As if battling icy temperatures wasn’t enough to cope with, new research shows that cold sore sufferers will have to endure the virus that causes their facial blemishes twice as long as previously thought.
Tests on mice, conducted as part of an Australian National University (ANU) study, reveals that the herpes simplex (HSV-1) virus may still be spreading up to 10 days after infection.
“The traditional view of viral latency, and particularly in the case of HSV-1, is that the virus is either active or not active and there’s not much in-between,” says the paper’s lead author, Professor David Tscharke from the Department of Immunology and Infectious Disease at the ANU’s John Curtin School of Medical Research.
“But now we know that the HSV-1 virus is still spreading in the nervous system at a time that most people thought the acute phase was over.
“So you might think that once the physical cold sore has gone, you are well and that the virus is entirely beaten but your immune system is still fighting it for you.”
“But now we know that the HSV-1 virus is still spreading in the nervous system at a time that most people thought the acute phase was over."
The study, published in PLOS Pathogens. shows that some of the virus’s "damaging genes" remain capable of generating proteins to restart an active infection after a blister disappears.
In fact, the oral herpes virus hides in neurons, just waiting for your immune system to drop for it to erupt again.
“This activity was also seen in the time period in-between the first active phase and when latency starts is longer than we first thought. In mice, it’s about twice as long.
“The virus finds new places to hide and now spreads for around nine or 10 days … You can’t see it [on the body] but the virus is still spreading underground.
“The virus finds new places to hide and now spreads for around nine or 10 days … You can’t see it [on the body] but the virus is still spreading underground.”
Professor Tscharke adds that the findings of this study on cold sores may translate to genital herpes.
“You can’t just assume that if someone tells you ‘I have no symptoms’ that it’s OK and it won’t spread to you. So just like all STIs, you want to protect yourself all the time.”
The next step in the battle against the herpes virus, Professor Tscharke says, is to work out how to turn the virus’s damaging genes on and off and improve the body’s immune system.
“The difficulty is that there is a lot of talk about what boosts the immune system in the popular press. But most of it has no basis in science.
“The general health advice for most people, to be active and eat well, applies here too. There are many supplements and remedies that you can buy, but these are unproven. There are effective antiviral drugs that work, but as most people with cold sores know, you need to start them early.”
More research is needed to extend the findings to people and further understand how to boost immunity to virus infection.
The Better Health Channel reports that 90 per cent of Australian adults have herpes simplex antibodies in their bloodstream, and one-third of infected people experience cold sores. It can be triggered by influenza or the common cold as well as exposure to windy conditions, hence the name ‘cold sore’.
According to the Australian Bureau of Statistics, around one in eight Australians aged 25 and over carries HSV-2.