Vaccination slowed the progression of dementia in a “natural experiment”

Shingles vaccine prevents memory disorders for one reason or another, high-quality led by Stanford University research showed last April.

In what appeared in the Cell magazine from the beginning of the week in further research The shingles vaccine also seemed to slow the progression of dementia that had already started.

Older people in Wales who had a diagnosis of dementia at the time of vaccination did not die of dementia at the same rate as a control group that had not been vaccinated.

Vaccination could have a potential therapeutic effect, says the head of the study Pascal Geldsetzer from Stanford University, USA.

It is unclear why the shingles vaccination affects the development of dementia. One theory is that viruses that burden the nervous system and the inflammatory reaction they cause contribute to the development of dementia.

Shingles is caused by the chicken pox virus, which remains dormant in the nerve roots of the spinal cord after the disease. Almost all adults have the virus in their bodies.

When a person ages or the immune defense weakens, the virus can activate and cause shingles. The disease picture includes a blistering rash and sometimes severe pain.

A possible effect of the vaccine on memory disorders has also been shown in other studies, but it has been difficult to confirm due to confounding factors. Those who take the vaccine usually live healthier in many ways than others.

Stanford the researchers found a “natural experiment”, i.e. a research setting where the connection could be reliably examined.

On September 1, 2013, a vaccination program began in Wales where all 79-year-olds received a free shingles vaccine. Those who had reached the age of 80 before the start of the program no longer received the vaccine.

So the researchers compared Welsh people who turned 80 on both sides of the deadline within a couple of weeks.

In these two groups, determined only by the time limit, the researchers did not find any difference other than the fact that half of one group took the vaccine, but almost no one took the vaccine.

“The groups are similar except for the small age difference,” says Geldsetzer of Stanford University Medicine on the pages.

According to him, the setting was as close to a randomized experiment as possible.

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Almost half died of dementia during the nine-year follow-up period. Only a third of those vaccinated died.

The following over seven years, vaccination reduced the incidence of shingles as expected. In addition, it reduced memory disorders by a fifth.

According to a follow-up study that has just been published, the vaccination also prevented pre-diagnosis memory symptoms and other information processing difficulties in Welsh people, which were noted in the health care registers.

In addition, it appeared to slow the rate at which the disease leads to death.

Some of the Welsh people who were followed up had already been diagnosed with dementia when the vaccination program started. Half of them died of dementia during the nine-year follow-up period. In those who received the vaccination, the dementia mortality during the follow-up was one third lower than in the others.