Yes, this is theoretically possible, although rare. When the cold sore virus enters a person’s body for the first time, no typical cold sore will be seen. Most often, this happens ‘asymptomatically’ (without any symptoms) and if they do arise, these will take the form similar to a mild cold.
Transfer of cold sore viruses usually takes place during childhood with the cold sores emerging decades later. This is because a child’s immune system is usually weaker – this explains why children are often full of the cold when first attending school.
It is unusual for a cold sore virus to first enter the body during adulthood and if this is the case, it is often a signal of a weakening of the immune system.