^

That's the most important thing. Anyone whom suffers from cold sores can tell you how important this is.

Many Virus are very easy to kill outside the body. Most perish with soap and water. However, once in the human body, only the immune system can deal with it. Having a strong immune system is the primary key in preventing or shortening colds.

Some claim that Zinc, Vitamin C, Echinacia, Vitamin D, L-Lysine, and a few other supplements and vitamins help the body develop and maintain a strong immune system. Most health experts will say that healthy eating, enough sleep and moderate regular exercise while controlling stress are probably the biggest aid in strengthening the immune system.