A second dose of the chickenpox varicella vaccine is now available for children born on or after January 1, , who are at least 12 months to 11 years of age. This safe, effective booster will provide added protection against this highly contagious illness. The first dose varicella vaccine is recommended for children between 12 and 15 months. The second dose of varicella should be given as MMRV vaccine at years of age. New MMRV vaccine adds chickenpox protection to the measles, mumps, and rubella vaccine.