Risk factors

Your risk of becoming infected with the varicella-zoster virus that causes chickenpox is higher if you haven't already had chickenpox or if you haven't had the chickenpox vaccine. It's especially important for people who work in child care or school settings to be vaccinated.

Most people who have had chickenpox or have been vaccinated against chickenpox are immune to chickenpox. A few people can get chickenpox more than once, but this is rare. If you've been vaccinated and still get chickenpox, symptoms are often milder, with fewer blisters and mild or no fever.