Being vaccinated against shingles may also help delay getting a dementia diagnosis - a study in the journal Nature Medicine suggests. The work builds on previous suggestions that a shingles jab may have this unintended benefit. Researchers compared some 100,000 people who had a new shingles jab to a similar group who had an older one.
On average, those who had the new jab had an extra 164 days free from a diagnosis of dementia over six years. Further work is needed to prove the link, scientists say. Shingles is a painful, serious condition that is more common in older people.
It is caused by a reactivation of the Herpes zoster virus - the virus that causes chicken pox. A vaccine against shingles was introduced in many countries about 18 years ago. Since then there has been growing evidence that the jab could help protect against dementia - but no conclusive proof.
In this study, researchers from the University of Oxford compared the health records of people in the US who had the older Zostavax jab with a newer jab, called Shingrix, which is increasingly used in the UK. While similar numbers still got dementia by the end of the study, the researchers found, on average, over the six-year period: Study author Prof Paul Harrison said: "Even if it is a delay of 164 days, for example, on the public health level, that would not be a trivial finding. "It is a big enough effect that if [the link is proved] it feels meaningful to us.
" Dr Sheona Scales, at charity Alzheimer’s Research.