Can the shingles vaccine slow ageing?

Studies show the shingles vaccine may cut dementia risk by 20% and reduce inflammation, offering new hope for healthy ageing in older adults

DEMENTIA IS tragically common among the elderly. In 2021 57m people worldwide were thought to have the condition. Ageing is a risk factor for many other ailments too, ranging from chronic inflammation to a decline in organ function. A growing body of work, however, suggests that simply taking a course of the shingles vaccine can meaningfully slow the decline. The new data suggests that it cuts risk by 20% in a range of countries.

Dementia is tragically common among the elderly. In 2021 57m people worldwide were thought to have the condition. (Shutterstock)

Shingles is a painful skin condition caused when the chickenpox virus—which can lie dormant in the body for decades—is reactivated. Although older versions of the vaccine included a live version of the virus, these have largely been replaced. Shingrix, the shingles vaccine most commonly used in America and Britain, contains small amounts of proteins taken from the virus’s surface in order to stimulate the body’s immune system to fight off the real thing.

Many public-health authorities recommend the shingles vaccine for people between 65 and 80 (although the range varies by region). The sharp age cut-offs used in the roll-out in each country or region, combined with the large number of people vaccinated, has set up a natural experiment for researchers keen to study their effects.

In recent years Pascal Geldsetzer, a researcher at Stanford University, has used this technique to examine dementia-prevalence data for populations in Australia, New Zealand and Wales. In a paper published in the Lancet Neurology this month, he and his colleagues also looked at 464,000 residents of the Canadian province of Ontario. The findings across all four regions point to the shingles vaccine meaningfully reducing the number of people who develop either dementia or mild cognitive decline later in life. “Our best guess is that shingles vaccination averts one in five new dementia diagnoses over a seven-year period,” says Dr Geldsetzer.

A study published in the Journals of Gerontology: Series A in January suggests that the encouraging results are not limited to dementia. Researchers assigned a healthy-ageing score to 3,800 adults above the age of 70, based on seven measures that included inflammation and the effects of the passage of time on DNA. The researchers concluded that those who had previously received the vaccine had significantly lower levels of inflammation as well as a better overall score.

Why exactly this might be remains unclear. One possibility, says Dr Geldsetzer, is that the seemingly dormant chickenpox virus may continuously damage the body until such time as the vaccine helps fight it off. The other possibility is that the shingles vaccine provides a broader boost to the immune system—by encouraging the production of white blood cells, for example—in which case other vaccines may yield similar benefits.

Many important questions need to be answered before public-health authorities recommend the vaccine to younger adults. Researchers still do not know how long the protective effect lasts, for one thing, or whether this effect grows with age. And, although the risk of serious side-effects in younger people is thought to be low, more data are needed.

To answer some of these questions, Dr Geldsetzer hopes to run a clinical trial soon. For now, though, he finds the evidence strong enough to get the jab himself. “If you’re going to talk the talk,” he says, “You’ve got to walk the walk.”