Shingles Vaccine May Help Lower Dementia Risk

The shingles vaccine is already known for protecting older adults from a painful and sometimes dangerous condition. Now, new research suggests it may do even more, possibly helping to prevent or delay dementia.

In a large study published in April in the medical journal JAMA, researchers looked at the health records of about 280,000 older adults in Australia. They compared people who had received the shingles vaccine with those who had not. What they found was striking: over an average of 7.4 years, those who got the vaccine were about 20 percent less likely to be diagnosed with dementia than those who did not. That kind of difference is too large to ignore, even though the study does not prove the vaccine directly prevents dementia.

According to reporting from The New York Times, this is the strongest evidence so far linking the shingles vaccine with a lower risk of dementia. Previous studies had noticed a similar pattern, but researchers needed to rule out other factors. People who choose to get vaccinated often live healthier lifestyles overall, which also helps protect the brain. This new study used national data and a careful comparison group to reduce that bias.

The science behind the possible connection is still being explored. Experts believe that the shingles vaccine may prevent certain types of brain inflammation caused by the varicella-zoster virus. That is the same virus responsible for both chickenpox and shingles. After a person has chickenpox, the virus can remain dormant in the body for decades. In some people, especially older adults, the virus can become active again, causing the painful rash known as shingles.

When the virus reactivates, it may also trigger inflammation in the nervous system, which some researchers think could increase the risk of developing dementia later on. By keeping the virus in check, the vaccine might protect the brain as well as the body. The vaccine may also boost the immune system in ways that help fight off other processes linked to dementia.

Even without this added benefit, the shingles vaccine is already recommended for most older adults. Shingles itself can be extremely painful, especially when it affects the face or eyes. In some cases, it leads to a condition called postherpetic neuralgia, which causes long-lasting and severe nerve pain. It can also result in permanent eye damage if the rash spreads near the eye.

The Centers for Disease Control and Prevention (CDC) recommends the shingles vaccine for adults age 50 and older, even for those who do not remember having chickenpox. The current vaccine, given in two doses several months apart, is called Shingrix. It is considered safe and effective, with protection lasting for several years.

While more research is needed to confirm the dementia findings and understand the cause, experts say the new results are a promising development in public health. With dementia affecting millions of people around the world and no cure currently available, even a modest drop in risk could make a big difference.

If you are over 50 and have not yet received the shingles vaccine, now may be a good time to talk with your doctor. You will be protecting yourself from a painful illness and, possibly, giving your brain a better chance at staying healthy as you age.