Varicella Vaccine

Varicella vaccine, also known as chickenpox vaccine, is a vaccine that protects against chickenpox, with one dose preventing 95 percent of moderate disease and 100 percent of severe disease, and two doses more effective still. A live attenuated varicella vaccine using the Oka strain was developed by Michiaki Takahashi and colleagues in Japan in the early 1970s, and American vaccinologist Maurice Hilleman's team developed a version based on the Oka strain in the United States in 1981, which first became commercially available in 1984 and was licensed for use in the US under the brand name Varivax in 1995. The vaccine is available either by itself or combined with the MMR vaccine as the MMRV vaccine, and a related vaccine, the zoster vaccine, is used to prevent disease caused by the same virus later in life. It is on the World Health Organization's List of Essential Medicines.