Perchance have you hitherto endured a common cold? Maybe did you heal from the infection? Obviously you did! You won't treat a common cold directly, yet your immune system generally develops resistance to any cold virus within several weeks. We call that healed by your own immune response!Grownups have previously had a lot of the runny nose viruses. Parents have established immunity to the ones they have suffered from. So there are not so many cold viruses remaining for adults to acquire. That is why adults only succumb to a couple of colds annually whereas children succumb to 10-12 runny noses annually.