Vaccines that help prevent catastrophic shingles may offer a boon against cognitive decline. In a new study published Thursday, scientists have found that the latest shingles vaccine, Shingrex, is associated with a reduced risk of dementia. However, further research is needed to confirm a cause and effect relationship and to better understand how this effect may occur.
Singles Varicella is caused by the zoster virus, the same germ that causes chicken pox in children and young adults. Chicken pox is usually a short-lived but uncomfortable illness, but the virus manages to evade destruction from our body’s defenses by laying dormant in our nervous system. Decades later, the virus can reemerge and trigger a new infection, which we call shingles (about one-third of chicken pox patients will eventually develop shingles). Shingles is often a terrifying experience, causing symptoms such as pain, skin rashes and fever for up to five weeks. Some develop chronic nerve pain that can last for months or even years, while an unlucky few may experience multiple episodes of shingles.
Fortunately, since 2006 there has been a vaccine for shingles, Zostavax. Zostavax has been replaced by the Shingles vaccine (first approved in 2017), which still appears effective in preventing shingles, providing 90% protection for at least seven years. Shingrix is a recombinant vaccine that uses parts of the target virus to suppress immunity, whereas Zostavax uses a weakened version of the whole virus; This means that Shingrix is safe to use in people with weakened immune systems. As of 2020, only Shingrix is available for use in the United States and is recommended for anyone over age 50.
A way to prevent dementia?
There have been many studies over the years mouse The Zostavax vaccine may reduce the risk of dementia, but relatively little research has looked at Shingrix so far. This new study by scientists in England, Published In the magazine Natural Medicine, It aims to do that.
Researchers analyzed the health records of more than 200,000 people in the U.S. who had been vaccinated for shingles, half of whom were given Shingrix. They found that those given Shingrix were 17% less likely to develop dementia over a six-year period than those given the older Zostavax vaccine. They were less likely to develop dementia than the two other common vaccines used in the elderly, the flu and tetanus/diphtheria/pertussis vaccines (these groups served as a sort of control). Even among those who developed dementia, the researchers estimated that the Shingrix vaccine was associated with a six-month delay in symptoms compared with Zostavax.
These types of studies alone cannot be used to prove that Shingrix vaccine can prevent or slow dementia. If this protection is real, the question remains as to how it happens. Some research has suggested that certain germs, including herpes viruses such as varicella zoster, can directly trigger dementia, for example, although this link has not yet been confirmed. At the very least, the scientists say their work should inspire more definitive research looking at this link.
“These findings should prompt studies investigating the mechanisms underlying protection and facilitate the design of a large-scale randomized controlled trial to confirm the potential additional benefit of the recombinant shingles vaccine,” they wrote in their paper.
