How does your immune system help you fight colds and flu?

When you're feeling fit as a fiddle, you tend not to think too much about your immune system. But given that we're in the middle of cold and flu season, chances are many of us are wondering how our bodies ward off diseases.

All around us are bacteria, viruses, parasites and a whole host of other nasties that have the potential to make us very ill. Yet amazingly, most of us don't get sick that often.

Read more...http://www.abc.net.au/news/2015-08-06/how-does-your-immune-system-help-you-fight-colds-and-flu/6650768