They go together. But they don't have to anymore, thanks to the chickenpox vaccine. Chickenpox or varicella is a very contagious disease affecting 95 percent of the American population by age 18. Four million cases occur each year in the United States, mainly in children ages five to nine. Typically, chickenpox means worry and lost workdays for parents.
Children feel sick.
They have fever. They miss school and extracurricular activities. Chickenpox is especially risky for children with certain diseases, such as leukemia. However, it can be serious or fatal in healthy children too. And there is no way to know beforehand how chickenpox will affect your healthy child.