One reason that babies get a lot of colds is that their immune systems are immature, making them more vulnerable to illness. Also, your child can develop immunity to only one of the more than 200 different viruses that cause the common cold at a time. Think of all the colds you've had in your lifetime. Your baby would have to get all of those — and more — to be immune to all cold viruses.

As your baby grows, he's likely to be exploring a lot and touching (and licking!) everything, so it's easy for him to pick up a cold virus on his hands. Then all he has to do is put his fingers in his mouth or nose or rub his eyes, and the virus will get a chance to set up shop.

Your baby may get sick more often during the fall and winter months because cold air and indoor heating dry out his nasal membranes, making it easier for a cold virus to get a foothold there. He also spends more time during cold weather cooped up indoors, where viruses can spread more easily from one person to another.

Most children average between six and ten colds per year. In families with children in daycare or school, the number of colds can reach 12 per year! (The average adult gets two to four colds annually.)

babycenter.com