On Immunity: An Inoculation

by Eula Biss

Once you are infected with chicken pox, the varicella virus never leaves your body. It lives in your nerve roots and must be kept at bay by your immune system for the rest of your life. In times of stress, it can return as shingles, a painful inflammation of the nerves. The reawakened virus can cause strokes and paralysis, but the most common complication of shingles is nerve pain that persists for months or years. Immunity produced by disease, in this case, involves an ongoing relationship with the disease. The vaccine virus that protects against chicken pox can also remain in a person’s nervous system. But being a weakened virus, it is far less likely to reawaken as shingles. And when it does, it is less likely to cause a severe case of shingles.