What should I do about this cold that is going through my cats?

I have five cats and recently a few of them have gotten this real bad cold. It started with one, then he got over it. Right after that another got it and now a third has gotten it.

The symptoms are: frequent sneezing, runny nose and watery eyes.

What should I do about it? Just wait it out until they are all over it? Are they any good remedies for sick cats? Should I talk to my veterinarian? Could it spread to humans?