Chicken pox and shingles are a herpes 3 type virus also known as Varicella-zoster viruses. Chicken pox is a varicella virus and shingles is a zoster virus.
Mono is a herpes 4 virus. Roseola is a herpes 6 virus.

I read an article regarding herpes viruses and brain tumors. They did a study and found that as many as 90% of brain tumor patients were positive for a herpes virus within their brain. If I remember correctly this was a variant of herpes virus 6 & 7.

Herpes viruses are very opportunistic viruses and can cause absolutely no symptoms at all. They are pretty tricky little guys.

BTW - I don't think I have ever had mono. During my dx period I had so many tests done and I believe they included this test as DDs and DBF had mono shortly before my 1st major attack and subsequent diagnosis. I had quite a few blood tests done and nothing showed up as a positive so I can't make an assumption that it was mono that triggered this. Also, with so many people having had mono, I don't really believe that is a cause for MS.