" Symptoms of the Chickenpox Chickenpox used to be one of the most common viruses to affect children before its vaccination became available in the United States in 1995. Its symptoms include a rash across the body, as well as mild fever. The virus is highly contagious and spreads quickly in contained groups, and you are immune to it once you have contracted it. Most people have experienced chickenpox by adulthood. If you work in childcare ...