The MMRV vaccine combines the attenuated virus MMR (measles, mumps, rubella) vaccine with the addition of the chickenpox vaccine or varicella vaccine (V stands for varicella). The MMRV vaccine is typically given to children between one and two years of age. Several companies supply MMRV vaccines. ProQuad is marketed by Merck and was approved in 2005, for use in the United States by the Food and Drug Administration (FDA) for children ages twelve months through twelve years. An MMRV vaccine called Priorix Tetra by GlaxoSmithKline has been approved in Germany and Australia.