I think the folk up in my neck of the woods seem to have them about as much as that! Perhaps we're all just full of germs up here in Scotland

I rarely get colds now, perhaps one nasty one a year, and I used to get them really quite often growing up.
I've found one of the main factor for this lack of sickness to be my diet.
I eat a lot of spicy food! And it really does get rid of germs.
My mum is pretty much curry mad and she'll get one every few years.
It just cleans out your system (and your nose). Plenty of onions and a good few chillies, I used about 4 Birds Eye chillies in a curry.

If hot food isn't your thing, then I also find Vitamin C does help, as has been mentioned. I have a glass of fresh orange a day and feel revitalised afterwards. Perhaps you could also try herbal teas, there are so many different varieties all designed to aid different things, so choose one to keep you and your immune system healthy.

And if nothing helps, stay positive and let it run its course!