Professor Luke O'Neill says there's been a "huge breakthrough" in research into the potential causes of multiple sclerosis.

MS is a condition affecting around three million people globally.

Scientists - led by researchers at Harvard TH Chan School of Public Health - have now discovered that MS might be caused by a virus called Epstein-Barr virus (EBV).

The authors of the study say the possibility of a link has been investigated for several years, but this is the first research "providing compelling evidence of causality".

The findings are so significant there's now a major effort underway to start work on an EBV vaccine, and there are even hopes the findings could help the possibility of a cure for MS being discovered in the future.

Professor O'Neill, Professor of Biochemistry at Trinity College Dublin, spoke to The Pat Kenny Show about the news.

He explained: “For years we’ve wondered what causes this disease. It involves paralysis and all sort of symptoms - the nerves in your brain effectively degenerate.

“There’s a huge breakthrough - they’ve found MS might be caused by a virus, and that has all kinds of consequences.

“Even more interestingly, it might extend to other autoimmune viruses as well.

“But if you’re EBV-positive in your teens, you have a 32-fold increased risk in developing MS."

EBV

EBV is a very common virus and causes conditions such as glandular fever (the so-called “kissing disease”, as it most often spread through saliva).

The symptoms are generally very mild and, of course, not everyone who has EBV goes on to develop MS - so researchers will now look at whether genetic or environmental factors could also be at play when it comes to MS.

Professor O'Neill said it could be similar to the way HPV is linked to cervical cancer.

He explained: "Lots of people get that virus and don’t develop cancer, so they must have some genetic thing as well for that to progress into cancer.

“We vaccinate everyone against HPV now. The same might be the case with [EBV and] MS.”

As part of the research, scientists looked at millions of samples from soldiers who had signed up to the US Army.

Professor O'Neill said: “They dug into those samples and they figured out who had MS and who didn’t. That’s where they found the EBV.

“They found it in the samples before symptoms began - that suggested it was triggering the disease.

“It was a very nice piece of detective work. The numbers are so high - 10 million soldiers were assessed overall.”

As research into MS and its causes continues, an effort is now also underway to find an EBV vaccine.

Professor O'Neill said: “This is another COVID dividend - Moderna, who made the vaccine for COVID, have now started [work] on an RNA vaccine against EBV.

“It will take a while to prove this, of course. But there’s massive optimism that if we can give an EBV vaccine to teenagers… a lot of MS could go.”