vaccines are being replaced by the Shingrix vaccine, made by the pharmaceutical company GlaxoSmithKline (GSK).