skepticalraptor.com

GSK is investigating if shingles vaccine reduces risk of dementia

GSK announced that it is investigating a group of more than a million older adults in the UK to determine whether its shingles vaccine, Shingrix, lowers the risk of dementia.

Several studies have shown that shingles increases the risk of dementia, or the shingles vaccine reduces the risk. Either way, the shingles vaccine may be linked to lowering the risk of dementia. GSK wants to confirm this link with a large epidemiological study.

This article will review what GSK is planning with its shingles vaccine.

two adult women beside each other shingles vaccine dementia

Photo by Andrea Piacquadio on Pexels.com

What is shingles?

One of the complications of contracting chickenpox, caused by the Varicella zoster virus (VZV), is that the body’s immune system does not destroy the virus. Once the symptoms of chickenpox disappear, the virus hides (it does not do this consciously, it’s a virus) in the dorsal root ganglion, a bundle of nerve fibers at the bottom of the spinal column. The virus hangs out there, hidden from the body’s immune system.

We are not sure why it does this, but it may be an evolutionary adaptation to survive until later, when it can reproduce and reinfect the victim.

Even though the body generated an immune response to the original zoster virus infection, several years or decades after the initial infection, the adaptive immune response against the virus wanes or disappears. Due to other unknown factors, possibly stress or other infections like COVID-19, the Varicella zoster virus “moves” along the nerve bundles and begins a secondary infection with much more serious consequences to the individual.

This second infection is called herpes zoster, more commonly known as shingles. This infection usually happens when the patient is older than 50, although it can happen at any time, occasionally even in young adults.

Despite chickenpox and shingles being caused by the same virus, shingles was given a different name, herpes zoster, probably because it was originally thought to be caused by a similar, but unrelated virus. However, herpes zoster is not a formal name based on biological binomial nomenclature. We now know that the virus Varicella zoster causes both chickenpox and shingles.

Singles is an entirely unpredictable disease. It appears at random points in time in response to unknown causes. Once shingles appear, they can be painful, depending on the location of the outbreak. It can cause blindness, disfigurement of the infected area, permanent pain, and other conditions.

Shingles can be treated with antiviral drugs, but only if the infection is recognized and treated within 24-72 hours, a time frame that might not allow most individuals to get to their doctor. The initial symptoms may appear like acne or other skin conditions, which many people might ignore. After 72 hours, the disease has to run its painful and dangerous course. The pain of shingles may last for weeks, months, or even years after the blisters have healed – this is not a trivial disease.

Almost all individuals in the US aged 50 years and older have been infected with VZV and are therefore at risk for shingles. There’s a growing body of evidence that herpes viruses, including VZV, can influence cognitive decline.

The only way to prevent a shingles infection is to boost the immune system with a new vaccine against the zoster virus. Shingrix (a shingles vaccine, sometimes called the zoster vaccine, available in the USA) is a relatively new, safe, and effective vaccine.

There is another way to prevent shingles — never get chickenpox in the first place. Of course, we have a vaccine for that, the chickenpox (or varicella) vaccine.

So let’s be clear about a couple of things. First, you are only at risk for shingles if you contract chickenpox. Second, children who have received the chickenpox vaccine will probably never develop shingles.

close up shot of a person with vaccine sticker

Photo by SHVETS production on Pexels.com

GSK shingles vaccine and dementia study

The British drugmaker GSK is teaming up with British institutions, the UK Dementia Research Institute and Health Data Research UK, to study the health records of about 1.4 million patients, some of whom have already received GSK’s Shingrix (recombinant shingles vaccine) and some who have not.

When the UK vaccine program for the shingles vaccine expanded in 2023, 65-year-olds upwards became eligible for the Shingrix vaccine, whereas previously only people aged 70 and over were eligible. However, those aged 66 and over at the time of the expansion were informed they could not get it until they turned 70. This meant two large patient groups were randomly assigned to distinct vaccination groups, which can provide data similar to a similarly large, but prohibitively expensive, clinical trial.

The study will examine the data until the 66-year-olds turn 70 and become eligible for the vaccine, taking into account factors such as other medical conditions.

This will provide powerful evidence about whether the shingles vaccine can reduce the risk of dementia and Alzheimer’s disease.

It’s important to note that no one thinks that the vaccine itself has any effect on dementia or Alzheimer’s disease. It’s that the vaccine prevents an infection by Varicella zoster, which may be linked to a higher risk of dementia.

That being said, I cannot wait to see the results of this study.

Citations

Help keep the Skeptical Raptor going

There are four ways you can help contribute to keeping this website running at full speed:

GoFundMe.

Patreon.

Buying on Amazon.

Sharing this article on Social Media.

Michael Simpson

Lifetime lover of science, especially biomedical research. Spent years in academics, business development, research, and traveling the world shilling for Big Pharma. I love sports, mostly college basketball and football, hockey, and baseball. I enjoy great food and intelligent conversation. And a delicious morning coffee!