I think they say it is something to do with zinc deficiency so maybe consider taking a supplement for prevention in the future.
No, it's a virus. And a herpes virus at that. So one to be avoided. It takes up residence in nerve cells and re-occurs periodically once an individual is infected with it.
Zovirax is the cream to use. Put it on frequently - hourly if possible - and it will go away in a couple of days. If it's the first infection and you're lucky and very quick with the cream it might be banished. Otherwise it gets in deep and never leaves you. It's related to Chicken pox, which re-occurs in some people as shingles. The mechanism is very similar, taking up residence in nerve cells.
There is also a prescription oral treatment called Aciclovir which also helps. But you won't get that prescribed until the infection is serious and too late to stop becoming permanent. So Zovirax is the first line of defence, and the most important to use. I've not had a cold sore, but I know plenty of people who have, and all the ramifications, and I keep a tube of Zovirax for just in case. Some supermarkets sell it in 2g tubes.
Bear in mind also that it can re-locate to all parts of the body, particularly soft tissue, genitalia etc, and can be a really horrible infection. Which is very important for sex workers to be aware of, and very appropriate on this forum in case anyone thinks it's off topic.