You may recall as a child catching the itchy red rash, chicken pox. The unsightly infection was caused by the varicella zoster virus and was responsible for nearly 4 million cases each year, until a vaccine introduced in 1995 reduced that number by 83 percent. Varicella zoster can lie dormant in the body for decades, and if activated can lead to herpes zoster, more commonly referred to as shingles, according to a new study.