"Being a parent reduces your risk of catching a cold -- possibly because of unknown 'psychological or behavioral differences between parents and nonparents'"" - ʎəlɹoɯ uəʞ from Bookmarklet

"The risk of becoming ill after exposure to cold viruses is reduced by about half in parents compared to nonparents, regardless of pre-existing immunity." - ʎəlɹoɯ uəʞ

"Kids get colds, and parents may develop protective antibodies against the specific viruses causing those colds. However, the lower risk of colds in parents could not be explained by pre-existing immunity, based on levels of antibodies to the study viruses. Parents were less likely to develop colds whether or not they had protective levels of antibodies." - ʎəlɹoɯ uəʞ

"The protective effect of parenthood increased along with the number of children. Parents were at reduced risk of colds even when they didn't live with any of their children. In fact, parents with no children at home had an even larger, 73 percent reduction in risk." - ʎəlɹoɯ uəʞ