In the latest Vaccine Smarts column by UTMB’s Dr. Richard Rupp and Bridget Hawkins: After the chickenpox goes away, the varicella virus remains in the nerve roots for the rest of our lives. Our immune system controls the virus and, for the most part, it remains quiet and doesn’t cause any problems. If the immune system fails, the virus moves down the nerve from the root to infect the skin, causing blisters. The medical term for the rash is herpes zoster, but it is better known as shingles.