Can the shingles vaccine really reduce dementia risk?

A growing number of studies suggest shingles vaccination may reduce your risk of dementia. The consistency is intriguing — but the strength, and the limits, of that evidence deserve closer scrutiny.

In recent months, readers have asked what I think about the shingles vaccine.

Most are referring to the Welsh “natural experiment” published last year in Nature, which reported that people vaccinated against shingles had a lower risk of being diagnosed with dementia.

Headlines quickly followed, claiming the shingles vaccine reduces dementia risk by 20% and may even “slow dementia progression.”

It sounds impressive — a vaccine that appears to outperform any currently approved dementia drug.

Some readers tell me their doctors are now recommending vaccination on that basis alone.

But before making decisions based on that claim, it is worth looking carefully at what the evidence actually shows.