When Iwas very young, 13 on into high school I would get one cold sore after another. So very embarrassing for a school kid! These were not little ones, they were big, swollen and awful looking. One would start healing and I would get another one. My Mom finally took me to our GP and he gave me a series of small pox shots. He said it was the same virus that causes both. That took care of the problem. I only have maybe a small one when I have a fever, too much sun or way too much stress. I am now 54 so this has worked for all these years.
Hope this info might help some one.