Live-attenuated varicella vaccine.

This article reviews the history and development of live attenuated varicella vaccine from its early days in Japan to its widespread use throughout the world. The vaccine has proven extremely safe after immunization of as many as 10 million healthy children and adults in the United States alone. The vaccine is also highly immunogenic and offers close to 100% protection from severe chickenpox and 90% protection from illness. It is expected to have a major impact on the epidemiology of varicella and zoster in countries with high vaccine uptake.