A shingles vaccine could delay the onset of dementia, according to a new study. — dpa
The shingles vaccine given to people in Britain could delay the onset of dementia, according to a new study.
The finding, which experts say is “convincing”, shows that the adjuvanted recombinant zoster vaccine is linked to at least a 17% drop in dementia diagnoses in the six years after vaccination than the previously-used live zoster vaccine.
University of Oxford researchers said that people could expect five to nine more months of life without dementia for those given the adjuvanted recombinant zoster vaccine, compared with other vaccines.
Both men and women benefited from the newer jab, but the effects were greater in women, the study found.
How does it work?
Shingles is a common condition that causes a painful rash.
It can sometimes lead to serious problems such as deafness, long-lasting pain and blindness.
Shingles occurs most often as people get older and is more likely to cause serious problems in older age groups.
ALSO READ: I'm suffering from a painful, blistering rash called shingles
Oxford Psychiatry Department academic clinical lecturer Dr Maxime Taquet, who led the study on more than 200,000 people, said: “The size and nature of this study makes these findings convincing and should motivate further research.
"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.”
Oxford’s Nuffield Department of Medicine professor of precision medicine Dr John Todd said: “A key question is, how does the vaccine produce its apparent benefit in protecting against dementia?
"One possibility is that infection with the herpes zoster virus (which causes shingles) might increase the risk of dementia, and therefore, by inhibiting the virus the vaccine could reduce this risk.
"Alternatively, the vaccine also contains chemicals that might have separate beneficial effects on brain health.”
Dr Taquet said the team’s interpretation of the data is that the jab works to delay dementia rather than prevent it altogether, although more work is needed.
Study results
In the UK National Health Service (NHS), people are offered two doses of the adjuvanted recombinant zoster vaccine when they turn 65, as long as their birthday was on or after Sept 1, 2023.
Those who turned 65 before this date are eligible for the vaccine when they become 70, while all people aged 70 to 79 are also eligible.
People aged 50 and over with a severely weakened immune system are also offered the vaccine.
Evidence shows that the the adjuvanted recombinant zoster vaccine can provide at least a decade of protection against shingles after the first jab.
For the new study, published in the journal Nature Medicine, researchers wanted to use emerging, but limited evidence that the previous live zoster vaccine might also protect against dementia.
In the United States, the live zoster vaccine was replaced by the adjuvanted recombinant zoster vaccine in October 2017, giving a good opportunity to compare the two vaccines.
Researchers looked at people’s risk of dementia in the six years following the introduction of the adjuvanted recombinant zoster vaccine, and compared them with otherwise similar people who had received the live zoster vaccine.
Some 103,837 people were in each group.
The adjuvanted recombinant zoster vaccine was also compared with people who had received vaccines against other infections, i.e. for the flu, and tetanus, diphtheria and pertussis (Tdap).
The results showed the adjuvanted recombinant zoster vaccine was associated with a 17% lower risk of dementia than the live zoster vaccine, and 23%-27% lower risk than with the other vaccines.
There was more benefit in women than men, with women enjoying 22% versus 13% more time lived without a diagnosis of dementia.
Alzheimer’s Research UK research director Dr Sheona Scales welcomed the study, but said further research was needed.
She said it "isn’t clear how the vaccine might be reducing risk, nor whether the vaccine causes a reduction in dementia risk directly, or whether there’s another factor at play”.
She added: "While research into whether vaccines affect dementia risk continues, people should be aware that there are other factors that have definitively been linked to an increased dementia risk.
"These include things like smoking, high blood pressure and excessive alcohol consumption.” – By Jane Kirby/PA Media/dpa
