Highly contagious childhood disease caused by the varicella zoster virus, and for which there is a vaccine to provide immunity.

Chicken pox is a highly contagious childhood disease that, until the vaccine became available in the mid-1990s, affected nearly all children under the age of ten years. In the late 1980s, there were a reported 3.9 million cases of chicken pox each year in the United States. The American Academy of Pediatrics estimates that more than 95% of the population contracted chicken pox prior to the availability of the vaccine. Most cases are fairly mild, with the child suffering seven to ten days of discomfort. A small percentage of chicken pox sufferers require hospitalization. Chicken pox is highly contagious. A person with chicken pox is contagious from one to two days before the outbreak of the chicken pox rash, and for six days after the rash erupts...