Kissing an Infected Person
A common myth about cold sores is that once they have scabbed over that they are no longer contagious. However, this is not the case. A cold sore may scab and shed several times before it’s healed, and during this scabbing period, cold sores are still very contagious.
Most cold sores last for 7 to 10 days, which is considered the contagious period. To be sure, a cold sore should be completely healed before it can be considered to no longer be contagious. While you can catch HSV from someone who does not currently have a cold sore, the virus is far less likely to be transmitted during this time.