Get Vaccinated. If you are old enough to ask the question you are old enough to have had the vaccine (first widely given in the 90's).If you had it before, you won't get it again.If susceptabe, get the vaccine (if not pregnant). You only have to be briefly in a room with an infected person to get it. Adults are at higher risk than kids of major side effects like encephalitis and pneumonia.
Depends. How old are you? Have you had the vaccine? Are you pregnant? Mostly, avoid others with the varicella virus and wash your hands frequently. If you haven't had the vaccine, ask your doctor if you can or should get it.