A vaccine for avoiding multiple sclerosis has moved a step closer, as doctors believe they have discovered the cause of the disease, The Daily Mail says.
MS develops following two separate common infections which cause the body to attack itself, British research has found.
And doctors now believe the development of a vaccine against one of the viruses may hold the key to future MS prevention.
The neurological condition is triggered when the immune system attacks the nerves, causing pain, fatigue, vision problems and spasms.
What causes the body to begin attacking itself has never been identified.
But scientists at the University of Glasgow and Harvard University in the US suggest exposure to two common infections – threadworms followed by the Epstein-Barr virus – may be the trigger.
The findings therefore suggest that developing a vaccine or drugs to stop people getting the Epstein-Barr virus could also make them immune to multiple sclerosis.
Professor John Paul Leach, consultant neurologist at the University of Glasgow, said: ‘MS is a condition where the body produces antibodies against itself for reasons that have never been understood and goes against its own nervous system. It is odd that we have never found out why some people are more prone than others.
‘There is already some evidence that exposure to the Epstein-Barr virus makes it more likely someone will develop MS but this does not offer the full explanation of why people develop this reaction. MS may be the result of not one but two infections in the right order.’
The researchers’ explanation is currently just a theory but they plan to carry out further research. Threadworms affect around one sixth of the world’s population and are a parasitic infection affecting the gut, common in children.
The Epstein-Barr virus is one of the most common viruses in humans and is the cause of glandular fever although many people only suffer mild symptoms.
Dr Patrick Kearns of Harvard University, who led the research, said: ‘I believe the missing link may be threadworm infection. This is a very common condition in children and is also common in soldiers living in barracks.
‘In areas where soldiers were billeted during the Second World War it would have spread to local populations.
‘I believe that what may be causing MS is a rare late complication of exposure to these two infections.
‘First, when the body is exposed to threadworm infection it produces an immune response and “memory” white blood cells are created and live in the immune system that could fight off the infection again. Next, if someone is exposed to the Epstein-Barr virus then even after they recover from the illness, the virus hides in the white blood cells.
‘It is already known to cause a huge number of other diseases and cancer and it could be that it causes the memory white blood cells that were created to respond to threadworms to start attacking similar cells in the human body. It may be a good idea for public health officials to treat worms at a population level.
‘But the real benefit would be developing better tools to target the Epstein-Barr virus with a vaccine or drugs.’
The research is published in the journal Multiple Sclerosis and Related Disorders.