And sure you will possibly get infected by one more runny nose virus, because there remain 300 different cold viruses. However you will never get the same cold virus that you had previously since you have actually created resistance to that particular cold virus.Adults have in the past had a lot of the cold infections. Parents have actually acquired immunity to the ones they have actually had. So there are not quite as many runny nose infections around for grownups to catch. That is why grownups just get a couple of runny noses per year and youngsters usually get 10-12 runny noses per year.