Researchers want to find out if viruses are behind diseases in the brain
If viruses play a role in some of our most feared diseases, it could change our entire understanding of them, according to researchers.
Researchers in Bergen want to investigate whether viruses are the cause of all the neurological diseases they study, including MS, dementia, Parkinson's, and ALS. If viruses turn out to play a role, it will make these diseases easier to target.(Stock photo: Shutterstock / NTB)
Researchers now suspect that similar mechanisms might be involved in dementia. Parkinson's is also under review.
"If we find that viruses are a triggering factor, it could reshape our entire understanding of these illnesses – and how they should be treated," says Øivind Torkildsen.
He is a professor and neurologist at Haukeland University Hospital in Bergen, where he leads MS research.
Several studies show that people who have been vaccinated against shingles have a lower incidence of Alzheimer's.
Charalampos Tzoulis, professor and chief physician
Mono as a key factor
Annonse
The breakthrough in MS research came when large studies revealed that developing MS is nearly impossible without prior infection by the Epstein–Barr virus (EBV), which causes mononucleosis.
"If we can vaccinate against the mononucleosis virus, we can prevent many cases of MS," says Øivind Torkildsen.(Photo: Ingvild Festervoll Melien)
The small fraction of people who have never been infected with EBV appear unable to develop MS at all.
"We're now certain that the mononucleosis virus causes MS. The remaining question is which mechanism is responsible," says Torkildsen.
Researchers are currently exploring two main hypotheses:
Does the virus continue to stimulate the immune system, causing chronic inflammation?
Or does it trigger a process that continues on its own after the infection has taken hold?
Towards new treatments
Researchers are now testing an antiviral medication for MS called tenofovir.
"If we can suppress the virus, we might be able to stop the disease before it progresses," says Torkildsen.
Moderna is in the process of developing a vaccine against EBV. This research has reached phase 2 clinical trials, which means it's now being tested on patients.
"If we can vaccinate against the the mononucleosis virus, we can prevent many cases of MS," says Torkildsen.
He believes this new understanding opens the door to entirely new treatment strategies.
"This could represent a major shift in how we think – moving from treating only symptoms to tackling the actual cause," he says.
Dementia may share the same key
Charalampos Tzoulis is a professor and clinical neurologist. He leads the Neuro-SysMed research centre for clinical treatment, where Torkildsen also conducts research.
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In the Scandinavian countries, many are still not vaccinated against shingles. This gives researchers in Bergen certain advantages, explains Charalampos Tzoulis.(Photo: Eivind Senneset)
Tzoulis says that researchers are now investigating whether similar processes could be behind dementia-related diseases like Alzheimer's.
"In the field of dementia research, things are still more uncertain, but recently several studies have suggested that herpesviruses might be directly involved," he says.
Vaccination linked to reduced risk
Vaccination against the chickenpox virus – which belongs to the herpesvirus family – appears to significantly reduce the risk of dementia. Several individual studies indicate this.
"Multiple studies have shown that people vaccinated against shingles have a lower incidence of Alzheimer's. That's certainly interesting. But we don't yet know if there's a direct causal link. To find out, we need a randomised, controlled study," the researcher explains.
A unique opportunity
Researchers in Bergen are now in discussions with international partners about conducting exactly such a study.
Several other European countries already include the shingles vaccine in their national vaccination programmes. In the Scandinavian countries, however, many are still not vaccinated against shingles.
"It's therefore possible to create comparable groups, which makes a randomised and controlled study possible," says Tzoulis.
Øivind Torkildsen believes that, over time, Norway should also include the shingles vaccine in its national immunisation programme.
"In addition to protecting against a serious illness, the vaccine could potentially reduce dementia cases by up to 20 per cent. That represents a major public health benefit," he says.
Could transform our understanding of diseases
Tzoulis also leads the K.G. Jebsen Centre for Parkinson's Disease at Haukeland University Hospital and the University of Bergen.
When it comes to Parkinson's, researchers have even less scientific evidence of viral involvement than they do for dementia, he explains.
"But there are some findings that point towards certain types of gut viruses. That makes sense, since Parkinson's often affects the intestines early on – with constipation and digestive issues appearing up to 20 years before motor symptoms," he says, adding:
"We also have historical observations from the Spanish flu. Some who developed brain inflammation after the flu later developed Parkinson's symptoms."
This suggests that infections could play a role in certain cases, says Tzoulis.
Not enough to just kill viruses
Tzoulis, Torkildsen, and their colleagues leading research on dementia and ALS in Bergen are also seeking funding for a large EU project.
Their goal is to explore whether viruses may underlie all the neurological diseases they study, including MS, dementia, Parkinson's, and ALS. For ALS, there is even less evidence of such a link than for the others.
If viruses are shown to play a role, it could make these diseases easier to target, Tzoulis believes.
"In that case, we could treat them with antiviral medications or prevent them with vaccines," he says.
But Tzoulis stresses that it's unlikely to be as simple as killing a virus and eradicating the disease.
"There are also genetic and environmental factors involved in these conditions," he says.
