Curiosities: Is it possible to catch the same cold more than once?

Probably not the exact same cold, says Jonathan Temte, an associate professor of family medicine at UW–Madison. “With an infection, you will mount an immune response that is specific to that particular strain, but the common cold is usually caused by a rhinovirus, and well over 100 rhinovirus strains affect people.”

Because colds are seldom serious, Temte admits there is a limited amount of available research. But research on influenza supports the idea that a new cold is likely to be caused by an unfamiliar virus.

“If you have had influenza, and a similar strain of virus is around two years in a row, in the second year you are likely not to come down with anything, or will have a very mild case. The more change there is in proteins on the surface of the virus, the more likely they are to escape your immune system.”

Colds are most infectious two to three days after symptoms start, and a person may remain infectious for five or six days from the start of symptoms. The best advice for staying healthy during the winter is to avoid contact with people who are coughing or sneezing.

“Most colds are transmitted through respiratory droplets,” Temte says. “Remind children to cover their coughs and sneezes. Wash your hands frequently, especially in public, or when you know you’ve been around somebody with a respiratory infection.”