And of course you will eventually get another cold, since there exist 300 various runny nose viruses. However you will never get the very same runny nose infection that you had in the past because you have actually developed resistance to that particular virus.Adults have actually currently had a lot of the cold viruses. Adults have developed immunity to the ones they have had. So there are not lots of cold viruses around for grownups to acquire. That is why grownups only get infected with a couple of colds annually and kids acquire a dozen runny noses per year.