No they are not. The cold is a virus and anti-biotics do not work on a virus. Most colds last for up to a week and a half. That goes the same with the Flu. The Flu vaccine only prevents *some strains of theflu, not all of them. The media tells a differnt story.
They give anit-biotis to alleviate any side effects such as a bacterial infection. IMHO opinion they give out anti-biotics way too often. The human body does wonders but the immune systems are getting so resistant to these anti-biotics that our own systems cannot work properly. Our body's immune system is supposed to work in building it's own antibodies, but with too many anti-biotics it cannot function properly.