How common is the cold sore virus?
Cold sores have been described for thousands of years and it is said that the Roman Emperor Tiberius banned kissing because so many people were affected by the problem.
Cold sores typically affect the mouth and nose, and are caused by a virus known as herpes-simplex virus type 1 (HSV-1). Although named as a ‘herpes’ virus, HSV-1 should not be confused with herpes-simplex virus 2 (HSV-2), the cause of genital herpes.
Cold sore viruses are usually picked up during childhood but lie dormant until years later (usually in young adulthood) when they reactivate. This causes the characteristic unsightly and embarrassing blisters which last between 7 and 10 days.
Most of us carry the HSV-1 virus in our bodies with estimates running as high as 90% of the population. However, only 20% of people in the UK suffer from cold sores – so why is this so? Why don’t all people with the virus experience outbreaks of cold sores?
This question has puzzled scientists for many years. Doctors have known that cold sores appear when the immune system is ‘run-down’ such as when under stress, or with the common cold – in fact, it is said this is reason the name ‘cold sores’ came about and why they are also called fever blisters.
What has the new research found?
This association with the immune system has only been properly confirmed recently – scientists have discovered that a particular immune protein produced by the body, called interferon-l, is key in determining whether or not cold sores develop.
Interferons are a diverse group of chemicals produced naturally by the body in response to infection. They have a wide range of functions, including controlling the body’s immune response and inflammation.
This new research suggests that people who do not produce enough interferon- l may lack a specific gene and are hence more prone to cold sores. This helps explain why not everyone carrying the cold sore virus (HSV-1) suffers the problem – if you have the gene, the HSV-1 inside you won’t get the chance to activate.
 Griffiths S, Koegl M, Boutell C, et al. A systematic analysis of host factors reveals a Med23-interferon- regulatory axis against herpes simplex virus type 1 replication. PLoS Pathog 9(8): e1003514. Doi:10.137/journal.ppat.1003514
So what does this all mean?
If the research is correct, some people will simply be more prone to cold sores as you cannot (easily) change the genes you have. However, the research does confirm the key role of interferons in the immune system when it comes to developing cold sores, and there are many things you can do to keep your immune system strong.
Being more careful with what you do and eat especially when you are extra busy at work or in your personal life, and being on the lookout for times when stress starts to affect your immunity, will all help.
The new research suggests that cold sores might be controlled using specific medicines. However, these are still in the future. What we have now is Echinacea which has well-established and specific benefits for the immune system. This is how it helps the body fight off the symptoms of colds and flu.
Research on Echinacea confirms that the immune strengthening effects are particularly relevant when the body is under stress.  All of this explains why, over the years, people have found Echinacea to be of benefit in fighting viral infections such as the common cold, flu and also, why it can help cold sores.
 Ritchie MR, Gertsch J, Klein P, Schoop R. Effects of Echinaforce® treatment on ex vivo-stimulated blood cells. Phytomedicine. 2011 Jul 15;18(10):826-31.